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Bulletin of the Polish Academy of Sciences Technical Sciences

Bulletin of the Polish Academy of Sciences Technical Sciences

Description

The Bulletin of the Polish Academy of Sciences Technical Sciences is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred:

  • Artificial and Computational Intelligence,
  • Biomedical Engineering and Biotechnology,
  • Civil Engineering,
  • Control, Informatics and Robotics,
  • Electronics, Telecommunication and Optoelectronics,
  • Mechanical and Aeronautical Engineering, Thermodynamics,
  • Material Science and Nanotechnology,
  • Power Systems and Power Electronics.

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Journal Metrics:
JCR Impact Factor 2022: 1.2
5 Year Impact Factor 2020: 1.490
CiteScore 2022: 2.8
SCImago Journal Rank (SJR) 2022: 0.285
Source Normalized Impact per Paper (SNIP) 2022: 0.543
Ministry of Education and Science: 100 points

Abbreviated title: Bull. Pol. Acad. Sci. Tech. Sci.
ISSN
ISSN 2300-1917

Editorial Board 2023-2025

Editor-in-Chief:

A. Rogalski, Military University of Technology

Honorary (Past) Editor-in Chief:

T. Kaczorek, Warsaw University of Technology

M.P. Kaźmierkowski, Warsaw University of Technology

Deputy Editor-in-Chief:

B. Błachowski, Institute of Fundamental Technological Research PAN

M. Mrozowski, Gdansk University of Technology

Board of Topical Co-editors:

Artificial and Computational Intelligence

S. Osowski, B. Sawicki and T. Leś, Warsaw University of Technology

Biomedical Engineering and Biotechnology

D. Pijanowska, Institute of Biocybernetics and Biomedical Engineering PAN

Civil Engineering

L. Czarnecki, Building Research Institute, ITB, Warsaw

Ł. Sadowski, Wroclaw University of Science and Technology

Control, Robotics and Informatics

J. Klamka and A. Babiarz, Silesian Technical University

J. Stefanowski, Poznan University of Technology

Electronics, Telecommunication and Optoelectronics

M. Mrozowski and A. Lamęcki, Gdansk University of Technology

Mechanical and Aeronautical Engineering, Thermodynamics

B. Błachowski, Institute of Fundamental Technological Research PAN

G. Zboiński, Institute of Fluid-Flow Machinery PAN and University of Warmia and Mazury in Olsztyn

Materials Science and Nanotechnology

B. Major and P. Czaja, Institute of Metallurgy and Materials Science PAN

Power Systems and Power Electronics

J. Rąbkowski and M. Jasiński, Warsaw University of Technology

International Editorial Advisory Board

R. Asthana, University of Wisconsin-Stout, Menomonie, USA

Xu Binshi, China Association of Plant Engineering, Beijing, P.R. China

F. Blaabjerg, Aalborg University, Denmark

C. Cecati, University of L’Aquila, Italy

A. Cichocki, RIKEN Institute, Tokyo, Japan

M. David, National Polytechnique de Toulouse, France

R. Ebner, Materials Centre Leoben, Leoben, Austria

E. Fornasini, University of Padova, Padova, Italy

L.G. Franquelo, University of Sevilla, Spain

M. Gad-el-Hak, Virginia Commonwealth University, Richmond, USA

M. Giersig, Free University of Berlin, Germany

D. van Gemert, Catholic University Leuven, KU Leuven, Belgium

L. Keviczky, Hungarian Academy of Sciences, Budapest, Hungary

V. Kučera, Czech Technical University in Prague, Prague, Czech Republic

R. Kennel, Technical University Munich, Germany

T.A. Kowalewski, Institute of Fundamental Technological Research PAN

E. Levi, Liverpool John Moore University, UK

G. Maier, Technical University of Milan, Milan, Italy

K.F. Man, City University of Hong Kong,

R. Maniewski, Institute of Biocybernetics and Biomedical Engineering PAN

H.A. Mang, Austrian Academy of Sciences, Vienna, Austria

H. Mihashi, Tohoku University, Aoba-ku, Sendai, Japan

S. Mindess, University of British Columbia, Vancouver, Canada

D.A. Mlynski, University of Karlsruhe, Karlsruhe, Germany

A.S. Nowak, University of Michigan, Ann Arbor, USA

K. Ohnishi, Keio University, Yokohama, Japan

A. Öberg, Linköping University, Linköping, Sweden

W. Pedrycz, University of Alberta, Canada

M. Razeghi, Northwestern University, Evanston, USA

J. Rodriguez, University of Andres Bello, Santiago, Chile

J.V. Sloten, Catholic University Leuven, Leuven, Belgium

B.M. Wilamowski, University of Auburn, Alabama, USA

A.L. Yarin, University of Illinois at Chicago, USA

Du Xiangwan, Chinese Academy of Engineering, China

J. Żurada, Department of Computer Engineering, University of Louisville, USA

Editorial Office:

Pałac Kultury i Nauki

Wydział IV Nauk Technicznych PAN

Pl. Defilad 1

PL 00-901 Warszawa

Managing Editor:

Renata Podraza, e-mail: Renata.Podraza@pan.pl

Finance:

Katarzyna Łasak, e-mail: Katarzyna.Lasak@pan.pl

The Bulletin of the Polish Academy of Sciences Technical Sciences is an open access journal with all content available with no charge in full text version.


The journal content is available under the licencse CC BY 4.0 https://creativecommons.org/licenses/by/4.0/.

