Applied 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 2023:	1.2
5 Year Impact Factor 2022:	1.1
CiteScore 2023:	2.8
SCImago Journal Rank (SJR) 2023:	0.282
Source Normalized Impact per Paper (SNIP) 2023:	0.573
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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Content

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6

1 Contents 6/2023

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6

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2 Selected problems of rotating machinery dynamics

Tomasz Szolc

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e148442 | DOI: 10.24425/bpasts.2023.148442

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Authors and Affiliations

Tomasz Szolc

e-mail:

ORCID:

Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Pawi´nskiego 5B, 02-106 Warsaw, Poland

3 Suppression of rotating machine shaft-line torsional vibrations by a driving asynchronous motor using two advanced control methods

Paweł Hańczur , Tomasz Szolc , Robert Konowrocki

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147925 | DOI: 10.24425/bpasts.2023.147925

Keywords: rotating machine drive system asynchronous motor torsional vibrations control methods

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Abstract

Many industrial rotating machines driven by asynchronous motors are often affected by detrimental torsional vibrations. In this paper, a method of attenuation of torsional vibrations in such objects is proposed. Here, an asynchronous motor under proper control can simultaneously operate as a source of drive and actuator. Namely, by means of the proper control of motor operation, it is possible to suppress torsional vibrations in the object under study. Using this approach, both transient and steady-state torsional vibrations of the rotating machine drive system can be effectively attenuated, and its precise operational motions can be assured. The theoretical investigations are conducted by means of a structural mechanical model of the drive system and an advanced circuit model of the asynchronous motor controlled using two methods: the direct torque control – space vector modulation (DTC-SVM) and the rotational velocity-controlled torque (RVCT) based on the momentary rotational velocity of the driven machine working tool. From the obtained results it follows that by means of the RVCT technique steady-state torsional vibrations induced harmonically and transient torsional vibrations excited by switching various types of control on and off can be suppressed as effectively as using the advanced vector method DTC-SVM.

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Authors and Affiliations

Paweł Hańczur

1 2

Tomasz Szolc

e-mail:

ORCID:

Robert Konowrocki

e-mail:

ORCID:

Institute of Fundamental Technological Research of the Polish Academy of Sciences, ul. Pawinskiego 5B, 02-106 Warsaw, Poland
Schneider Electric Polska Sp. z o.o, ul. Konstruktorska 12, 02-673 Warsaw, Poland

4 Exploiting gyroscopic effects for resonance elimination of an elastic rotor utilizing only one piezo actuator

Jens Jungblut , Daniel Franz , Christian Fischer , Stephan Rinderknecht

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147060 | DOI: 10.24425/bpasts.2023.147060

Keywords: active vibration control piezoelectric bearing gyroscopic effects active damping

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Abstract

A gyroscopic rotor exposed to unbalance and internal damping is controlled with an active piezoelectrical bearing in this paper. The used rotor test-rig is modelled using an FEM approach. The present gyroscopic effects are then used to derive a control strategy which only requires a single piezo actuator, while regular active piezoelectric bearings require two. Using only one actuator generates an excitation which contains an equal amount of forward and backward whirl vibrations. Both parts are differently amplified by the rotor system due to gyroscopic effects, which cause speed-dependent different eigenfrequencies for forward and backward whirl resonances. This facilitates eliminating resonances and stabilize the rotor system with only one actuator but requires two sensors. The control approach is validated with experiments on a rotor test-rig and compared to a control which uses both actuators.

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Authors and Affiliations

Jens Jungblut

e-mail:

ORCID:

Daniel Franz

Christian Fischer

e-mail:

ORCID:

Stephan Rinderknecht

e-mail:

ORCID:

Institute for Mechatronic Systems, Technical University Darmstadt, 64287, Germany

5 Turbine wheel reduced modal model for self-excited vibration suppression by inter-blade dry-friction damping

Luděk Pešek , Pavel Šnábl , Chandra Shekhar Prasad

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e148250 | DOI: 10.24425/bpasts.2023.148250

Keywords: blade dynamics travelling waves flutter dry-friction damping model reduction Van der Pol

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Abstract

A new approach to calculations based on the modal synthesis method is proposed for the evaluation of structural and dry-friction damping effects on self-excited vibrations due to aeroelastic instability in bladed turbine wheels. The method described herein is used to study dry-friction damping of self-excited vibration of an industrial turbine wheel with 66 blades. For evaluating damping effects, the blade couplings are applied to this particular turbine wheel. Therefore, neighbouring blades are interconnected by rigid arms that are fixed on one side to one blade and are in frictional contact on their free side with the other blade. Due to relatively normal motions in contacts, the prescribed contact forces vary over time. The aerodynamic excitation arises from the spatially periodical flow of steam through the stator blade cascade. In this paper, we attempt to model flow-induced instabilities with the Van der Pol model linked to relative motion between neighbouring blades. The proposed modal synthesis method as ROM is a computationally efficient solution allowing substantial parametrization. The effect of the angles of contact surfaces on the wheel dynamics and on the level of the self-excitation suppression will be discussed herein.

