Wyniki wyszukiwania - BazTech

1

Optymalizacja bezszczotkowego silnika pądu stałego do napędów pojazdów elektrycznych

Knypiński Łukasz, Kasprzak Kacper, Idziak Paweł

Przegląd Elektrotechniczny

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2025

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R. 101, nr 10

63--68

PL

W artykule przedstawiono algorytm wspomagający proces projektowania bezszczotkowych silników prądu stałego (BLDC) z zewnętrznym wirnikiem. Opracowano uniwersalny model silnika BLDC. W procedurze optymalizacyjnej zastosowano algorytm optymalizacji wielorybów. Opracowano autorskie oprogramowanie składające się z dwóch modułów: procedury optymalizacyjnej oraz modelu projektowanego silnika. Projektowany silnik opisano przy wykorzystaniu pięciu zmiennych decyzyjnych. Rozpatrywano dwa zadania optymalizacyjne. Przedstawiono i omówiono wybrane wyniki obliczeń optymalizacyjnych.

EN

The paper presents optimization algorithm for support designing process of a brushless DC (BLDC) motor with an outer-rotor for an electric bike. The universal model of the BLDC motor was developed. To optimization, the whale optimization algorithm was employed. Two module optimization script combine optimization procedure with model of designed BLDC motor. The designed motor was described by five design variables. Two optimization problems are solved. Selected optimization results was selected and discussed.

2

Ocena istniejących konstrukcji budowlanych według nowej normy Eurokod 1990-2

Halicka Anna

Przegląd Budowlany

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2025

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R. 96, nr 4

44--51

PL

W pracy przedstawiono reguły postępowania przy ocenie istniejących konstrukcji budowlanych zawarte w nowej normie Eurokod 1990-2. Przedstawiono normowy algorytm postępowania. Omówiono metody ilościowe oceny bezpieczeństwa konstrukcji – probabilistyczną, półprobabilityczną (metodę współczynników częściowych) ocenę ryzyka, a także metodę oceny jakościowej. Omawiając metodę współczynników częściowych dodano informacje dotyczące konstrukcji z betonu podane w nowelizacji Eurokodu 1992-1.

EN

The paper presents the rules of for the assessment of existing building structures included in the new Eurocode 1990-2 standard. A standard procedure algorithm is presented. Quantitative methods for assessing the safety of structures are discussed – probabilistic, semi-probable (partial coefficient method) risk assessment, as well as the qualitative assessment method. When discussing the partial coefficient method, information regarding concrete structures given in the Eurocode 1992-1 amendment was added.

3

Model and analysis of rope winch operation in underground rail transport

Krauze Krzysztof, Mucha Kamil, Wydro Tomasz, Klempka Ryszard

Archives of Mining Sciences

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2025

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Vol. 70, no. 3

377--386

EN

The primary means of rail transport in inclined workings up to 45° are typically single- or double-drum rope winches. These winches are part of a transport system consisting of the winch itself, a rope with a diameter d and length Ll, a track system, and a return drum with a rope tensioning mechanism. A fundamental challenge in employing winches in a given working is accounting for their operational conditions, which include the route length Lu, its inclination αu, and the value of the hauled mass (weight) Gm, given a specified load transport velocity vpł. These factors influence the drive load parameters, such as the winding rope force FC, unwinding rope force FS, and drive motor power Np. Manufacturers of these devices provide their structural (Lumax), kinematic (vpj), and energy-related (Np) parameters. However, it is the responsibility of the prospective user to assess the suitability of a specific winch for the conditions present in their transport excavation. To address this need, an analytical model, algorithm, and computer program have been developed to dynamically determine the required parameters while considering the winch’s operating conditions.

4

An analytical model for the tool center point placement in Robotic Roller Forming

Stewens Thomas, Liu Yi, Wang Ling, Min Junying

Computer Methods in Materials Science

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2024

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Vol. 24, No. 2

39--48

EN

Robotic Roller Forming (RRF) is a novel process using an articulated robotic manipulator that can bend Ultra-High Strength materials into thin-walled profiles. For high strength or difficult-to-form sheet materials, a laser can be employed to synchronously heat and soften the local material during RRF. The aim of RRF is to establish itself as a highly flexible process for rapid prototyping as well as for small batch production. However, in finished parts formed with different materials, a new defect that shapes the profile like that of a hook was observed. To overcome this defect and to improve the adaptability of the process, a new analytical model is suggested for the automatic calculation of the tool center point based on the given process parameters. The model was compared to the previous state, where the hook defect was noticeably reduced. Additionally, the control of the bend radius was studied, and the resulting bend radius diverged from the target radius by 0.04 mm (2.45%). Further, when examining the reproducibility, the same bend angles could be achieved as in previous experiments using the constant laser power density. Finally, the development of the bend allowance was studied in various experiments. The analytical model for RRF is a promising method for calculating tool placement and controlling the bend radius in a freeform environment.