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Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access

1 Development of an Advanced Control Algorithm for DAB DC/DC Converters: Inrush Current Limitation and Enhanced Operation in Transient States.
Serafin Bachman , Marek Turzyński
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e150328 | DOI: 10.24425/bpasts.2024.150328
Keywords: dual active bridge bidirectional isolated DAB efficiency control loop transient stateproblems analytical calculations DC/DC converter
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Abstract

The publication addresses the dynamic state challenges encountered during development of a Dual Active Bridge (DAB) converter within DC microgrid systems. The conventional startup method is identified as instigating a cascade of unfavorable outcomes, encompassing elevated starting current, transformer current asymmetry, DC voltage distortions, EMI and heightened thermal stress on semiconductor components. Additionally, it necessitates precise calibration of magnetic components and diodes. A proposed remedy to these issues is introduced, involving a control method based on an additional phase shift to modulate the current of the primary H bridge. This novel control methodology is posited as a means to mitigate the aforementioned undesirable effects associated with traditional converter initiation techniques. The research also delves into considerations of proper design procedure for the converter. Emphasis is placed on integrating the novel control methodology into the design framework to effectively address challenges arising during transient states. Validation of the proposed solution is substantiated through a series of laboratory tests, the results of which are comprehensively presented in the article. These tests affirm the efficiency of the system when incorporating the novel control methodology, thereby substantiating its practical utility in mitigating the identified issues during the initiation phase of the DAB converter in DC microgrid systems.
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Authors and Affiliations

Serafin Bachman
ORCID: ORCID
Marek Turzyński
2 Verification of the MLP network-based current sensor fault classifier for vector-controlled AC motor drives
Krystian Teler , Maciej Skowron , Teresa Orłowska-Kowalska
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e150336 | DOI: 10.24425/bpasts.2024.150336
Keywords: ac motor drives current sensor faults fault classification neural networks universal faultclassifier
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Abstract

In modern drive systems, the aim is to ensure their operational safety. Damage can occur not only to the components of the motor itself but also to the power electronic devices included in the frequency converter and the sensors in the measurement circuit. Critical damage to the electric drive that makes its further exploitation impossible can be prevented by using fault-tolerant control (FTC) algorithms. These algorithms are very often combined with diagnostic methods that assess the degree and type of damage. In this paper, a fault classification algorithm using an artificial neural network (ANN) is analysed for stator phase current sensors in AC motor drives. The authors confirm that the investigated classification algorithm works equally well on two different AC motors without the need for significant modifications, such as retraining the neural network when transferring the algorithm to another object. The method uses a stator current estimator to replace faulty sensor measurements in a vector control structure. The measured and estimated currents are then subjected to a classification process using a multilayer perceptron (MLP), which has the advantage of a small structure size compared to deep learning structures. The uniqueness of the method lies in the use of data in the training set that are not dependent on the parameters of a specific motor. Four types of current sensor faults were studied, namely total signal loss, gain error, offset, and signal saturation. Simulations were performed in a MATLAB/SIMULINK environment for drive systems with an induction motor (IM) and a permanent magnet synchronous motor (PMSM). The results show that the algorithm correctly evaluates the type of damage in more than 99.6% of cases regardless of the type of motor. Therefore, the results presented here may help to develop universal diagnostic methods that will work on a wide variety of motors.
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Authors and Affiliations

Krystian Teler
Maciej Skowron
Teresa Orłowska-Kowalska
ORCID: ORCID
3 The effect of coating process thermal cycle on mechanical properties of AA6061-T6 used for load-carrying elements of a space instrument: a case study
Tomasz Barciński , Robert Kosturek , Tomasz Kowalski , Maciej Bzowski , Roman Wawrzaszek , Karol Mostowy , Jędrzej Baran , Maciej Daukszo
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e150338 | DOI: 10.24425/bpasts.2024.150338
Keywords: mechanical properties aluminum satellite thermal cycle safety factor
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Abstract

Components used for the structure of the GLObal Solar Wind Structure experiment in the NASA Interstellar Mapping and Acceleration Probe space mission, made of AA6061-T6 alloy, are subjected to the coating process, where the temperature affects its mechanical properties. The aim of this paper is to examine the impact of the coating thermal cycle on the mechanical properties of AA6061-T6 alloy, which is the load-carrying material in a spaceborne instrument. As a part of the manufacturing process, the parts made of AA6061-T6 are subjected to a coating process at a temperature of about 220°C for a time longer than 1h. This treatment modifies the mechanical properties of the alloy. To evaluate the consequences of this change for spaceborne components, mechanical testing and numerical simulation were carried out. It was found that as a result of the coating process, the reduction in AA6061-T6 yield strength is about 16%, which entails a decrease in the margins of safety by 25% at its maximum.
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Authors and Affiliations

Tomasz Barciński
Robert Kosturek
ORCID: ORCID
Tomasz Kowalski
Maciej Bzowski
Roman Wawrzaszek
Karol Mostowy
Jędrzej Baran
Maciej Daukszo
4 Investigating the effect of electrospark alloying parameters on structure formation of modified nitrogen coatings
Oksana HAPONOVA , Viacheslav TARELNYK , Tomasz MOŚCICKI , Nataliia TARELNYK
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e150802 | DOI: 10.24425/bpasts.2024.150802
Keywords: electrospark alloying discharge energy productivity coating structure
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Abstract

The quality parameters of surface layers synthesised using electrospark alloying (ESA) technology were analysed in this paper. The main focus was on the influence of equipment energy parameters on structure formation, specifically the effect of discharge energy and productivity. Microstructural analysis of the modified surface of C40 steel after nitriding by ESA using a paste containing nitrogen compounds injected into the interelectrode gap was conducted. The layer structure for all studied ESA parameters includes three areas: the upper "white layer", the diffusion zone below it and the substrate. The roughness of the surface is Ra ~ 0.9 μm at low discharge energy Wp = 0.13 J and Ra ~ 6 μm at Wp = 3.4 J. The microhardness, continuity, and surface roughness of the layers varied with Wp. The influence of ESA productivity on the structure was studied. The thickness of the hardened layer and the diffusion zone, as well as the microhardness and continuity, are affected by reduced productivity. For the same discharge energy, the thickness of the hardened layer increases by 10-18% with decrease in productivity compared to the classical mode. Studies have shown that a productivity loss has a positive effect on the quality characteristics of the coatings produced by the ESA process.
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Authors and Affiliations