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Authors and Affiliations

Luděk Pešek

e-mail:

ORCID:

Pavel Šnábl

e-mail:

ORCID:

Chandra Shekhar Prasad

Institute of Thermomechanics of the CAS, v. v. i., Dolejškova 1402/5, 182 00 Praha 8, Czech Republic

6 Thermo-elasto-hydrodynamic analysis of bump-type air foil thrust bearings considering misalignment

Markus Eickhoff , Johannis Triebwasser , Bernhard Schweizer

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147917 | DOI: 10.24425/bpasts.2023.147917

Keywords: air foil thrust bearing simulation misalignment

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Abstract

In this study, a multi-pad bump-type foil thrust bearing with a taper-land height profile is investigated. A detailed thermo-elastohydrodynamic (TEHD) finite element (FE) model is used comprising all bearing pads instead of only a single pad. Although the single-pad reduction approach is commonly applied, it can not accurately account for the different temperatures, loads, and power losses for individual pads in the case of misalignment. The model accounts for the deformations of the foils on each pad via a Reissner-Mindlin-type shell model. Deformations of the rotor are calculated via the Navier-Lamé equations with thermoelastic stresses and centrifugal effects. The temperature of the top foil and the rotor are calculated with the use of heat diffusion equations. The temperature of each lubricating air film is obtained through a 3D energy equation. Film pressures are calculated with the 2D compressible Reynolds equation. Moreover, the surrounding of the bearing and runner disk is part of the thermodynamic model. Results indicate that the thermal bending of the runner disk as well as top foil sagging are key factors in performance reduction. Due to the bump-type understructure, the top foil sagging effect is observed in simulation results. The study at hand showcases the influence of misalignment between the rotor and the bearing on the bearing performance.

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Authors and Affiliations

Markus Eickhoff

e-mail:

ORCID:

Johannis Triebwasser

Bernhard Schweizer

Institute of Applied Dynamics, Technical University of Darmstadt, Germany

7 Experimental identification of the force and moment characteristic of symmetrically and non-symmetrically profiled annular seals

Maximilian M. G. Kuhr , Peter F. Pelz

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147062 | DOI: 10.24425/bpasts.2023.147062

Keywords: dynamic force and moment characteristics annular seals damper seals experiments

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Abstract

In modern turbomachinery, the performance and reliability is often limited by shaft vibrations induced by fluid film forces and moments of (i) plain or (ii) profiled annular seals. Therefore, these narrow annuli are mainly responsible for the overall system behaviour, i.e. safe operation and maintenance intervals. However, many studies focus only on the characteristics from the forces due to the translational motion, although the influence of the rotordynamic tilt and moment coefficients is well known. Therefore, these additional coefficients are much less researched. Especially, for profiled seals, the availability of reliable experimental data for validation purpose is rare. To overcome this fact, a test rig is operated at the Chair of Fluid Systems at the Technische Universität Darmstadt. The generic experiments presented here investigate the force and moment characteristic of plain, symmetrically profiled and non-symmetrically profiled annular seals within the relevant parameter range for turbulent flows in pumps. The investigations focus on the influence of the annulus length as well as the pressure difference across the annulus.

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Authors and Affiliations

Maximilian M. G. Kuhr

e-mail:

ORCID:

Peter F. Pelz

e-mail:

ORCID:

Chair of Fluid Systems, Technische Universität Darmstadt, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany

8 Vibration reduction on circular saw blades with vibroacoustic metamaterials

Sebastian Rieß , William Kaal , Sven Herold

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147921 | DOI: 10.24425/bpasts.2023.147921

Keywords: circular saw blade vibroacoustic metamaterial

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Abstract

The presented work focuses on the experimental investigation of a vibroacoustic metamaterial integrated into a spinning circular saw blade. Vibroacoustic metamaterials are a novel technology for broadband vibration reduction. Built from an array of local resonators, a broadband vibration reduction characteristic in the frequency domain (a so-called stop band) can be achieved. A design of a vibroacoustic metamaterial suitable for integration into a circular saw blade is developed and a numerical stop band prediction is performed. The resonators of the vibroacoustic metamaterial are integrated into the saw blade with a water jet cutting machine to create slots, forming flaps that are free to oscillate. The structural dynamic behavior of the saw blade with integrated vibroacoustic metamaterial is experimentally investigated on a rotor dynamic test bench and compared to that of a standard saw blade. The saw blades are excited by an automatic impulse hammer and the resulting out-of-plane vibrations are measured with a laser vibrometer at two different radii. Measurements are conducted at different rotational speeds up to 1800 rpm. Up to rotational speeds of 1000 rpm a stop band characteristic in the frequency range of 1900–2500 Hz is observed.

