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Machine learning in audio effects
Sychra, Jakub ; Mošner, Ladislav (oponent) ; Černocký, Jan (vedoucí práce)
Reverse engineering audio effects from mixed tracks is a complex topic requiring signal processing and music engineering experience. This work aims at creation of a system capable of identifying the sequence and parameters of guitar effects from a mixed audio track. Training data was created using clean guitar sounds from IDMT-SMT-Audio-Effects, augmented by known effects (BitCrush, Chorus, Clipping, Compressor, Delay, Distortion, High-pass filter, Ladder filter, Low-pass filter, Limiter, Phaser and Reverb), all implemented with a Python wrapper around standard VST effects. The system is based on VGGish neural network architecture with several classification (presence of effects) and regression (parameters of effects) heads. The performance of the algorithm is evaluated on classification and regression accuracy, as well as in informal listening tests.
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Optimization of DDoS Attack Mitigation based on Machine Learning
Banák, Filip ; Šišmiš, Lukáš (oponent) ; Kučera, Jan (vedoucí práce)
DDoS attacks using the TCP protocol are still amongst the most common. This thesis aims to take advantage of information present in TCP SYN messages to improve DDoS attack detection success rate. TCP SYN fingerprints are proposed as an additional data source to consider when computing features for DDoS detection. A combination of an existing feature extraction and aggregation system with an existing autoencoder-based anomaly detector is significantly optimized and extended to make use of SYN fingerprints. The experimental results show decent DDoS detection improvements on relevant datasets. The detector is 16 and 95 times faster to train and execute respectively. The extraction and aggregation system is 23 times faster.
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Meta-heuristické algoritmy pro výběr příznaků v klasifikaci srdečních onemocnění
Švestková, Tereza ; Odstrčilík, Jan (oponent) ; Mézl, Martin (vedoucí práce)
Tato práce je věnována postupům při výběru relevantních příznaků pro klasifikační úlohy týkající se srdečních onemocnění. Optimální výběr příznaků je klíčovým faktorem pro správnou funkčnost klasifikačních modelů a v případě medicíny pro zlepšení diagnostiky. Teoretická část pojednává o obecné klasifikační úloze ve strojovém učení. Dále jsou podrobněji popsány některé klasické postupy i novější meta-heuristické algoritmy pro efektivní selekci příznaků. Praktická část se věnuje aplikaci některých popsaných algoritmů na datové soubory související se srdečním onemocněním. Na základě ověření validity výsledku klasifikačního modelu podle vybraných příznaků běžnými postupy i evolučními algoritmy jsou diskutovány výhody a přínosy upřednostnění meta-heuristických algoritmů.
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Detekce malware domén pomocí metod strojového učení
Ebert, Tomáš ; Poliakov, Daniel (oponent) ; Hranický, Radek (vedoucí práce)
Tato bakalářská práce se zabývá detekcí malware domén pomocí metod strojového učení na základě různých informací získaných o doméně (DNS záznamy, geolokační údaje atd.). S rychle rozšiřujícími se hrozbami, nejen formou malwaru, jsou často současné přístupy nedostačující ať už jen rychlostí detekce malware domén, nebo celkovým rozeznáním, zda se jedná o nebezpečnou doménu. Výstupem této práce je natrénovaný model klasifikátoru XGBoost, jehož výhodou je rychlá a efektivní detekce v reálném čase oproti detekci pomocí černých listin, které získávají data domén často s týdenním zpožděním. Pro tento model bylo získáno 131 tisíc malware domén, pomocí kterých bylo možné získat model s vysokými hodnotami. Pomocí experimentů bylo dosaženo skóre F1 96.8786 % u klasifikátoru XGBoost s poměrem falešně pozitivních detekcí 0.004887.
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Optimization of Classification Models for Malicious Domain Detection
Pouč, Petr ; Jeřábek, Kamil (oponent) ; Hranický, Radek (vedoucí práce)
This thesis focuses on the development of advanced methods for malicious domain name detection using optimization techniques in machine learning. The thesis investigates and evaluates the effectiveness of different optimization strategies for classification. As evaluation tools, I selected classification algorithms that differ in their approach, including deep learning, decision tree techniques, or hyperplane search. These methods are investigated in terms of their ability to effectively classify domain names depending on the implemented optimization techniques. Optimization strategies include the creation of ground-truth datasets, application of data processing methods, advanced feature selection, solving the class imbalance problem, and hyperparameter tuning. The final part of the paper presents a detailed analysis of the benefits of each optimization approach. The experimental part of the study demonstrates exceptional results by combining several methodologies. The top CNN models obtained up to 0.9926 F1 while lowering FPR to 0.3%. The contribution of this study is to provide specific methodologies and tactics for the successful identification of malicious domain names in the cybersecurity area.