Oksana HAPONOVA
Viacheslav TARELNYK
Tomasz MOŚCICKI
Nataliia TARELNYK
5 Performance Evaluation of 5G New Radio Low Density Parity Check Codes over Different Scenarios of Lognormal Fading Channel
Mohammed Hussein Ali , Ghanim A. Al-Rubaye
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e150808 | DOI: 10.24425/bpasts.2024.150808
Keywords: QAM OFDM NR-LDPC lognormal fading channel BER 5G NR physical uplink shared channel (PUSCH) physical downlink control channel (PDCCH) enhanced mobile broadband (eMBB) LTE-advanced (LTE-A)
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Abstract

Low Density Parity Check (LDPC) is a channel coding technique widely utilized in the 5G New Radio standard, it is of utmost importance in facilitating proficient and secure communication in noisy environments by effectively minimizing errors during data transmission. It is primarily used in the 5G New Radio (NR) standard for encoding user information on the Physical Downlink Shared Channel (PDSCH). The necessity to satisfy the increasing expectations for throughput, latency, and dependability led to the decision to deploy LDPC codes for user data, especially in the enhanced mobile broadband (eMBB) and ultra-reliable and low-latency communications (URLLC) scenarios of 5G networks. The present system proposes the use of NRLDPC codes for the purpose of transmitting data across a lognormal multipath fading channel model in the presence of AWGN. Wireless communication channels often use a lognormal multipath fading channel model, where the received signal experiences both multipath fading and lognormal shadowing. The research investigates the effectiveness of NR-LDPC coding in improving QAM-OFDM system performance by analyzing two rate-compatible base graphs and comparing their effectiveness with an uncoded system. This analysis is crucial for optimizing communication network design, especially in scenarios where the integrity of data is of utmost importance. We introduce a new method to improve the 5G NR LDPC code capability under lognormal fading conditions. This approach develops a layered Min Sum (LMS) algorithm to provide enhanced error correcting capabilities. The developed and implemented decoding algorithm represents a significant advancement over traditional detection methods. The outcomes of the simulation provide evidence of the effectiveness of the proposed NR-LDPC coding techniques in terms of their error correction and identification capabilities. In addition, the developed LMS decoding algorithm has been shown to significantly decrease the BER of the system.
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Authors and Affiliations

Mohammed Hussein Ali
Ghanim A. Al-Rubaye
6 Failure analysis of Fiber Metal Laminate channel section column under axial compressive pulse loading
Monika Zaczynska
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151048 | DOI: 10.24425/bpasts.2024.151048
Keywords: Fiber Metal Laminates dynamic buckling failure analysis numerical simulations
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Abstract

The study aims to analyse the dynamic buckling phenomenon and assess the role of the stress tensor components in the failure process of a short Fiber Metal Laminate column under axial compressive dynamic loading. The investigation is focused on a channel-section profile composed of three aluminium layers and two doubled composite plies [Al/0/90/Al/90/0/Al]. The numerical analysis was performed on the finite element model, which was validated by experimental static buckling tests. Employing a progressive failure algorithm, this analysis incorporated the material property degradation method and Hashin’s criterion as the damage initiation criterion. Failure initiation in metal layers was based on the HuberMises-Hencky failure criterion. Based on the conducted analyses, it was concluded that the dominant forms of destruction in the FML structure are yielding in the metal layers due to excessive compressive stresses and the failure of the matrix in composite plies as a result of compressive and shear stresses. Through a thorough examination of the stress tensor components, critical stresses contributing to aluminum plastic deformation and laminate failure mechanisms were identified.
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Authors and Affiliations

Monika Zaczynska
7 Experimental investigations on ultralightweight-concrete encased cold-formed steel structures: Local stability behaviour of Csection profiles subjected to eccentric compression
Ahmed Alabedi , Péter Hegyi
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151044 | DOI: 10.24425/bpasts.2024.151044
Keywords: cold-formed steel experimental test lightweight concrete continuous bracing sustainability
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Abstract

Nowadays, cold-formed steel (CFS) has become widely used in the field of lightweight structures. In 2016, the Budapest University of Technology and Economics initiated a research on a unique structural system using CFS and utilized ultra-lightweight concrete as an encasing material. This material serves as a continuous bracing that improves CFS element resistance, stability behaviour, and performance, while also providing heat insulation capabilities, thus helping achieving sustainability goals. This paper is considered a continuation of previous research conducted by the authors. An experimental investigation was carried out on encased CFS columns subjected to eccentric loading. A total of fourteen stub-columns, with two distinct thicknesses, were subjected to various loading conditions for testing. The test results showed that local failure controlled the behaviour of all the tested elements. The reduction in capacity resulting from eccentricity with respect to centric resistance varied between 20% and 52%, depending on the applied load position and the core thickness of the tested steel elements. Moreover, the test outcomes were compared to the Eurocode analytical solution of pure steel elements. The overall load increment ranged from 46% to 18%, with a more noticeable bracing impact observed in the case of slender elements. Material test also supplement the results.
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Authors and Affiliations

Ahmed Alabedi
Péter Hegyi
8 Experimental evaluation of low-voltage DC/DC boost converters for renewable energy applications
Jakub Dawidziuk , Michał Harasimczuk , Rafał Kopacz
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e150810 | DOI: 10.24425/bpasts.2024.150810
Keywords: renewable energy boost DC/DC converters high-efficiency converters current-fed converters
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Abstract