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Authors and Affiliations

Sebastian Rieß

e-mail:

ORCID:

William Kaal

e-mail:

ORCID:

Sven Herold

e-mail:

ORCID:

Fraunhofer Institute for Structural Durability and System Reliability LBF, 64298, Darmstadt, Germany

9 Efficient rotordynamic simulations with semi-analytical computation of hydrodynamic forces

Simon Pfeil , Fabian Duvigneau , Elmar Woschke

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e148252 | DOI: 10.24425/bpasts.2023.148252

Keywords: SBFEM Reynolds equation hydrodynamic bearings rotordynamics

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Abstract

A common problem in transient rotordynamic simulations is the numerical effort necessary for the computation of hydrodynamic bearing forces. Due to the nonlinear interaction between the rotordynamic and hydrodynamic systems, an adequate prediction of shaft oscillations requires a solution of the Reynolds equation at every time step. Since closed-form analytical solutions are only known for highly simplified models, numerical methods or look-up table techniques are usually employed. Numerical solutions provide excellent accuracy and allow a consideration of various physical influences that may affect the pressure generation in the bearing (e.g., cavitation or shaft tilting), but they are computationally expensive. Look-up tables are less universal because the interpolation effort and the database size increase significantly with every considered physical effect that introduces additional independent variables. In recent studies, the Reynolds equation was solved semianalytically by means of the scaled boundary finite element method (SBFEM). Compared to the finite element method (FEM), this solution is relatively fast if a small discretization error is desired or if the slenderness ratio of the bearing is large. The accuracy and efficiency of this approach, which have already been investigated for single calls of the Reynolds equation, are now examined in the context of rotordynamic simulations. For comparison of the simulation results and the computational effort, two numerical reference solutions based on the FEM and the finite volume method (FVM) are also analyzed.

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Authors and Affiliations

Simon Pfeil

e-mail:

ORCID:

Fabian Duvigneau

e-mail:

ORCID:

Elmar Woschke

e-mail:

ORCID:

Otto von Guericke University, Institute of Mechanics, Universitätspl. 2, 39106 Magdeburg, Germany

10 Numerical investigation of rotor-bearing systems with fractional derivative material damping models

Gregor Überwimmer , Georg Quinz , Michael Klanner , Katrin Ellermann

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e148610 | DOI: 10.24425/bpasts.2023.148610

Keywords: Numerical Assembly Technique rotor-bearing system steady-state harmonic vibration unbalance response fractional derivative damping model

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Abstract

The increasing demand for high-speed rotor-bearing systems results in the application of complex materials, which allow for a better control of the vibrational characteristics. This paper presents a model of a rotor including viscoelastic materials and valid up to high spin speeds. Regarding the destabilization of rotor-bearing systems, two main effects have to be investigated, which are strongly related to the associated internal and external damping of the rotor. For this reason, the internal material damping is modeled using fractional time derivatives, which can represent a large class of viscoelastic materials over a wide frequency range. In this paper, the Numerical Assembly Technique (NAT) is extended for the rotating viscoelastic Timoshenko beam with fractional derivative damping. An efficient and accurate simulation of the proposed rotor-bearing model is achieved. Several numerical examples are presented and the influence of internal damping on the rotor-bearing system is investigated and compared to classical damping models.

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Authors and Affiliations

Gregor Überwimmer

e-mail:

ORCID:

Georg Quinz

Michael Klanner

e-mail:

ORCID:

Katrin Ellermann

Graz University of Technology, Institute of Mechanics, Kopernikusgasse 24/IV, 8010 Graz, Austria

11 Data-driven virtual sensor for powertrains based on transfer learning

Aku Karhinen , Aleksanteri Hamalainen , Mikael Manngard , Jesse Miettinen , Raine Viitala

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147061 | DOI: 10.24425/bpasts.2023.147061

Keywords: powertrain torsional vibration long short-term memory virtual sensor transfer learning