5

Analytical study of frictional interaction of elastic cleaning pig with pipeline wall

Stetsiuk S.M., Shatskyi I.P., Doroshenko Ya.V., Velychkovych A.S.

Archives of Materials Science and Engineering

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2024

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Vol. 129, nr 2

67--76

EN

Purpose: Cleaning pigs made of highly elastic materials are used to remove contaminants from industrial gas pipelines. To ensure the movement of the pig in normal operation and narrow sections of the pipeline, it is necessary to generate the required gas pressure in the pig space. The study aims to establish the analytical conditions for the movement of a deformable pig in a cylindrical channel without stopping. Design/methodology/approach: A one-dimensional quasi-static model has been developed to analyse the frictional interaction of a moving deformable rod with a cylindrical pipe wall under conditions of uniform radial tightness. The normal contact is assumed to be dense, with no interfacial gas flow along the pig. Findings: Based on the solution of the formulated contact problem, the influence of frontal resistance, tension, friction, modulus of elasticity of the material and geometric dimensions of the rod on its stress state and on the value of pressure behind the pig required for the pig to pass through the pipeline without stopping is investigated. It is shown that an increase in the value of each factor leads to an increase in the driving gas pressure in the space behind the pig. Research limitations/implications: In the future, developing the proposed approach for the analytical modelling of pig motion in a pipe with variable narrowing is advisable. Practical implications: Recommendations for the design of deformable pigs for efficient gas pipeline cleaning are given. Originality/value: In analytical form, the dependences of the driving pressure on the key geometric and mechanical parameters of the process were found.

6

Modeling of air velocity in a fluid transported through a pipeline

Dmytriv Vasyl, Dmytriv Ihor, Horodetskyy Ivan, Wilk Andrzej, Hyla Pawel

Archives of Engineering Knowledge

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2024

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T. 10, Nr 1

100-108

EN

The article considers the movement of liquid with an air bubbles along a finite pipeline. Taking into account the Stokes equation, the Newtonian frictional stress and the Reynolds equation, a differential equation for the change in the velocity of an air bubble in a pipeline that transports a liquid at a given velocity speed is derived. It is assumed that the pipeline has no connection with the atmosphere. The analytical solution of the differential equation of the air bubble velocity in the moving fluid of the pipeline using the exponential integral is given. A fluid with dynamic viscosity of  = 1.79 10-3, Pas and density of ρp = 1027.3, kg/m3 was used for modeling. The angle of inclination of the pipeline was 45 degrees, the velocity of the liquid flow in the pipeline was taken as 0.1, 1.0, 2.0 and 5.0 m/s. The total length of the pipeline was H = 2 m. The air bubble was taken in the form of a sphere with an initial radius of 1, 5, and 10 mm. Air was blown into the fluid flow. When an air bubble enters the pipeline, its initial velocity corresponds to the velocity of the fluid flow. The diameter of the air bubble has almost no effect on its velocity speed. Аналіз Analysis of the velocity simulation results shows that as the velocity of the fluid increases, the velocity of the air bubble increases. The nature of the change of the air bubble velocity depending on the fluid velocity shows that there is a condition when the fluid velocity and the air bubble velocity will be equal. As the fluid velocity increases, the bubble velocity difference between the air entry point and the air exit point decreases. The decrease in the velocity difference is caused by the pressure force on the surface of the air bubble, which is caused by the velocity of the fluid and the air bubble itself. As the dynamic viscosity of the fluid increases, the air bubble velocity decreases. The developed dependence describes the physical process of the flow of Newtonian fluids and gases in the pipeline.

7

Design of a six-phase surface mounted permanent magnet synchronous motor with application to electric trucks

Vuong Dang Quoc, Cong Trinh Truong

Archives of Electrical Engineering

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2024

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Vol. 73, nr 3

721--741

EN

As we have known, permanent magnet synchronous motors (PMSMs) have garnered widespread interest across various industrial applications thanks to their advantages such as high efficiency, reliable performance, simple structure, and adaptability to various shapes and sizes. Due to characteristics of the high torque and low speed, the PMSMs make particularly well-suited for traction applications such as trucks, ship propulsion, mining, and more. In this context, a combination of the analytical method and finite element method (FEM) is proposed for designing and simulating a six-phase surface-mounted PMSM. Firstly, a model of the six-phase PMSM is analytically design to make required/main dimensions. The FEM is then applied to analyse and verify electromagnetic parameters such as of the current waveform, back electromagnetic force (EMF), magnetic flux density in the air gap, flux linkage, torque, cogging torque, torque ripple and harmonic components. Via the obtained results, the research will give a contribution of valuable insights for optimizing the design, performance and reliability for this motor in diverse industrial applications.