The demand for energy in the world is growing, and the requirements for the efficiency of energy-saving technologies used in renewable energy sources, especially prominent in terms of power electronics, are also increasing. In many renewable energy applications, high-efficiency, high-power DC/DC converters are necessary as an interface between various low-voltage sources and higher output voltage loads, e.g., in photovoltaics. The article presents a comprehensive study on reducing power losses in electric energy conversion in modified isolated and non-isolated DC/DC boost converters powered by low-voltage energy sources. The main desirable features, such as high energy efficiency, high conversion ratio, and low stress on the switches and diodes, were compared and further experimentally validated. The experimental evaluation indicates that the highest efficiency of 96.7%, with a conversion ratio of more than 10, was achieved in the interleaved boost-flyback DC/DC converter. Other investigated systems, namely non-isolated push-pull-boost converters, isolated half-bridge boost, and partially parallel boost converters, achieved slightly lower efficiency. Simultaneously, using the suggested topology, the passive component count was reduced. Furthermore, better utilization of switches and a higher conversion ratio are provided, as well as a possibility of working at a lower duty cycle compared to other step-up converter topologies. All in all, the proposed and studied converters exhibit certain advantages over other state-of-the-art solutions and thus can be competitively and effectively employed in modern low-voltage DC/DC applications such as photovoltaics.
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Authors and Affiliations

Jakub Dawidziuk
ORCID: ORCID
Michał Harasimczuk
ORCID: ORCID
Rafał Kopacz
9 Cascade-Free Predictive Adhesion Control for IPMSM-Driven Electric Trains
Jiao Ren , Ruiqi Li
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151375 | DOI: 10.24425/bpasts.2024.151375
Keywords: adhesion control cascade-free maximize longitudinal acceleration force perturbation and observation predictive speed control
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Abstract

The application of active adhesion control to the traction control system of an electric train holds great appeal for maximizing longitudinal acceleration force. Most of the currently reported works regulate the adhesion between wheel and rail by adjusting the torque reference of a cascade motor drive controller, which suffers from slow speed response and excessive start torque. This article proposes a cascade-free predictive adhesion control strategy for electric trains powered by an interior permanent magnet synchronous motor (IPMSM) to address these issues. The proposed control scheme utilizes an improved perturbation and observation method to predict the time-varying wheelrail adhesion state and determine the optimal slip speed. The initial setpoint reference command from the driver master is then adjusted to a dynamic reference that continuously adapts to the predicted adhesion conditions. Finally, the predictive speed control method is employed to ensure rapid convergence of the tracking objective. The simulation and hardware-in-the-loop testing results confirm that this approach achieves excellent dynamic performance, particularly during the train start-up phase and in the high-speed weak magnetic area of the IPMSM.
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Authors and Affiliations

Jiao Ren
Ruiqi Li
10 Configuration design methodof hybrid electric agricultural machinery system based on layered two-dimensional matrix
Baogang Li , Jinbo Pan , Rui Sun , Yuhuan Li , Zunmin Liu , Wanyou Huang , Hanjun Jiang , Fuhao Liu
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151377 | DOI: 10.24425/bpasts.2024.151377
Keywords: composite power agricultural machinery multi-power output two-dimensional matrix
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Abstract

The working environment and objects of agricultural machinery are different from those of automobiles, andagricultural machinery is greatly affected by the working environment and working conditions, and the power output systemismore complex. Agricultural machinery not only has drive output, but also PTO output and hydraulic output, whichtogetherconstitute the output system of agricultural machinery. Agricultural machinery conditions can be dividedintoroadtransportation working conditions and field operation working conditions. The working conditions of agricultural machinerycan be divided into different load conditions according to the different traction tools and whether the hydraulic andPTOwork,such as ploughing, rotary tillage, fertilization, and transportation. Therefore, developing hybrid electric agricultural machinerysystems that are suitable for various complex working conditions holds great theoretical significance and practical value. Giventhe complex working conditions of agricultural machinery systems in agricultural work and the intricate challengesindesigning hybrid agricultural machinery systems. In this paper, the two-dimensional matrix is used to represent thephysicalstructure and dynamics of the multi-channel power output agricultural mechanism. A hierarchical two-dimensional matrixmethod for the generation and screening of hybrid electric agricultural machinery systems with multi-power output powerisproposed. The components of agricultural machinery are divided into an input layer and an output layer, and these componentsare coded and defined, and then transformed into a matrix. The hierarchical two-dimensional matrix method is usedtogenerateand screen the hybrid electric agricultural mechanism type. Through the stratification of the matrix, the complexityoftheconfiguration generation is reduced, and the constraints are applied to the basic screening of the generated configurations. Therationality of the configurations obtained after generation and screening is verified by Simulink simulation. The resultsshowthat the configuration screened by this method can meet the performance requirements of agricultural machinery.
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Authors and Affiliations

Baogang Li
Jinbo Pan
Rui Sun
Yuhuan Li
Zunmin Liu
Wanyou Huang
Hanjun Jiang
Fuhao Liu
11 An Improved Thermal Management of Lithium Based Batteries Employing Genetic Algorithm Optimization
Gökhan Yüksek , Timur Lale
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151378 | DOI: 10.24425/bpasts.2024.151378
Keywords: lithium-ion battery temperature energy management system renewable energy genetic algorithm
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Abstract