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Abstract

Variation in powertrain parameters caused by dimensioning, manufacturing and assembly inaccuracies may prevent model-based virtual sensors from representing physical powertrains accurately. Data-driven virtual sensors employing machine learning models offer a solution for including variations in the powertrain parameters. These variations can be efficiently included in the training of the virtual sensor through simulation. The trained model can then be theoretically applied to real systems via transfer learning, allowing a data-driven virtual sensor to be trained without the notoriously labour-intensive step of gathering data from a real powertrain. This research presents a training procedure for a data-driven virtual sensor. The virtual sensor was made for a powertrain consisting of multiple shafts, couplings and gears. The training procedure generalizes the virtual sensor for a single powertrain with variations corresponding to the aforementioned inaccuracies. The training procedure includes parameter randomization and random excitation. That is, the data-driven virtual sensor was trained using data from multiple different powertrain instances, representing roughly the same powertrain. The virtual sensor trained using multiple instances of a simulated powertrain was accurate at estimating rotating speeds and torque of the loaded shaft of multiple simulated test powertrains. The estimates were computed from the rotating speeds and torque at the motor shaft of the powertrain. This research gives excellent grounds for further studies towards simulation-to-reality transfer learning, in which a virtual sensor is trained with simulated data and then applied to a real system.

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Authors and Affiliations

Aku Karhinen

e-mail:

ORCID:

Aleksanteri Hamalainen

Mikael Manngard

Jesse Miettinen

Raine Viitala

Department of Mechanical Engineering, Aalto University, 02150, Espoo, Finland
Novia University of Applied Sciences, Juhana Herttuan puistokatu 21, 20100 Turku, Finland

12 Controlling bifurcations in high-speed rotors utilizing active gas foil bearings

Anastasios Papadopoulos , Ioannis Gavalas , Athanasios Chasalevris

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e146796 | DOI: 10.24425/bpasts.2023.146796

Keywords: bifurcation control Hopf bifurcation active gas foil bearings high speed rotors nonlinear control

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Abstract

High-speed rotors on gas foil bearings (GFBs) are applications of increasing interest due to their potential to increase the power-toweight ratio in machines and also formulate oil-free design solutions. The gas lubrication principles render lower (compared to oil) power loss and increase the threshold speed of instability in rotating systems. However, self-excited oscillations may still occur at circumferential speeds similar to those in oil-lubricated journal bearings. These oscillations are usually triggered through Hopf bifurcation of a fixed-point equilibrium (balanced rotor) or secondary Hopf bifurcation of periodic limit cycles (unbalanced rotor). In this work, an active gas foil bearing (AGFB) is presented as a novel configuration including several piezoelectric actuators that shape the foil through feedback control. A finite element model for the thin foil mounted in some piezoelectric actuators (PZTs), is developed. Second, the gas-structure interaction is modelled through the Reynolds equation for compressible flow. A simple physical model of a rotating system consisting of a rigid rotor and two identical gas foil bearings is then defined, and the dynamic system is composed with its unique source of nonlinearity to be the impedance forces from the gas to the rotor and the foil. The third milestone includes a linear feedback control scheme to stabilize (pole placement) the dynamic system, linearized around a speed-dependent equilibrium (balanced rotor). Further to that, linear feedback control is applied in the dynamic system utilizing polynomial feedback functions in order to overcome the problem of instability.

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Authors and Affiliations

Anastasios Papadopoulos

Ioannis Gavalas

e-mail:

ORCID:

Athanasios Chasalevris

e-mail:

ORCID:

National Technical University of Athens, Athens, Greece

13 Research on improved sparrow search algorithm for PID controller parameter optimization

Mingfeng Zhang , Chuntian Xu , Deying Xu , Guoqiang Ma , Han Han , Xu Zong

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147344 | DOI: 10.24425/bpasts.2023.147344

Keywords: improved sparrow search algorithm PID controller parameter optimization

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Abstract

PID controllers are crucial for industrial control because of their simple structure and good robustness. In order to further improve the accuracy of PID controllers, this paper proposes an improved sparrow search algorithm (ISSA) to prevent the problem of the algorithm being prone to falling into the local optimum at the late stage of iteration. Based on the standard sparrow search algorithm, the position update formula and the step size control parameter are optimized to help quickly jump out of the local, and to obtain the optimal solution in the whole domain. Finally, to verify the accuracy and stability of the improved algorithm, nine standard test functions are first simulated. Then, the PID parameter optimization tests are finished with the chilled water and battery charging systems, where the lifting load and applying perturbation are carried out. Both the simulation and test results show that ISSA improves the convergence speed and accuracy, and performs better in terms of stability.

