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Feature extraction from image data
Uher, Václav ; Beneš, Radek (referee) ; Burget, Radim (advisor)
Image processing is one area of signal analysis. This thesis is involved in feature extraction from image data and its implementation using Java programming language. The main contribution of this thesis lies in develop features extractors and their implementation in the program RapidMiner. The result is a robust tool for image analysis. The functionality of each operator is tested on mammogram images. A function model was developed for the removal of artifacts from the mammography images. The success rate of removal is comparable with other similar works. Furthermore, learning algorithms were compared on example detection of ventricle in ultrasound image.
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Procedural programming in database
Nimrichter, Adam ; Povoda, Lukáš (referee) ; Uher, Václav (advisor)
Thesis deals with verification of concept of performing calculations inside database. Describes PostgreSQL database, its features and procedural language PL/pgSQL. Also focuses on machine learning methods, implementation of forward selection algorithm and verification of his functionality. Frequently used tool is MADlib, which is an open-source library of scalable in-database algorithms for machine learning, statistics and other analytic tasks.
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Time series analysis using deep learning
Hladík, Jakub ; Kolařík, Martin (referee) ; Uher, Václav (advisor)
The aim of the thesis was to create a tool for time-series prediction based on deep learning. The first part of the work is a brief description of deep learning and its comparison to classical machine learning. In the next section contains brief analysis of some tools, that are already used for time-series forecasting. The last part is focused on the analysis of the problem as well as on the actual creation of the program.
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Email spam filtering using artificial intelligence
Safonov, Yehor ; Uher, Václav (referee) ; Kolařík, Martin (advisor)
In the modern world, email communication defines itself as the most used technology for exchanging messages between users. It is based on three pillars which contribute to the popularity and stimulate its rapid growth. These pillars are represented by free availability, efficiency and intuitiveness during exchange of information. All of them constitute a significant advantage in the provision of communication services. On the other hand, the growing popularity of email technologies poses considerable security risks and transforms them into an universal tool for spreading unsolicited content. Potential attacks may be aimed at either a specific endpoints or whole computer infrastructures. Despite achieving high accuracy during spam filtering, traditional techniques do not often catch up to rapid growth and evolution of spam techniques. These approaches are affected by overfitting issues, converging into a poor local minimum, inefficiency in highdimensional data processing and have long-term maintainability issues. One of the main goals of this master's thesis is to develop and train deep neural networks using the latest machine learning techniques for successfully solving text-based spam classification problem belonging to the Natural Language Processing (NLP) domain. From a theoretical point of view, the master's thesis is focused on the e-mail communication area with an emphasis on spam filtering. Next parts of the thesis bring attention to the domain of machine learning and artificial neural networks, discuss principles of their operations and basic properties. The theoretical part also covers possible ways of applying described techniques to the area of text analysis and solving NLP. One of the key aspects of the study lies in a detailed comparison of current machine learning methods, their specifics and accuracy when applied to spam filtering. At the beginning of the practical part, focus will be placed on the e-mail dataset processing. This phase was divided into five stages with the motivation of maintaining key features of the raw data and increasing the final quality of the dataset. The created dataset was used for training, testing and validation of types of the chosen deep neural networks. Selected models ULMFiT, BERT and XLNet have been successfully implemented. The master's thesis includes a description of the final data adaptation, neural networks learning process, their testing and validation. In the end of the work, the implemented models are compared using a confusion matrix and possible improvements and concise conclusion are also outlined.
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Communication infrastructure virtualization platform
Stodůlka, Tomáš ; Martinásek, Zdeněk (referee) ; Uher, Václav (advisor)
The thesis deals with selection of infrastructure virtualization platform focusing on containerization with sandboxing support and with following examination of its difculty. The work begins with an explanation of the basic technologies such as: virtualization, cloud computing and containerization, along with their representatives, that mediate the technology. A special scope is defned for cloud computing platforms: Kubernetes, OpenStack and OpenShift. Futhermore, the most suitable platform is selected and deployed using own technique so that it fullflls all the conditions specifed by thesis supervisor. Within the difculty testing of the selected platform, there are created scripts (mainly in the Bash language) for scanning system load, creating scenarios, stress testing and automation.
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Computer analysis of medical image data
Krajčír, Róbert ; Šmirg, Ondřej (referee) ; Uher, Václav (advisor)
This work deals with medical image analysis, using variety of statisic and numeric methods implemented in Eclipse and Rapidminer environments in Java programming language. Sets of images (slices), which are used here, are the results of magnetic resonance brain examination of several subejcts. Segments in this 3D image are analyzed and some local features are computed, based on which data sets for use in training algorythms are generated. The ability of successful identification of healthy or unhealthy tissues is then practically tested using available data.
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Tool for deep neural network design
Hladík, Jakub ; Harár, Pavol (referee) ; Uher, Václav (advisor)
The aim of this thesis was to create a program for visualization of artificial neural networks. The first part contains definition of artificial neural networks, comparison with biological neural networks and comparison with processors used in personal computers. Also contains brief description of their function and advantages/disadvantages of artificial neural networks. The second part contains brief explanation of deep learning. There are described methods and models used for learning. The third part contains introduction to Caffe framework and summary of the most frequently occuring layers in neural networks, that are created by using Caffe. Next part contains brief analysis of created program as well as detailed description of classes, that program contains.
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Detection of anomalies in data center network traffic
Korzhasbayeva, Leila ; Uher, Václav (referee) ; Burget, Radim (advisor)
Ve velkých společnostech existuje spousta kriticky důležitých strojů pracujících bez přestávky každý den. Jednoduché Log Management řešení není vždy dostatečné k zachycení všech dat, která tečou produkčním prostředí. Ani bezpečnostní analytik není vždy schopen sledovat každý zdroj v prostředí, chytat změny v běžném provozu. Zde je bod, kde nám stroj může pomoci. Detekce anomálií v prostředí je hlavním cílem tohoto projektu. Existuje několik řešení prezentovaných a testovaných na datech ze serverů v reálném prostředí definované společnosti. Některé false positives stále se mohou objevovat, ale je to dobrá příležitost k vyřešení v budoucím výzkumu.
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Speech recognition using Sphinx-4
Kryške, Lukáš ; Uher, Václav (referee) ; Burget, Radim (advisor)
This diploma thesis is aimed to find an effective method for continuous speech recognition. To be more accurate, it uses speech-to-text recognition for a keyword spotting discipline. This solution is able to be applicable for phone calls analysis or for a similar application. Most of the diploma thesis describes and implements speech recognition framework Sphinx-4 which uses Hidden Markov models (HMM) to define a language acoustic models. It is explained how these models can be trained for a new language or for a new language dialect. Finally there is in detail described how to implement the keyword spotting in the Java language.
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Image similarity based on colour
Hampl, Filip ; Přinosil, Jiří (referee) ; Uher, Václav (advisor)
This diploma thesis deals with image similarity based on colour. There are discussed necessary theoretical basis for better understanding of this topic. These basis are color models, that are implemented in work, principle of creating the histogram and its comparing. Next chapter deals with summary of recent progress in the field of image comparison and overview of several most used methods. Practical part introduces training image database, which gives results of success for each created method. These methods are separately described, including their principles and achieved results. In the very end of this work, user interface is described. This interface provides a transparent presentation of the results for the chosen method.
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