Lithium-based battery systems (LBS) are used in various applications, from the smallest electronic devices to power generation plants. LBS energy storage technology, which can offer high power and high energy density simultaneously, can respond to continuous energy needs and meet sudden power demands. The lifetime of LBSs, which are seen as a high-cost storage technology, depends on many parameters such as usage habits, temperature and charge rate. Since LBSs store energy electrochemically, they are seriously affected by temperature. High-temperature environments increase the thermal stress on the LBS and cause its chemical structure to deteriorate much faster. In addition, the fast charging feature of LBSs, which is presented as an advantage, increases the internal temperature of the cell and negatively affects the battery life. The proposed energy management approach ensures that the ambient temperature affects the charging speed of the battery and that the charging speed is adaptively updated continuously. So, the two parameters that harm battery health absorb each other, and the battery has a longer life. A new differential approach has been created for the proposed energy management system. The total amount of energy that can be withdrawn from the LBS is increased by 14.18% compared to the LBS controlled with the standard energy management system using the genetic algorithm optimized parameters. In this way, the LBS replacement period is extended, providing both cost benefits and environmentally friendly management by LBSs turning into chemical waste later.
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Authors and Affiliations

Gökhan Yüksek
ORCID: ORCID
Timur Lale
12 Differential vibrating-wire strain gauge for concrete deformation measurements
Adam Kanciruk , Elżbieta Matus
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151379 | DOI: 10.24425/bpasts.2024.151379
Keywords: measurement of deformations and displacements vibrating-wire measuring instruments strain gauge
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Abstract

The basic measuring element of vibrating-wire strain gauges is a steel piano wire, functioning in the elastic range. This element is constantly under tension. Therefore, its material gradually deforms permanently. This deformation causes its stress to relax. This relaxation results in a measurement errors of the strain gauges. This error, as demonstrated by both in situ and laboratory tests, can reach values of even several percent of the strain gauge measuring range (FSR) over periods of 10 years. Therefore, a concept of a differential strain gauge was proposed, for the construction of which two measuring wires would be used. Changing the input value of the strain gauge, i.e. a displacement of one of its anchors in relation to the other one would cause one wire to lengthen while the other wire shortened identically. The measured displacement would be calculated on the basis of the difference in the frequency of the wires vibrations. In this way, the influence of the simultaneous relaxation of the wires on the measurement result would be greatly reduced. Based on this concept, a prototype differential strain gauge for measuring concrete deformation was realized. In addition to two wires, it also contains two electromagnets, placed together with the wires in a common body-housing. After the strain gauge was assembled, its first tests were carried out under laboratory conditions.
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Authors and Affiliations

Adam Kanciruk
Elżbieta Matus
13 Review of surface metrology artifacts for additive manufacturing
Patryk Mietliński , Bartosz Gapiński , Jolanta B. Królczyk , Piotr Niesłony , Marta Bogdan-Chudy , Anna Trych-Wildner , Natalia Wojciechowska , Grzegorz M. Królczyk , Michał Wieczorowski , Tomasz Bartkowiak
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151380 | DOI: 10.24425/bpasts.2024.151380
Keywords: test artifacts 3D printing additive manufacturing surface metrology
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Abstract

Test artifacts, resembling real machine parts, allow quantitative evaluation of system performance and insight into individual errors, aiding in improvement and standardization in additive manufacturing. The article provides a comprehensive overview of existing test artifacts, categorized based on geometric features and material used. Various measurement techniques such as stylus profilometry and computed tomography are employed to assess these artifacts. It was shown that Selective Laser Melting (SLM) technology and titanium alloys are prevalent in artifact creation. Specific artifact categories include slits, angular aspects, length parameters, variable surfaces, and others, each accompanied by examples from research literature, highlighting diverse artifact designs and their intended applications. The paper critically discusses the main problems with existing geometries. It paper underscores the importance of user-friendly and unambiguous artifacts for dimensional control, particularly in surface metrology. It anticipates the continued growth of metrological verification in future manufacturing environments, emphasizing the need for precise and reliable measurement results to support decision-making in production conditions
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Authors and Affiliations

Patryk Mietliński
Bartosz Gapiński
Jolanta B. Królczyk
Piotr Niesłony
Marta Bogdan-Chudy
Anna Trych-Wildner
Natalia Wojciechowska
Grzegorz M. Królczyk
Michał Wieczorowski
Tomasz Bartkowiak
14 Two-Step Reinforcement Learning for Multistage Strategy Card Game
Konrad Godlewski , Bartosz Sawicki
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151376 | DOI: 10.24425/bpasts.2024.151376
Keywords: reinforcement learning incremental learning card games
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Abstract

This study introduces a two-step reinforcement learning (RL) strategy tailored for "The Lord of the Rings: The Card Game", a complex multistage strategy card game. The research diverges from conventional RL methods by adopting a phased learning approach, beginning with a foundational learning step in a simplified version of the game and subsequently progressing to the complete, intricate game environment. This methodology notably enhances the AI agent’s adaptability and performance in the face of the unpredictable and challenging nature of the game. The paper also explores a multi-phase system where distinct RL agents are employed for various decision-making phases of the game. This approach has demonstrated remarkable improvement, with the RL agents achieving a winrate of 78.5 % at the highest difficulty level.
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Authors and Affiliations

Konrad Godlewski
Bartosz Sawicki
15 Decision-support tools for diagnosing and selecting the optimal method of repairing buildings
Zbigniew Walczak , Barbara Ksit , Anna Szymczak-Graczyk
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151382 | DOI: 10.24425/bpasts.2024.151382
Keywords: plate deflection floor plate repair terrestrial laser scanning Fuzzy AHP method FAHP
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Abstract

This study introduces an innovative algorithm that leverages Terrestrial Laser Scanning (TLS) and the Fuzzy Analytic Hierarchy Process (FAHP) for the optimization of building repair methodologies. Focusing on multi-criteria decision-making (MCDM), it showcases a methodology for evaluating and selecting the most effective repair strategy for building elements, balancing various conflicting criteria. The research applies TLS for rapid and accurate geometric data acquisition of engineering structures, demonstrating its utility in structural diagnostics and technical condition assessment. A case study on a single-family residential building, experiencing floor deformation in a principal ground-floor room, illustrates the practical application. Maximum deflection and floor deflection distribution were measured using TLS. Utilizing FAHP for analysis, the decision model identifies the most advantageous repair method from a building user’s perspective. This approach not only provides a systematic framework for selecting optimal repair solutions but also highlights the potential of integrating advanced scanning technologies and decision-support methods in the field of building materials and structural engineering.
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Authors and Affiliations