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Authors and Affiliations

Mingfeng Zhang

Chuntian Xu

e-mail:

ORCID:

Deying Xu

Guoqiang Ma

Han Han

Xu Zong

School of Mechanical Engineering and Automation, University of Science and Technology Liaoning, Anshan, Liaoning, China
College of Science – Computer Science, University of Arizona, Tucson, Arizona, USA
Angang Steel Co. LTD, Anshan Iron & Steel, Anshan, Liaoning, China

14 Improved efficient capsule network for Kuzushiji-MNIST benchmark dataset classification

Michał Bukowski , Izabella Antoniuk , Jarosław Kurek

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147338 | DOI: 10.24425/bpasts.2023.147338

Keywords: efficient capsule networks Kuzushiji-MNIST Kuzushiji-49 deep learning

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Abstract

In this paper, we present an improved efficient capsule network (CN) model for the classification of the Kuzushiji-MNIST and Kuzushiji-49 benchmark datasets. CNs are a promising approach in the field of deep learning, offering advantages such as robustness, better generalization, and a simpler network structure compared to traditional convolutional neural networks (CNNs). Proposed model, based on the Efficient CapsNet architecture, incorporates the self-attention routing mechanism, resulting in improved efficiency and reduced parameter count. The experiments conducted on the Kuzushiji-MNIST and Kuzushiji-49 datasets demonstrate that the model achieves competitive performance, ranking within the top ten solutions for both benchmarks. Despite using significantly fewer parameters compared to higher-rated competitors, presented model achieves comparable accuracy, with overall differences of only 0.91% and 1.97% for the Kuzushiji-MNIST and Kuzushiji- 49 datasets, respectively. Furthermore, the training time required to achieve these results is substantially reduced, enabling training on nonspecialized workstations. The proposed novelties of capsule architecture, including the integration of the self-attention mechanism and the efficient network structure, contribute to the improved efficiency and performance of presented model. These findings highlight the potential of CNs as a more efficient and effective approach for character classification tasks, with broader applications in various domains.

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Authors and Affiliations

Michał Bukowski

e-mail:

ORCID:

Izabella Antoniuk

e-mail:

ORCID:

Jarosław Kurek

e-mail:

ORCID:

Department of Artificial Intelligence, Institute of Information Technology, Warsaw University of Life Sciences, Nowoursynowska 159, Warsaw, 02-776, Poland

15 A hybrid model of heuristic algorithm and gradient descent to optimize neural networks

Amer Mirkhan , Numan Çelebi

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147924 | DOI: 10.24425/bpasts.2023.147924

Keywords: optimization heuristic algorithms neural networks dynamic population

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Abstract

Training a neural network can be a challenging task, particularly when working with complex models and large amounts of training data, as it consumes significant time and resources. This research proposes a hybrid model that combines population-based heuristic algorithms with traditional gradient-based techniques to enhance the training process. The proposed approach involves using a dynamic population-based heuristic algorithm to identify good initial values for the neural network weight vector. This is done as an alternative to the traditional technique of starting with random weights. After several cycles of distributing search agents across the search domain, the training process continues using a gradient-based technique that starts with the best initial weight vector identified by the heuristic algorithm. Experimental analysis confirms that exploring the search domain during the training process decreases the number of cycles needed for gradient descent to train a neural network. Furthermore, a dynamic population strategy is applied during the heuristic search, with objects added and removed dynamically based on their progress. This approach yields better results compared to traditional heuristic algorithms that use the same population members throughout the search process.

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Authors and Affiliations

Amer Mirkhan

Numan Çelebi

e-mail:

ORCID:

Sakarya University, Computer Engineering Department
Sakarya University, Information Systems Engineering Department

16 A deep learning method for hard-hat-wearing detection based on head center localization

Bartosz Wójcik , Mateusz Żarski , Kamil Książek , Jarosław A. Miszczak , Mirosław J. Skibniewski

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147340 | DOI: 10.24425/bpasts.2023.147340

Keywords: hard hat personal protective equipment construction safety deep learning keypoint R-CNN

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Abstract

In recent years, a lot of attention has been paid to deep learning methods in the context of vision-based construction site safety systems. However, there is still more to be done to establish the relationship between supervised construction workers and their essential personal protective equipment, like hard hats. A deep learning method combining object detection, head center localization, and simple rule-based reasoning is proposed in this article. In tests, this solution surpassed the previous methods based on the relative bounding box position of different instances and direct detection of hard hat wearers and non-wearers. Achieving MS COCO style overall AP of 67.5% compared to 66.4% and 66.3% achieved by the approaches mentioned above, with class-specific AP for hard hat non-wearers of 64.1% compared to 63.0% and 60.3%. The results show that using deep learning methods with a humanly interpretable rule-based algorithm is better suited for detecting hard hat non-wearers.