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Implementing gesture recognition on ARM as an alternative to traditional device control
Gajdošík, Richard ; Zbořil, František (oponent) ; Kočí, Radek (vedoucí práce)
This bachelor's thesis focuses on the development and implementation of a gesture recognition system on ARM architecture, utilizing the i.MX 93 board and TensorFlow Lite. The project is grounded in the application of neural networks for the recognition of hand gestures, offering an alternative to traditional device control methods. An integral part of the work involves a comprehensive analysis of existing gesture recognition solutions, identifying their strengths and potential improvements. The thesis elaborates on the design, development, and optimization of a real-time gesture recognition model specifically for ARM chips, emphasizing efficiency and performance. Additionally, the thesis covers the creation of a demonstrative application that visually represents recognized gestures. User testing is conducted to evaluate the practicality and user experience of the gesture recognition system, providing valuable feedback for future enhancements.
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Analyzing a person’s handwriting for recognizing his/her emotional state
Chudárek, Aleš ; Matoušek, Jiří (oponent) ; Malik, Aamir Saeed (vedoucí práce)
Emotion recognition from handwriting is a challenging and interdisciplinary task that can provide insights into the psychological and emotional aspects of the writer. In this study, we developed and evaluated a machine learning model that can predict the emotional state of a writer from their handwriting samples. We utilized the EMOTHAW dataset, which consists of handwriting and drawing samples from subjects whose emotional states are measured by the DASS test, which gives a score for depression, anxiety, and stress and the CIU Handwritten database for verification and experimentation. We extracted a large number of features that are inspired by the standard graphology work, as well as features that are specific to online data. We used ANOVA to select statistically significant features and normalized the data using Z-Score, MinMax, IQR or Log. We reduced the dimensionality of the features using Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA). We employed a meta approach Ensemble learning that seeks to reduce the errors of a single model by exploiting the diversity and complementarity of multiple models. The structure of our classifier is dependent on multiple arguments resulting in over 300,000 different configurations. We optimized arguments using argument freezing. We found the best classifiers for binary and trinary classification for each emotion, resulting in six optimal models. We evaluated our models using different metrics, such as accuracy, precision, recall, and F1-score. Our models reached adequate results in all metrics. In addition to finding the classifiers, this thesis explored the importance of each extracted feature, providing a sorted list of the most significant features used for emotion recognition from handwriting. We also enhanced the EMOTHAW database by identifying tasks that are more indicative of specific emotions, thereby reducing the need for a full task battery for emotional analysis.
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Diagnosing anxiety and depression from brain electroencephalogram (EEG) signals
Osvald, Martin ; Jaroš, Marta (oponent) ; Malik, Aamir Saeed (vedoucí práce)
Mental disorders represent inevitable emotions in our society. These psychological states affect the cognitive, emotional and behavioural functioning of individuals. Common men- tal disorders fall into two main diagnostic categories: depressive disorders and anxiety disorders. The aim of this work is to find a new method for detecting whether a given patient suffers from anxiety or depression using EEG classification. In this work, we use a combination of genetic algorithms and models from deep learning.
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Detection of DGA-based Botnets
Keznikl, Matej ; Setinský, Jiří (oponent) ; Hranický, Radek (vedoucí práce)
Botnets represent significant cybersecurity threats due to their potential to cause extensive damage to computer networks and systems. One primary method by which botnets conceal their existence and communicate with servers is through the use of Domain Generation Algorithms (DGA), which enable the dynamic creation of domain names for controlling the botnet. This thesis focuses on the design and development of a highly efficient and distributed detection system for analyzing communication patterns and behaviors of botnets within DNS network traffic and identifying domain names created based on DGA. Several machine learning techniques were compared, utilizing lexical features of domain names characteristic of DGA, to determine the classifier exhibiting the best results. The LightGBM classifier, achieving a ROC-AUC score of up to 99.18%, was subsequently integrated into the detection system. Unit testing of individual blocks and integration testing were performed to ensure the functionality and reliability of the entire system and the mutual compatibility of its components. The resulting implementation of the detection system achieves high accuracy in the binary classification of domain names created based on DGA, ensuring its readiness for effective deployment in real-world operational environments.
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