Zbigniew Walczak
Barbara Ksit
ORCID: ORCID
Anna Szymczak-Graczyk
16 Assessing the equivalent spring modelling method of CFS elements encased in ultra-lightweight concrete
Ahmed Alabedi , Péter Hegyi
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151384 | DOI: 10.24425/bpasts.2024.151384
Keywords: plate buckling; numerical analysis; equivalent spring model; sustainability
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Abstract

An efficient finite element approach was recently developed to analyse encased cold-formed steel (CFS) structures. This new technique replaced encasing material with unidirectional springs, analogous to the Winkler foundation concept, to shorten the analysis time while ensuring accuracy and reliability in predicting the structural behaviour of encased CFS components. In this paper, the validity, and limitations of the simplified spring model to represent outstanding plates were assessed. The investigation demonstrated that the simplified spring model could effectively predict the ultimate load for a wide range of ultra-lightweight concrete moduli (50-250 MPa) with an acceptable error. The analysis indicated that plate elements initially in cross-section class 4 without encasing material become at least class 3, or better as a consequence of encasing. Previously reported experiments were used to evaluate the performance of the ESM. The analysis demonstrated that the ESM can accurately predict the local failure ultimate load of encased CFS sections with an acceptable error percent and significantly less computational effort than a 3D solid model.
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Authors and Affiliations

Ahmed Alabedi
Péter Hegyi
17 Trusses of the smallest total potential energy
Sławomir Czarnecki , Tomasz Lewiński
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151673 | DOI: 10.24425/bpasts.2024.151673
Keywords: topology optimization trusses prescribed displacements
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Abstract

The paper concerns the problem of minimization of the total potential energy of trusses subjected to static loads in the presence of prescribed displacements of selected supporting nodes. The positions of the internal (free) nodes are fixed and the supporting nodes are imposed, the member stiffnesses being design variables, while the truss volume represents the cost of the design. Due to the assumption of the stiffnesses being non-negative, the problem is reduced to a problem of optimization of structural topology. Upon eliminating all the design variables analytically the optimum design problem is eventually reduced to the two mutually dual problems expressed either in terms of member forces or in terms of displacements of free nodes. The problem setting concerning the case when the prescribed displacements of supports are the only loads applied (i.e. kinematic loads) assumes a particularly simple form. A specific numerical method of solving the stress-based auxiliary problem has been developed for the selected 2D and 3D optimal designs. The study is the first step towards topology optimization of trusses with distortions
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Authors and Affiliations

Sławomir Czarnecki
ORCID: ORCID
Tomasz Lewiński
ORCID: ORCID
18 An Algorithm for Automatically Arranging Flight Training Plans
Pengfei Sun , Jia Liu , Hao Nian
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151672 | DOI: 10.24425/bpasts.2024.151672
Keywords: flight day plan goal programming algorithm military aviation
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Abstract

With a continued strong pace of artificial intelligence, the way of formulating the flight day plan has a significant impact on the efficiency of flight training. However, through extensive research we find that the scheduling of flight days still relies on manual work in most military aviation academies. This method suffers from several issues, including protracted processing times, elevated error rates, and insufficient degree of optimization. This article provides a comprehensive analysis of automated flight scheduling using Goal Programming algorithm and details the implementation of the corresponding algorithm on the LINGO platform. The study enhances the flexibility and robustness of the model by setting bias variables, wherein the flight courses for students and instructors can be automatically and reasonably scheduled.
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Authors and Affiliations

Pengfei Sun
Jia Liu
ORCID: ORCID
Hao Nian
19 Optimized Design of Downhole Heater Seal for Oil Shale In-Situ Heat Injection
Qiang Li , Qingfeng Bu , Xiaole Li , Hao Zeng
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151383 | DOI: 10.24425/bpasts.2024.151383
Keywords: Oil shale In-situ conversion Downhole heater Numerical simulation High-temperature seal
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Abstract

Sealing is an important prerequisite for downhole heater work. This paper proposes a combination of soft and hard and welding sealing programs, which were analyzed using theoretical calculations, numerical simulation, and in-situ testing. The results show that 316 stainless steel can meet the stuffing seal requirements; The first stuffing compresses and gradually reduces, while the second stuffing essentially does not deform. Stuffing deformation to fill the gap in the sealing hole, resulting in a sealing layer. The compression rate is 0.43%, 8.45%, and 12.64%, indicating that the locking stress should be more than 2000 N; The temperature at the weld is heated by heat conduction and distributed in a concentric circle. Thermal stress will influence the 50mm barrier, but the 100mm boundary will be mostly unaffected. Actually, the thermal stress that destroys the weld seal may be reduced by adjusting the heater's output or raising the gas injection rate. During the beginning of the in-situ heat injection, the temperature of the heating rods rises simultaneously with the outlet temperature. As consequently, the two show opposite tendencies. The heat generated by the heating rods will cause the injected gas to be preheated in advance.
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Authors and Affiliations

Qiang Li
ORCID: ORCID
Qingfeng Bu
Xiaole Li
Hao Zeng
20 Experimental and numerical static tests of tensegrity triplex modules
Andrzej Rutkiewicz , Leszek Małyszko
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151674 | DOI: 10.24425/bpasts.2024.151674
Keywords: experimental test tensegrity triplex self-stress level force transducers struts buckling
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Abstract