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Authors and Affiliations

Bartosz Wójcik

e-mail:

ORCID:

Mateusz Żarski

e-mail:

ORCID:

Kamil Książek

Jarosław A. Miszczak

Mirosław J. Skibniewski

1 2

Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, 44-100 Gliwice, Poland
A. James Clark School of Engineering, University of Maryland, College Park, MD 20742-3021, USA

17 S-modeS-model for project cost management in value engineering for construction companies

Yang Yang , Wanxin Xiao , Margarita Lyshenko , Yang Zhang

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e146617 | DOI: 10.24425/bpasts.2023.146617

Keywords: cash flow construction management cost control engineering construction scenario modelling value management

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Abstract

Today’s fast-changing environment for construction companies requires rapid responses and adaptation of their projects. Despite the multitude of tools applied for project cost management in engineering and construction companies, there is a need to form comprehensive solutions. The purpose of the study is to form a methodological approach to project cost management in the field of engineering construction based on alternative models to diagnose the development, assessment and selection of functional areas and content of cost management in the construction project, which allows one to increase adaptability and flexibility in the process of its implementation. The basis of research methodology is modeling, which allows one to adjust the economic and financial flows based on three S-curves, one for each component of the total cost of the work: direct costs, indirect costs and reserves. These curves include the direct cost curve for the main purchasing packages as well. This brings financial flows closer to reality because it is possible to adjust the S-curves according to the behavior of each subsystem. The contribution of the study is the proposed approach of integrating concepts related to the coordination and development of project design and production management (lean construction), forming a “3D model of management”, in a broad and comprehensive management system. It assumes a comprehensive and complete way to manage civil engineering projects. The proposed methodological approach can make a significant contribution to the preparation of forecasts and estimates by planners and controllers in the context of construction projects.

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Authors and Affiliations

Yang Yang

1 2

e-mail:

ORCID:

Wanxin Xiao

2 3

Margarita Lyshenko

Yang Zhang

2 4

Department of Construction Engineering, Xinxiang Vocational and Technical College, Xinxiang, China
Faculty of Economics and Management, Sumy National Agrarian University, Sumy, Ukraine
Funding Center, Education Bureau of Hongqi District, Xinxiang City, China
Personnel Department, Henan Expressway Monitoring Toll Communication Network Service Co. Ltd., Zhengzhou, China

18 Preliminary analysis of catenoid chimney cooling towers

Maciej Wiśniowski , Robert Walentyński , Dawid Cornik

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147341 | DOI: 10.24425/bpasts.2023.147341

Keywords: catenoid shell cooling tower FEM CFD

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Abstract

Optimization plays an important role in scientific and engineering research. This paper presents the effects of using the catenoidal shape to design the structure of a chimney cooling tower. The paper compares some geometrical variations of the catenoid with the reference existing hyperboloidal structure. It also compares internal forces, deformation and stability of the catenoidal structure. The comparison shows some predominance of the catenoid over the popular hyperboloid structure of the shell. The paper attempts to find an optimal shape of the cooling tower in order to reduce the amount of material and labor. The paper utilizes engineering tools and the designing process for chimney cooling towers.

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Authors and Affiliations

Maciej Wiśniowski

e-mail:

ORCID:

Robert Walentyński

e-mail:

ORCID:

Dawid Cornik

e-mail:

ORCID:

Faculty of Civil Engineering, Department of Mechanics and Bridges, ul. Akademicka 5, 44-100 Gliwice, Poland

19 Comparison of the effects of anthropogenic seismic events and natural earthquakes on buried infrastructure network components

Janusz Rusek , Leszek Słowik , Krzysztof Tajduś

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147347 | DOI: 10.24425/bpasts.2023.147347

Keywords: pipeline dynamic seismic mining

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Abstract

Mining tremors may have an impact on the safety risk of steel pipelines through their effects. It is therefore important to quantify the impact of a high-energy mining tremor in terms of strength. In addition, a comparison of the results obtained with the effect of a seismic tremor can illustrate the scale of such a hazard. Recently, this has been a very frequently raised issue in the area of surface protection against negative mining impacts and the protection of post-mining areas. Ensuring safe use is particularly important for gas transmission elements. This paper presents the results of a comparative analysis of the impact of mining tremors and seismic impacts on a specimen steel pipeline segment. The analyzed pipeline is located in the eastern part of Poland in the area of paraseismic impacts of the LGCD (Legnica-Glogow Copper District) mine. For this purpose, an analytical approach was used to assess the impact of seismic wave propagation on underground linear infrastructure facilities. Accelerogram records for the 02-06-2023 seismic tremor from Turkey and the mining tremor for 11-25-2020 were used. In the case of the design of underground pipelines, the cross-section of the element for which measures describing wall stress and the ovalization of the cross-section are determined is usually considered. In the situation of the influence of seismic wave propagation or so-called permanent ground deformation, the response of the pipeline in the longitudinal direction is analyzed. As a final result, longitudinal strains transferred to the pipeline as a consequence of the propagating seismic wave and mining tremor were determined. The absolute difference between the deformations in the ground and along the length of the pipeline was determined. This type of analysis has not been carried out before and provides new insights into the topic of paraseismic impacts on the scale of their interaction with natural earthquakes. Mining tremor data was obtained from the mine’s seismological department. The seismic tremor data, on the other hand, was downloaded via the publicly available ESM (Engineering Strong- Motion Database).