8

Influence of Gear Eccentricity with Non-Parallel Axis on the Dynamic Behaviour of a Gear Unit Using a Gear Slice Model with 26 Degrees of Freedom

Jedliński Łukasz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 2

88--102

EN

This study investigates the problems of eccentricity and backlash using an analytical spur gear model with 26 degrees of freedom (DOF). Previous studies have only investigated the case of eccentricity with a parallel shift of the axis of rotation of the gear relative to its geometric axis of symmetry. This study presents a novel method for determining the radius of eccentricity and its angular position at any distance from the bearing support, in which the axis of rotation and the geometric axis of symmetry of the gear are non-parallel. The effect of gear motion in the line of action (LOA) and off-line of action (OLOA) directions on backlash is precisely determined, despite the fact that most studies usually ignore gear displacement along the OLOA direction. Numerical simulations are performed to determine the effect of eccentricity on backlash, and their results confirm that the proposed method for determining the radius of eccentricity for any eccentricity type is correct. A gear slice model is used for dynamic analysis. Results show that the type of eccentricity has a significant effect on the gear dynamics and that eccentricity analyses have to include other cases than merely eccentricity with parallel axes of gears.

9

SPAD timing jitter modeling using Fourier series

Eyvazi Kaveh, Karami Mohammad Azim

Optica Applicata

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2023

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Vol. 53, nr 2

239--248

EN

In this paper, a simple analytical model for the Gaussian’s peak response part of the timing jitter of single photon avalanche diodes (SPADs) is proposed using Fourier series in the multiplication time calculation. The multiplication time characterizes avalanche multiplication process speed in which low multiplication time suggests a swifter response time and a higher avalanche speed. This paper presents an analytical solution which results in a more accurate multiplication time. The model is verified for SPADs implemented in 0.15 and 0.18 μm standard CMOS process, and the accuracy of the proposed analytical method in full-width at half-maximum (FWHM) calculation is improved by 25% and 5% with respect to the numerical model, respectively.

10

Recent developments in pullout behaviors and tensile properties of ultra-high-performance concrete reinforced with steel fiber

Wu Hansong, Zang Zhishu, Deng Shiyi, Shen Aiqin, Cai Yanxia, Ren Guiping, Pan Hongmei

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e216, 2023

EN

Ultra-high-performance concrete (UHPC) has gained significant attention as a construction material owing to its exceptional mechanical properties and durability. Steel fibers are widely utilized as a reinforcement material for UHPC. Achieving excellent bond and tensile performances is considered to be a predominant issue for the utilization of steel fiber reinforcement. This comprehensive review presents recent research progress on the bond and tensile properties of steel-fiber-reinforced UHPC. First, an overview of the experimental methods for evaluating pullout and tensile performance is provided. Subsequently, the factors influencing these properties are discussed in detail. The review then comprehensively examines several analytical models for steel-fiber-reinforced UHPC, ranging from traditional approaches to innovative methods such as artificial neural network models, genetic algorithms, deep learning methods, inverse analysis, and micromechanical damage models. Furthermore, the correlations between pullout behavior, tensile performance, and flexural strength are explored in detail. Finally, the review addresses essential considerations and summarizes various modification techniques for improving the pullout and tensile performances, including physical and chemical methods of modifying the steel fiber surface and UHPC matrix. This review serves as a valuable reference for researchers and engineers in relevant fields, promoting further research and application of steel fiber-reinforced UHPC.

11

Classifying Speech Acts in Political Communication: A Transformer-based Approach with Weak Supervision and Active Learning

Schmidt Klaus, Niekler Andreas, Kantner Cathleen, Burghardt Manuel

Annals of Computer Science and Information Systems

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2023

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Vol. 35

739--748

EN

We present a study on the automatic classification of speech acts in the domain of political communication, based on J. R. Searle's classification of illocutionary acts. Our research involves creating a dataset using the US State of the Union corpus and the UN General Debate corpus (UNGD) as data sources. To overcome limited labeled data, we employ a combination of weak supervision and active learning techniques for dataset creation and model training. Through various experiments, we investigate the influence of external and internal factors on speech act classification. In addition, we discuss the potential for further analysis of speech act usage, using the trained model on the UNGD corpus. The findings demonstrate the effectiveness of Transformer-based models for automatic speech act classification, highlight the benefits of weak supervision and active learning for dataset creation and model training, and underscore the potential for large-scale statistical analysis of speech act usage in the domain of political communication.