The paper presents chosen results of experimental tests performed on physical mock-ups of tensegrity triplex modules, approximately 1.2 m tall and of 0.5 m diameter, made of steel. A uniform and uniaxial static compressive loading is applied to three upper nodes of the modules at six different self-stress levels. Cable forces are measured using specially crafted force transducers of an electro-resistive strain-gauge type. Two types of struts with different slenderness are incorporated to analyse the influence of buckling on the modules behaviour. A simple three-parameter mathematical model is presented in order to explain the modules’ behaviour and discuss the obtained experimental data. The results show nonlinear behaviour in the equilibrium path, as well as, rapidly decreasing axial stiffness in the post-critical phase. Increasement of prestress has a small influence on the stiffness in the chosen range of compressive loading. The experimental results are valuable for purposes of verification and validation of numerical studies and fill the lack of experimental data in the literature.
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Authors and Affiliations

Andrzej Rutkiewicz
Leszek Małyszko
21 Melanoma recognition using an ensemble of deep CNN structures
Fabian Gil , Stanisław Osowski
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151675 | DOI: 10.24425/bpasts.2024.151675
Keywords: CNN structures ensemble of classifiers melanoma recognition
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Abstract

The paper proposes a deep-learning approach to the recognition of melanoma images. It relies on the application of many different architectures of CNN combined in the form of an ensemble. The units of the highest efficiency are selected as the potential members of the ensemble. Different methods of arrangement of the ensemble members are studied and the limited number of the best units are included in the final form of an ensemble. The results of numerical experiments performed on the ISIC2017 database have shown the very high efficiency of the proposed ensemble system. The best accuracy in recognition of melanoma from non-melanoma cases obtained by the ensemble was 96.54% at AUC=0.9909, sensitivity 94.71%, and specificity 97.67%. These values are superior to the results presented for this ISIC2017 database.
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Authors and Affiliations

Fabian Gil
Stanisław Osowski
22 Kinematic Calibration of a Lightweight Manipulator for Medical Applications
Krzysztof Arent , Adam Kurnicki , Piotr Portasiak , Bartłomiej Stańczyk
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151381 | DOI: 10.24425/bpasts.2024.151381
Keywords: manipulator kinematics calibration medical robots
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Authors and Affiliations

Krzysztof Arent
Adam Kurnicki
Piotr Portasiak
Bartłomiej Stańczyk
23 Simulation study of flywheel energy storage assisted coal-fired unit frequency regulation
Shunyi Song , Tianshu Qiao , Rui Zhang , Shuangyin Liang , Yibing Liu
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151951 | DOI: 10.24425/bpasts.2024.151951
Keywords: flywheel energy storage; coal-fired unit frequency modulation characteristics
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Abstract

With the increasing proportion of renewable energy power generation, its accompanying intermittency and volatility problems are becoming increasingly prominent, and the frequency fluctuation of the power system is becoming increasingly severe. Participation in frequency regulation services can be economically rewarding for generating units. The flywheel energy storage system can effectively improve the frequency regulation capability of coal-fired units. In this paper, the improvement of the FM capability of coal-fired units in the operation of a two-area interconnected power system containing wind power is investigated, and a model of a two-area interconnected power system comprising a turbine generator, wind power, and flywheel energy storage is established. The enhancement of the FM capability of coal-fired units by adding a flywheel energy storage system is analysed. The simulation results show that adding the flywheel energy storage system improves the FM capability of the coal-fired unit to a considerable extent, and the coal-fired unit can decide the flywheel capacity it needs to be equipped with through detailed economic calculations.
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Authors and Affiliations

Shunyi Song
Tianshu Qiao
Rui Zhang
Shuangyin Liang
Yibing Liu
24 Traffic accident prediction method based on multi-view spatial-temporal learning
Jian Feng , Tianchao Liu , Yuqiang Qiao
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151955 | DOI: 10.24425/bpasts.2024.151955
Keywords: traffic accident prediction spatial-temporal dependencies accident precursor spatial heterogeneity
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Abstract

Traffic accident prediction is a crucial component of the Intelligent Traffic System, which is important to maintain citizen safety and decrease economic losses. Current deep learning based methods for traffic accident prediction fail to consider the driving mechanism of traffic accidents, so a novel traffic accident prediction method based on multi-view spatial-temporal learning is proposed, which represents the driving mechanism of traffic accidents from multiple views. Firstly, for the urban regions divided by grids, a new augmentation has been designed to augment the spatial semantic information of regions through learnable semantic embedding, then Deformable Convolutional Networks with non-fixed convolution kernels are used to learn dynamic spatial dependencies between regions and Gated Recurrent Units are used to learn temporal dependencies, which can capture dynamic spatial-temporal evolution patterns of traffic accidents. Secondly, Long Short-Term Memory is employed to learn the traffic flow breakdown from the flow difference of adjacent time steps in each region to recognize the traffic accident precursor in the risk environment. Thirdly, accident patterns in different regions are learned from historical traffic flow to determine whether the flow is the dominant factor and capture the spatial heterogeneity of traffic accidents. Finally, the above features are fused for accident prediction at the regional level. Experiments are conducted on 2 real datasets, and the experimental results show that the proposed method outperforms 8 benchmark methods
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Authors and Affiliations

Jian Feng
ORCID: ORCID
Tianchao Liu
Yuqiang Qiao
25 Study on the efficiency of small-scale wind turbine with rotor adapted for low wind speeds
Piotr Strojny
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151954
Keywords: wind turbine turbine rotor wind turbine efficiency wind tunnel tests of wind turbines fieldtests of wind turbines
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Abstract

The aim of this article is to present the results of tunnel tests and field tests of small-scale horizontal-axis wind turbines. The article proposes a new concept of turbine rotor adapted to improve efficiency at low wind speeds. The methodology for calculating the rotor and generator is shown. The turbine construction solution is presented briefly, along with the technology for manufacturing turbine components and assembly. An analysis of the obtained results is also carried out.
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Authors and Affiliations