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Authors and Affiliations

Janusz Rusek

e-mail:

ORCID:

Leszek Słowik

e-mail:

ORCID:

Krzysztof Tajduś

e-mail:

ORCID:

AGH University of Krakow al. Adama Mickiewicza 30, 30-059 Krakow, Poland
ITB Building Research Institute ul. Filtrowa 1, 00-611 Warsaw, Poland

20 Transformations of the matrices of linear systems to their canonical form with desired eigenvalues

Tadeusz Kaczorek

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147342 | DOI: 10.24425/bpasts.2023.147342

Keywords: canonical form desired eigenvalue linear system transformation

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Abstract

A new approach to the transformations of the matrices of linear continuous-time systems to their canonical forms with desired eigenvalues is proposed. Conditions for the existence of solutions to the problems were given and illustrated by simple numerical examples.

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Authors and Affiliations

Tadeusz Kaczorek

e-mail: t.kaczorek@pb.edu.pl

ORCID:

Bialystok University of Technology, Białystok, Poland

21 An autonomous system for identifying and tracking characters using neural networks

Sebastian Słomiński , Magdalena Sobaszek

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147923 | DOI: 10.24425/bpasts.2023.147923

Keywords: markerless tracking deep learning detection dynamic lighting pose identification

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Abstract

For the proper operation of intelligent lighting, the precise detection of a human silhouette on the scene is necessary. Correctly adjusting the light beam divergence requires locating the detected figure in virtual three-dimensional coordinates in real time. The market is currently dominated by the markers systems. This paper is focused on the advanced solution of the markerless system of identifying and tracking characters based on deep learning methods. Analyses of the selected pose detection, holistic detection (including BalzePose and MoveNet models), and body segmentation (BlazePose and tfbodypix) algorithms are presented. The BlazePose model was implemented for both pose tracking and body segmentation in the markerless dynamic lighting and mapping system. This article presents the results of the accuracy analysis of matching the displayed content to a moving silhouette. An assessment of the illumination precision was done as the function of the movement speed for the system with and without delay compensation.

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Authors and Affiliations

Sebastian Słomiński

e-mail:

ORCID:

Magdalena Sobaszek

e-mail:

ORCID:

Warsaw University of Technology, Electrical Power Engineering Institute, Lighting Technology Division, Poland

22 Influence of replacing discharge lamps with LED sources in outdoor lighting installations on astronomical observations

Przemysław Tabaka , Sylwester Kołomański

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147915 | DOI: 10.24425/bpasts.2023.147915

Keywords: outdoor lighting LED sources light pollution astronomical observations Starlight Contamination Degree

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Abstract

Light pollution has a detrimental effect on astronomy. Artificial light emitted from outdoor lighting increases the brightness of the night sky, making it difficult to observe astronomical objects. The spectral power distribution of artificial light sources is one of the key factors determining how much the night sky is deteriorated by light pollution. The ongoing replacement of discharge lamps with LED sources may have a major impact on astronomy because LED spectra usually cover the entire visible radiation range. This paper provides an analysis of the impact of LED sources with correlated color temperature in the range from 1000 K to approximately 10 000 K on visual and instrumental astronomical observations. For each analyzed artificial source, the Starlight Contamination Degree (SCD) index, i.e. a quantity that allows for quick evaluation of the impact of the sources on the night sky, is calculated. The reflection of artificial light from different ground surfaces and its scattering in the atmosphere was included in the calculation of the SCD index. LED lamps with very low values of correlated color temperature (CCT) and color rendering index (CRI) were found to possibly have a similar or even smaller impact on astronomical observations than sodium discharge lamps. Moreover, professional astronomical observations are more affected by LED lamps than visual observations, even for lamps with the lowest CCT and CRI. Thus, additional measures (e.g. reducing lumen output) should be applied to protect observational conditions. The results of the study help to assess which LED lamps can be used, and which should be avoided in the protection zones around astronomical observing sites.