12

Analysis of the Impact of Data Augmentation on the Performance of Deep Learning Models in Multispectral Food Authenticity Identification

Zhang Yaru, Yilmaz Arif, Popa Mirela, Brewster Christopher

Annals of Computer Science and Information Systems

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2023

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Vol. 35

823--832

EN

Food authenticity is a significant concern in the meat industry, demanding effective detection methods. This study explores the use of multispectral imaging (MSI) and deep learning for meat adulteration detection. We evaluate different deep learning models using transfer learning and preprocessing techniques in a multi-level adulteration classification task. In addition, we propose a novel approach called one-band mixed augmentation for band selection in MSI data, which outperforms traditional reflectance-based feature selection and enhances model robustness. Furthermore, employing the nine-crop approach for dataset augmentation improved the accuracy from 0.63 to 0.74 for DenseNet201 model without transfer learning. This research contributes to advancing food safety assessment practices and provides insights into the application of deep learning for preventing food adulteration. The proposed one-band mixed augmentation approach offers a novel strategy for handling band selection challenges in MSI data analysis.

13

An Enhancement of Reinforcement Learning by Scheduling with Learning Effects

Rudek Radosław

Annals of Computer Science and Information Systems

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2023

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Vol. 35

689--697

EN

This paper present results, which reveal that approaches obtained for scheduling problems with learning effects can be successfully used to improve the quality of machine learning methods. It is illustrated by modelling some aspects of Q-learning agents as scheduling problems with the learning effect, and constructing sequencing and dispatching algorithms, which take into account the existence of learning. Their application to determine the sequence of tasks processed by Q-learning agents can visibly speed up their convergence to an optimal strategy. Furthermore, we show that a dispatch of tasks according to the longest processing time algorithm for parallel computing can be replaced by a more efficient procedure, if agents can learn. The numerical analysis reveals that our approach is efficient, robust and only marginally dependents on a learning model and an accurate approximation of task processing times.

14

Dyspersja hydrodynamiczna w procesie wypierania gazów w rdzeniach skalnych

Blicharski Jacek, Stopa Jerzy

Przemysł Chemiczny

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2022

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T. 101, nr 1

50--54

PL

Przedstawiono wyniki badań laboratoryjnych wypierania azotu metanem w rdzeniach skalnych. Zaprezentowano model matematyczny eksperymentu oraz wyznaczono wartości współczynników dyfuzji molekularnej i dyspersji mechanicznej. Zaobserwowano zależność współczynnika dyspersji mechanicznej od ciśnienia w zakresie ciśnień 1-6 bar.

EN

Expts. of N2 displacement with MeH in rock cores were carried out on the laboratory test stand. The math. model of the expt. was presented and the coeff. of mol. diffusion and mech. dispersion were detd. The dependence of the mech. dispersion coeff. on the pressure in the range of 1-6 bar was obsd.

15

Rule-based approximation of black-box classifiers for tabular data to generate global and local explanations

Maszczyk Cezary, Kozielski Michal, Sikora Marek

Annals of Computer Science and Information Systems

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2022

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Vol. 30

89--92

EN

The need to understand the decision bases of artificial intelligence methods is becoming widespread. One method to obtain explanations of machine learning models and their decisions is the approximation of a complex model treated as a black box by an interpretable rule-based model. Such an approach allows detailed and understandable explanations to be generated from the elementary conditions contained in the rule premises. However, there is a lack of research on the evaluation of such an approximation and the influence of the parameters of the rule-based approximator. In this work, a rule-based approximation of complex classifier for tabular data is evaluated. Moreover, it was investigated how selected measures of rule quality affect the approximation. The obtained results show what quality of approximation can be expected and indicate which measure of rule quality is worth using in such application.

16

Intuitionistic fuzzy model of the Hungarian algorithm for the salesman problem and software analysis of a shipping company example

Traneva Velichka, Mavrov Deyan, Tranev Stoyan

Annals of Computer Science and Information Systems

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2022

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Vol. 30

383--386

EN

Here we propose for the first time a temporal intuitionistic fuzzy extension of the Hungarian method for solving the Travelling Salesman Problem (TIFHA-TSP) based on intuitionistic fuzzy logic and index matrices theories. The time for passing a given route between the settlements depends on different factors. The expert approach is used to determine the intuitionistic fuzzy time values for passing the routes between the settlements. The rating coefficients of the experts take the times into account. We are also developing an application for the algorithm's provision to use it on a real case of TIFHA-TSP.

