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Large Language Models for Generating Code Focusing on Embedded Systems
Vadovič, Matej ; Nosko, Svetozár (referee) ; Smrž, Pavel (advisor)
The goal of this work was to adapt a pre-trained language model for the purpose of generating code in the field of embedded systems. The work introduces a new dataset for fine-tuning code generation models, consisting of 50,000 pairs of source code and comments focused on embedded systems programming. This dataset is composed of collected source code from the GitHub platform. Two new language models for code generation, based on transformer architecture pre-trained models, were fine-tuned on the data of the new corpus. Model MicroCoder is based on the CodeLLaMA-Instruct 7B model, and during its fine-tuning, the QLoRA technique was used to minimize computational requirements. The second model, MicroCoderFIM, is based on the StarCoderBase 1B model and supports code infilling. The individual models were compared based on BLEU, CodeBLEU, ChrF++, and ROUGE-L metrics. Model MicroCoderFIM achieves the best adaptation results to the new task, with over 120% improvement in all measured metrics. The weights of the models along with the new dataset are freely accessible on a public repository.
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Analysis of Current Higher Harmonics Impact on Losses in Transformer Foil Winding
Žďárský, Jan ; Klíma, Petr (referee) ; Mrajca, Miroslav (advisor)
This paper deals with the analysis of the effects of non-sinusoidal current on the foil windings of power transformers. This issue is important in transformer design since losses are measured only when sinusoidal current is passed through. In some applications, these losses need to be recalculated to account for the effect of higher harmonics of the current in actual operation, as these losses are related to transformer heating. A literature search of available sources that have already described this issue is performed in this work. In this paper, a model for simulation in Ansys Maxwell environment is presented, using which the losses due to higher harmonics will be calculated.
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Analysis of Electrical Steel Additional Losses Caused by Stacking Holes
Kozlíček, Jiří ; Bílek, Vladimír (referee) ; Mrajca, Miroslav (advisor)
This bachelor's thesis deals with the analysis of losses in the electrical steel sheets of a distribution transformer, particularly the losses around stacking holes, which are used for stacking individual sheets during production. The thesis also includes standardized methods according to IEC 60404-2, 60404-3, and 60404-10, which can be used to determine the magnetic properties of materials used in transformers. Part of the thesis is the evaluation of the given issue using the finite element method, with the help of the Ansys program. Simulation models of 3 different types of sheets, which are commonly used in practice are designed in this program. The conclusion then focuses on quantifying the additional losses due to stacking holes, which is further discussed.
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Potential of neural networks using transformers for medical image processing
Valík, Tomáš ; Nohel, Michal (referee) ; Chmelík, Jiří (advisor)
This thesis explores the potential of neural networks based on transformer architecture for medical image processing. The main objective was to compare the performance of ResNet18 and Vision Transformer (ViT-B-16) models on two distinct datasets, specifically Intel Image Classification and ChestXray. The models were optimized using the Optuna framework and subsequently trained ten times each to ensure robustness of the results. These results indicate that models utilizing Vision Transformers achieve higher weighted F1 scores compared to ResNet18 models. Specifically, the ViT-B-16 model achieved the highest F1 score of 0.939 on the Intel Image dataset and 0.907 on the ChestXray dataset, whereas ResNet18 achieved scores of 0.883 and 0.885, respectively. Statistical analyses using the Wilcoxon test confirmed that the differences in performance between the models are statistically significant, suggesting an advantage of using Vision Transformers for these tasks. An analysis of computational complexity is also provided, highlighting that ViT requires significantly higher computational resources.
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Design of a transformer station for power output from a PV power plant and a diesel generator
Marák, Jiří ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This thesis is about design of a transformation station for power output from both a photovoltaic power plant and a diesel generator, serving as grid support. The primary objective is to devise a comprehensive solution including conceptualization, grid connection point, and transformer specifications capable of handling the 5 MW power output from the PV plant and the 1000 kW output from the diesel generator, including the calculation of short-circuit conditions. Furthermore, the thesis delves into the design of network breakpoints and protective measures.Lastly, it proposes dispatch control and billing metering in accordance with the operational requirements stipulated by the distribution system operator.
