Rafał Kieszek

Dr. Rafał Kieszek

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 June 2022 in Materials
Verified
Journal Article
Open access
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AKAdam Kozakiewicz
Adam Kozakiewicz
RKRafał Kieszek
Rafał Kieszek
The article presents the process of selecting and optimising artificial neural networks based on the example of determining the stress distribution in a disk-drum structure compressor stage of an aircraft turbine engine. The presented algorithm allows the determination of von Mises stress values which can be part of the penalty function for further mass optimization of the structure. A method of a parametric model description of a compressor stage is presented in order to prepare a reduced stress distribution for training artificial neural networks. A comparative analysis of selected neural network training algorithms combined with the optimisation of their structure is presented. A genetic algorithm was used to determine the optimal number of hidden layers and neurons in a layer. The objective function was to minimise the absolute value of the relative error and standard deviation of stresses determined by FEM and artificial neural networks. The results are presented in the form of the Pareto front due to the stochastic optimisation process.

30 April 2023 in Applied Sciences
Verified
Journal Article
Open access
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RKRafał Kieszek
Rafał Kieszek
Stanisław KachelStanisław Kachel
Stanisław Kachel
AKAdam Kozakiewicz
Adam Kozakiewicz
This article presents a genetic algorithm modification inspired by events related to great extinctions. The main objective of the modification was to minimize the number of objective function solutions until the minimum for the function was established. It was assumed that, within each step, a population should be smaller than that recommended in the applicable literature, the number of iterations should be limited, the solution area should be variable, and a great extinction event should take place following several iterations. Calculations were performed for 10 individuals within a population, 10 iterations, two generations each, with a great extinction event happening once every three iterations. The developed algorithm was presented, capable of indicating the minimum number of Eggholder and Rastrigin functions, with a higher probability than the master algorithm (default “ga” in MATLAB) at the same number of objective function solutions. An algorithm was proposed focusing on minimizing the randomization of the objective function, which may be an alternative to the surrogate model. Typically, the emphasis is on achieving as much accuracy as possible. This article presents a method for minimizing the randomization of the objective function and obtaining the highest possible accuracy. A method is presented which minimizes the disadvantages of the largest computation time and the need to generate many samples for typical genetic algorithms (GAs). Optimization results for the classic GA, GEGA, WOA, SMA, and SSA algorithms for the Eggholder and Rastrigin functions were compared. A modification of the genetic algorithm was made to obtain a global extreme with satisfactory accuracy and a sufficiently high probability, while minimizing the number of samples calculated on the basis of the objective function. The developed methodology was used to fulfill the target function for the turbine disc.

1 June 2021 in Advances in Science and Technology Research Journal
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Journal Article
Open access
RKRafał Kieszek
Rafał Kieszek
AKAdam Kozakiewicz
Adam Kozakiewicz
RRRobert Rogólski
Robert Rogólski
The paper presents the results of a series of numerical research on the possibility of applying Artificial Neural Networks (ANNs) for ultimate strength calculations of selected parts of rotating machines. The layout and the principle of the algorithm operation were described, beginning from the...

31 July 2024 in Journal of Theoretical and Applied Mechanics
Verified
Journal Article
Open access
RKRafał Kieszek
Rafał Kieszek
MMMaciej Majcher
Maciej Majcher
BSBorys Syta
Borys Syta
AKAdam Kozakiewicz
Adam Kozakiewicz

7 August 2023 in Advances in Science and Technology Research Journal
Verified
Journal Article
Open access
AKAdam Kozakiewicz
Adam Kozakiewicz
AKAleksandra Kołodziejska
Aleksandra Kołodziejska
RKRafał Kieszek
Rafał Kieszek
This article deals with the exhaust emissions from aircraft turbine engines, which is related to the rapidly growing market for this type of aircraft and its contribution to toxic emissions. The test carried out was done on a business jet turbine engine exhaust pollutants. The test object was the...