Piotr Strojny
26 A random field-based simulational identification of possible levels of material imperfections of adhesive-bonded joints
Karol Winkelmann , Jan Faizullah , Łukasz Smakosz , Violetta Konopińska-Zmysłowska , Victor Eremeyev , Marcin Kujawa
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151678 | DOI: 10.24425/bpasts.2024.151678
Keywords: adhesive-bonded joints adhesive imperfections random fields probabilistic analysis reliability
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Abstract

Recently, structural adhesives have become significant in the shaping of structural elements, especially in thin-walled structures, where they replace or supplement traditional connection methods. However, adhesive-bonded joints are highly susceptible to internal structural imperfections due to their application technique and the nature of the adhesive. These material inconsistencies impact the strength parameters and the mechanical behavior of the entire connection. This study proposes a simplified method for the probabilistic numerical modeling of structural imperfections in an adhesive layer. The adhesive is modeled as an uncorrelated random field with weakened elements representing structural imperfections randomly scattered throughout its entire volume. The percentage of these imperfections (in relation to the total volume) is adopted a random variable. By conducting experimental tests on dogbone specimens of a selected adhesive and comparing them to adequate numerical tests with varying volumes of weakened elements, the determination of the representative imperfection volume of the investigated adhesive was possible. Based on these tests, the calibration of the probability density function to describe the volume of the imperfections may be performed. Furthermore, the application of the random model for an adhesive-bonded single lap-joint is shown to be viable. Finally, the calculation of a probability-based mechanical response (in this case, the normal force at critical elongation) of the single lap-joint with structural imperfections is performed, and its resultant reliability is assessed and evaluated.
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Authors and Affiliations

Karol Winkelmann
Jan Faizullah
Łukasz Smakosz
ORCID: ORCID
Violetta Konopińska-Zmysłowska
Victor Eremeyev
Marcin Kujawa
27 The influence of brace to chord rotational connection stiffness on stability of the truss
Marcin Krajewski
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151952 | DOI: 10.24425/bpasts.2024.151952
Keywords: truss stability connection rotational stiffness
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Abstract

The paper is devoted to the numerical analysis of the roof truss subjected to upward wind loading and braced at the tensioned top chord. The linear buckling analysis were performed for the beam and shell model of the structure. As the result the influence of rotational connection stiffness between the brace and the top chord on the truss stability was appointed. The biaxial strength testing machine was used to conduct the experimental tests of the rotational connection stiffness between selected steel profiles. The results in the form of measured structural displacements and rotations were presented. The static nonlinear analysis results performed for the shell model of the structural connection were compared to the results obtained on the experimental set-up.
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Authors and Affiliations

Marcin Krajewski
28 Prediction and Comparative Analysis of Emissions from Gas Turbines Using Random Search Optimization and Different MachineL earning Based Algorithms
Emrah Aslan
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151956 | DOI: 10.24425/bpasts.2024.151956
Keywords: emission gas turbines efficiency machine learning random search optimization
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Abstract

Gas turbines are widely used for power generation globally, and their greenhouse gas emissions have increasingly drawn public attention. Compliance with environmental regulations necessitates sophisticated emission measurement techniques and tools. Traditional sensors used for monitoring emission gases can provide inaccurate data due to malfunction or miscalibration. Accurate estimation of gas turbine emissions, such as particulate matter, carbon monoxide, and nitrogen oxides, is crucial for assessing the environmental impact of industrial activities and power generation. This study used 5 different machine learning models to predict emissions from gas turbines, including adaboost, xgboost, k-nearest neighbor, linear and random forest models. Random search optimization was used to set the regression parameters. The findings indicate that the adaboost regressor model provides superior prediction accuracy for emissions compared to other models, with an accuracy of 99.97% and a mean squared error of 2.17 on training data. This research offers a practical modeling approach for forecasting gas turbine emissions, contributing to the reduction of air pollution in industrial applications.
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Authors and Affiliations

Emrah Aslan
29 Flight Quality Assessment in Full Flight Phase Based on KOA-CNN-GRU-Self-Attention
Tianyi Wu , Zichun Lin , Jianan Huang
Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e151677 | DOI: 10.24425/bpasts.2024.151677
Keywords: KOA (Kepler Optimization Algorithm) CNN GRU self-attention flight quality
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Abstract

The main causes of aviation accidents in recent years are mostly related to pilot operational errors and pilot operational characteristics directly reflect flight quality, so flight quality and flight safety are inseparable. Improving the assessment method of flight quality is of great significance for building a competency-based and evidence-based flight training system as well as enhancing flight safety. However, some of the existing researches have the problems of being one-sided and the assessment accuracy is not high. We propose a flight quality assessment method based on KOA-CNN-GRU-Self-Attention for the whole flight phase to accurately assess the flight quality and to improve and supplement the existing system. Firstly, the QAR data of the whole flight phase is selected and divided into three data sets according to the three indexes of operational smoothness, accuracy, promptness, which are respectively substituted into the PCA comprehensive evaluation model to assess the flight quality. Then, the evaluation results are labelled with the rating as the input of CNN-GRU-Self-Attention, and the parameters are optimized using KOA. Finally, the evaluation of flight quality for the three indexes was achieved by training the KOA-CNN-GRU-Self-Attention model. The test results show that the accuracy of operational smoothness, accuracy, and promptness reaches 98.73%, 95.07%, and 97.18%, respectively, and the assessment effect is better and higher than the existing model. The model is also compared and analyzed with three base models CNN, QDA, XGBoost and three fusion models CNNSelf-Attention, GRU-Self-Attention, CNN-GRU-Self-Attention, which show overall better results in accuracy, recall, precision and F1-Score.
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Authors and Affiliations

Tianyi Wu
Zichun Lin
Jianan Huang

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