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Dynamic modelling of active railway traction feeders for power quality assessment
Bureš, Jan ; Doleček, Radovan (referee) ; Klusáček, Jan (advisor)
The thesis is focused on modelling of traction feeders for 25 kV 50 Hz traction system in order to assess the influence on voltage quality at point of the connection in 110 kV distribution grid. With respect to various technology of traction feeders, the feeder models, including conventional feeding system and modern converter stations, emphasize operating principle, detailed power circuit structure and description of influence on voltage quality in the distribution grid. The selected technologies of traction feeders are modeled in simulation software PSCAD and influence on voltage quality at the point of connection is assessed via an example, which reflects a realistic operation of traction vehicles in the typical traction system. The models are parametrizable and thus can be used for the connectivity assessment for the distribution system according to national distribution system operators’ standard PNE 33 3430-0. Moreover, the thesis also deals with the use of modern converter feeders for auxiliary frequency services. The operation principle is demonstrated on examples where the basic algorithm and requirements for control layer of converters is described. Finally, an algorithm for synchronization of the feeders supplying adjacent 25 kV 50 Hz railway traction system sections is designed and presented by means of simulation. In general, the thesis shows the use of dynamic models for connectivity assessment to the distribution grid in pre-project phase and for definition and development of converter feeders use cases upon feeding of the railway traction system.
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Identification of specified segments in the audio signal using machine learning
Pařízek, Radim ; Galáž, Zoltán (referee) ; Zvončák, Vojtěch (advisor)
The bachelor thesis deals with the design of a system for the identification of natural environmental sounds in audio recordings. The datasets and models used for this type of tasks are surveyed and their structure is described. A system for the identification of sounds in one layer and in two layers has been proposed for seven selected labels. The classifier used for this system was created by fine-tuning a transformer model from the Hugging Face platform. The results of two training approaches and one identification system were evaluated.
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An effect of natural phenomena on electrical devices
Müller, Michal ; Aubrecht, Vladimír (referee) ; Bušov, Bohuslav (advisor)
The Thesis deals with the impact of natural effects on electrical equipment. It describes the various natural effects and shows how it impacts, what it impacts on and what the source of its impact is. The main point of this Thesis is the issue of atmospheric charge (storm and lightning) and the issue of coronal mass ejection (CME). The Thesis shows causally consequences string of geomagnetical field disturbances and resultant power system impacts. There are mentioned historic storm events and power system impacts and description of events in Hydro-Quebec – the most important event. Of this species. At the end there are shows possible way of mitigation power system impacts.
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MV netwok design for 75 new houses in Damborice
Makuta, Peter ; Novák, Vojtěch (referee) ; Ptáček, Michal (advisor)
Content of this thesis is medium voltage network design for seventy five houses in Damborice. At the beginning author discuss about history of transmission network and distribution network. Next topic is about steady state of network. In theoretic part are different solving methods of linear and non-linear simultaneous equations discussed. Author describes four methods – method of node voltages, elimination of balance node, Gauss-Seidel and Newton method. The electric properties of both the overhead transmission lines and cable lines and their variety are part of this work too. There is purpose, forms and parameters of transformers described. Simplicity of author’s design should reduce the usage of many electrical elements visible to residents.
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Modular Power Supply for Formula Student
Ščípa, Samuel ; Bohrn, Marek (referee) ; Pavlík, Michal (advisor)
This bachelor thesis is focused on the theoretical analysis and design of switching power supply with galvanic isolation. The implementation of the design is in the form of the power and control part of the modular power supply. The device parameters are suited for the needs and requirements of the development department of the electric student formula. Design configuration achieves a maximum output voltage of 1000 V and a current of 100 mA, which are user-adjustable.
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