17

The influence of the PCB design and the process of their manufacturing on the possibility of a defect-free production

Vasilyev Fedor, Isaev Vladimir, Korobkov Maksim

Przegląd Elektrotechniczny

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2021

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R. 97, nr 3

91--96

EN

The influence of the design parameters (width of the conductor, thickness of the copper foil and gap between the conductors) of the printed circuit board and the characteristics of the technological process of its production: stages of exposure and etching, on the output of defectfree products is considered. According to the results of the study, analytical dependences were obtained, which make it possible to determine the minimum width of the conductor depending on the thickness of the copper foil and etching factor. There is the model proposed that links the probability of manufacturing a defect-free printed circuit board with the parameters considered. The developed model can be extended with other design parameters and models of technological stages.

PL

W pracy dokonano oceny wpływu parametrów konstrukcyjnych płytki drukowanej (szerokości ścieżki, grubości folii miedzianej i szczeliny między ścieżkami) oraz charakterystyki procesu technologicznego jej wytwarzania: etapy naświetlania i trawienia, na wytwarzanie płytek PCB wolnych od wad. W ramach badań uzyskano zależności analityczne, które pozwalają określić minimalną szerokość ścieżki w zależności od grubości folii miedzianej oraz tzw. współczynnika trawienia. Zaproponowano model łączący prawdopodobieństwo wyprodukowania płytki drukowanej wolnej od defektów z rozważanymi w pracy parametrami. Opracowany model można rozszerzyć o inne parametry projektowe oraz modele etapów technologicznych podczas wytwarzania PCB.

18

Modelling of work of the rotor-type blade pump with revolving stator

Dmytriv V. T., Lanets O. S., Dmytriv I. V., Horodetskyy I. M.

International Journal of Applied Mechanics and Engineering

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2021

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Vol. 26, no. 4

17--28

EN

In the article, the analytical dependences of modelling the cell cross-sectional area between two adjacent blades of a rotary blade pump and capacity for a pump with fixed and rotating stators are given, and analytical dependences are derived to model the power necessary to overcome the friction forces of the blades. The forces acting on the radially placed blade of a rotary pump with a fixed stator (non-rotating or stationary) and a rotating stator are analyzed. Design and technological parameters that influence the pump capacity and power are taken into account. The power required for the movement of the pump blade without taking into account the compression of the air has the opposite character of the change as to the pump capacity The capacity of a rotary pump with a rotating stator is three times higher than that of a stationary stator. The rotary pump with a rotating stator, with six radially spaced blades, consumes 0.854 [kW] less power to overcome the blade friction of 1313 kW The results of modelling of the pump work are given.

19

Influence of the movement of involute profile gears along the off-line of action on the gear tooth position along the line of action direction

Jedliński Łukasz

Eksploatacja i Niezawodność

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2021

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Vol. 23, no. 4

736--744

EN

When gears change their distance along the off-line of action (OLOA) direction, this affects the distance between the working surfaces of the meshing teeth along the line of action (LOA). This effect is usually neglected in studies. To include this effect precise equations are derived for spur gears. The analysis is carried out for the general case of spur gears with shifted profiles frequently used in the industry. The influence of OLOA gear displacement on LOA direction is also a function of gears parameters. An analysis is conducted, and the impact of parameters such as module, pressure angle, gear ratio, and the number of teeth is determined. As an example, a simulation of a 12 DOF analytical model is presented. The movement of gears along OLOA is caused by a frictional force that can be high during tooth degradation e.g. scuffing. Results show that when the movement of gears along the OLOA direction is significant, its influence on the distance between the mating teeth should not be neglected.

20

Analytical Models for Optimal Design of a Trapezoidal Composite Channel Cross-Section

Pourbakhshian Somayyeh, Pouraminian Majid

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 1

118--138

EN

In this paper, several analytical models are presented for the optimal design of a trapezoidal composite channel cross-section. The objective function is the cost function per unit length of the channel, which includes the excavation and lining costs. To define the system, design variables including channel depth, channel width, side slopes, freeboard, and roughness coefficients were used. The constraints include Manning’s equation, flow velocity, Froude number, and water surface width. The Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm was used to solve the optimization problem. The results are presented in three parts; in the first part, the optimal values of the design variables and the objective function are presented in different discharges. In the second part, the relationship between cost and design variables in different discharges is presented in the form of conceptual and analytical models and mathematical functions. Finally, in the third part, the changes in the design variables and cost function are presented as a graph based on the discharge variations. Results indicate that the cost increases with increasing water depth, left side slope, equivalent roughness coefficient, and freeboard.