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Authors and Affiliations

Przemysław Tabaka

e-mail:

ORCID:

Sylwester Kołomański

Institute of Electrical Power Engineering, Lodz University of Technology, Lodz, Poland
Astronomical Institute, University of Wrocław, Wrocław, Poland

23 Energy efficiency indicators in road lighting: critical evaluation in a case study

Sophia Heredia , Oscar Ulises Preciado , Alberto José Cabello , Eduardo Roberto Manzano

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147916 | DOI: 10.24425/bpasts.2023.147916

Keywords: energy efficiency energy efficiency indicator lighting standards public lighting road lighting

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Abstract

Road lighting is a fundamental public service for the safety of pedestrians and drivers. Due to the global energy crisis and climate change, energy conservation has become a priority in any country. Road lighting should provide the required quality and quantity of illumination in the most efficient manner possible. In this work, a study of lighting conditions was carried out in an Argentinian city, and energy efficiency was evaluated based on three methods. The results and conclusions of the work provide an objective critique of the advantages and disadvantages of applying each method to measure the efficiency of an installation.

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Authors and Affiliations

Sophia Heredia

1 2

e-mail:

ORCID:

Oscar Ulises Preciado

1 2

e-mail:

ORCID:

Alberto José Cabello

1 2

Eduardo Roberto Manzano

1 2

e-mail:

ORCID:

Departamento de Luminotecnia, Luz y Visión, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán (DLLyV-FACET-UNT). Av. Independencia 1800, 4000 Tucumán, Argentina
Instituto de Investigación en Luz, Ambiente y Visión (ILAV-UNT-CONICET) Av. Independencia 1800, 4000 Tucumán, Argentina

24 Polyurethane shape memory polymer: structure characterization and estimation of energy storage and dissipation during the tension process

Maria Staszczak , Arkadiusz Gradys , Karol Golasiński , Elżbieta A. Pieczyska

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147343 | DOI: 10.24425/bpasts.2023.147343

Keywords: shape memory polymer infrared camera thermomechanical couplings energy storage and dissipation tension test

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Abstract

Shape memory polymers (SMP) are new multifunctional materials raising increasing interest in various functional applications. Among them, polyurethane shape memory polymers (PU-SMP) are particularly attractive due to their combination of shape memory, high strength and biocompatible properties. Developing new applications for PU-SMP requires comprehensive research on their characteristics. This work involved investigating the structure and mechanical behavior as well as characterizing the energy storage and dissipation of a thermoplastic PU-SMP with a glass transition temperature (Tg) of 25_C during tensile loading-unloading. The process of energy storage and dissipation in the PU-SMP was investigated based on the stress-strain curves recorded by a quasi-static testing machine and the temperature changes, accompanying the deformation process, obtained by using a fast and sensitive infrared camera. The results showed that the thermomechanical behavior of the examined PU-SMP depends significantly on the strain rate. At a higher strain rate, there are higher stress and related temperature changes, which lead to greater energy dissipation. However, the energy storage values estimated during the deformation process turned out to be not significant, indicating that the work supplied to the PU-SMP structure during loading is mainly converted into heat. It should also be noted that the structural investigation revealed no crystalline phase in the investigated PU-SMP.

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Authors and Affiliations

Maria Staszczak

e-mail:

ORCID:

Arkadiusz Gradys

e-mail:

ORCID:

Karol Golasiński

e-mail:

ORCID:

Elżbieta A. Pieczyska

e-mail:

ORCID:

Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawi´nskiego 5B, 02-106 Warsaw, Poland
Multidisciplinary Research Center, Cardinal Stefan Wyszy´ nski University in Warsaw, Dewajtis 5, 01-815 Warsaw, Poland

25 Kinovea analysis of high-speed video recording to determine kinematics of double pendulum in the long time scale

Jerzy Wojewoda

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 6 | e147918 | DOI: 10.24425/bpasts.2023.147918

Keywords: angular position rotary speed video analysis video tracking

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Abstract

Measurement of position and velocity of rotating objects relies on installation of additional devices, which can significantly change their dynamic properties. Non-contact methods appear not to have the above-mentioned drawback. To determine the angular kinematics, a video measurement technique stands as a non-contact alternative. The rotational motion can be recorded with a high-speed camera and then analyzed with free and open-source tracking software which allows one to detect and digitize positions of chosen markers and then to calculate angular positions of selected elements. Differentiation process determines rotary speed values. Analysis of long-term dynamical behavior by recording data visualized as position maps which possess half of the information usually stored in the well-known Poincaré maps is proposed.

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