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U-Net Convolutional Neural Network For Tem
Image Segmentation
Mocko, Štefan
This work deals with the use of a convolutional neural network in the area of segmentation of images acquired with the use of a transmission electron microscope. Paper describes programming tool for image data augmentation, used neural network topology, and it also provides information about model training. This neural network topology delivered excellent results on provided data from the Thermo Fisher Scientific company, which will serve as a starting point for internal company research in image segmentation area.
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Automatic 3D segmentation of brain images
Bafrnec, Matúš ; Dorazil, Jan (referee) ; Kolařík, Martin (advisor)
This bachelor thesis describes the design and implementation of the system for automatic 3D segmentation of a brain based on convolutional neural networks. The first part is dedicated to a brief history of neural networks and a theoretical description of the functionality of convolutional neural networks. It represents a fast introduction to the problematics and provides theoretical basics needed for the understanding and creation of the system. Individual layers of the neural network and principles of their functionality and mutual relations are also described in this part. The second part of the thesis is about problem analysis, designing of a solution and a comparison between neural networks and other solutions. The result of a magnetic resonance imaging of the head is a series of black-and-white images representing a 3D scan. The task is to tag a brain and to remove unnecessary information in the form of surrounding tissues. The final image of the brain can be utilized in a volumetry or during a diagnostic of neurodegenerative diseases. The advantage of neural networks in comparison with deterministic systems is their flexibility. They allow an adaptation to other segmentation problems just by changing the training dataset, without a need of changes in the architecture. One of the systems performing fully automatic 3D segmentation is called U-Net – its name comes from the similarity of the architecture with the letter U. Three real solutions, the first implementation of U-Net, extended U-Net and recurrent U-Net were presented. The first version of U-Net has been very memory-demanding, it required a training on a processor instead of a graphic card and has not allowed data processing in full resolution. The extended U-Net has resolved these problems by loading data in overlaying series of three images. In addition to the possibility of a training on a graphic card with related decrease in learning time, the accuracy was increased by adding interconnections to the internal architecture of the network. The last version, recurrent U-Net, aims for the optimization of extended U-Net based on the reusage of existing levels. This brings a decrease in a time and resource difficulty. The number of parameters of the network was lowered to less than 20%, without any increase in case of further level addition. This network is one of first recurrent networks used on the problem of 3D segmentation and provides a foundation to further research. The last part focuses on the evaluation of results and the comparison of accuracy, speed and requirements between particular networks. The accuracy of human and machine segmentation is also compared. The extended and recurrent U-Net have surpassed their human opponent, which in real case could save a lot of doctors time and prevent human mistakes. The result of this work is a theoretical basis providing an introduction to the problematics of convolutional neural networks and segmentation, fully working systems for automatic 3D segmentation and the foundation for further research in the field of recurrent networks.
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Word2vec Models with Added Context Information
Šůstek, Martin ; Rozman, Jaroslav (referee) ; Zbořil, František (advisor)
This thesis is concerned with the explanation of the word2vec models. Even though word2vec was introduced recently (2013), many researchers have already tried to extend, understand or at least use the model because it provides surprisingly rich semantic information. This information is encoded in N-dim vector representation and can be recall by performing some operations over the algebra. As an addition, I suggest a model modifications in order to obtain different word representation. To achieve that, I use public picture datasets. This thesis also includes parts dedicated to word2vec extension based on convolution neural network.
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Mushroom Detection and Recognition in Natural Environment
Steinhauser, Dominik ; Juránek, Roman (referee) ; Špaňhel, Jakub (advisor)
In this thesis is handled the problem of mushroom detection and recognition in natural environment. Convolutional neural networks are used. The beginning of this thesis is dedicated to the theory of neural networks. Further is solved the problem of object detection and classification. Using neural network trained for classification is solved also the task of localization. Results of trained CNNs are analised.
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Neural networks for automatic speaker, language, and sex identification
Do, Ngoc ; Jurčíček, Filip (advisor) ; Peterek, Nino (referee)
Title: Neural networks for automatic speaker, language, and sex identifica- tion Author: Bich-Ngoc Do Department: Institute of Formal and Applied Linguistics Supervisor: Ing. Mgr. Filip Jurek, Ph.D., Institute of Formal and Applied Linguistics and Dr. Marco Wiering, Faculty of Mathematics and Natural Sciences, University of Groningen Abstract: Speaker recognition is a challenging task and has applications in many areas, such as access control or forensic science. On the other hand, in recent years, deep learning paradigm and its branch, deep neural networks have emerged as powerful machine learning techniques and achieved state-of- the-art in many fields of natural language processing and speech technology. Therefore, the aim of this work is to explore the capability of a deep neural network model, recurrent neural networks, in speaker recognition. Our pro- posed systems are evaluated on TIMIT corpus using speaker identification task. In comparison with other systems in the same test conditions, our systems could not surpass reference ones due to the sparsity of validation data. In general, our experiments show that the best system configuration is a combination of MFCCs with their dynamic features and a recurrent neural network model. We also experiment recurrent neural networks and convo- lutional neural...
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Multitasking as a result of audiovisual media convergence
Mičke, David ; Moravec, Václav (advisor) ; Kasík, Pavel (referee)
The primary objective of this work is to determine the extent of media multitasking, as an increasing phenomenon in receptioning media content in the last 20 years; on news channels broadcast. The research sample consists of Czech station CT24, BBC and international version of the American CNN. In the theoretical section, the media convergence is explained in the basic terms and concepts; Following to this section, the thesis includes also a part dedicated to particular consequences of convergence in audiovisual media, which is associated with the multitasking. Moreover, the thesis also reflects multitasking's origin, reasons of its development and its impacts on human cognitive perception. On account of multitasking as a developing form of media reception, news channels react. In image analysis of technical codes associated with multitasking, which was undertaken at all channels for one week, are highlighted multitasking specifics of those channels. Included is a comparison of the differences between those news channels.
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Media image of the crimean crisis on Russia Today, CNN and ČT24 news
Štěpán, Petr ; Lokšík, Martin (advisor) ; Nečas, Vlastimil (referee)
This thesis analyses how three television stations - Czech ČT24, Russian RT and American CNN - informed about the Crimean crisis which took place in Ukraine in 2014. The first part of the thesis presents theoretical approach and mentions previous similar studies, which focused on examining of medial coverage and framing of war conflicts. Next chapter describes the history of Ukraine briefly and underlines events which could have caused the Crimean crisis. Thereafter the thesis introduces the timeline of the Crimean crisis. In the next part the thesis analyses sources, topics and keywords which appeared in the news of ČT24, RT and CNN. It also describes how particular people and events were visually covered. In the final chapter the approach of the three examined television channels is compared.
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Image segmentation using deeplearning methods
Lukačovič, Martin ; Burget, Radim (referee) ; Mašek, Jan (advisor)
This thesis deals with the current methods of semantic segmentation using deep learning. Other approaches of neaural networks in the area of deep learning are also discussed. It contains historical solutions of neural networks, their development, and basic principle. Convolutional neural networks are nowadays the most preferable networks in solving tasks as detection, classification, and image segmentation. The functionality was verified on a freely available environment based on conditional random fields as recurrent neural networks and compered with the deep convolutional neural networks using conditional random fields as postprocess. The latter mentioned method has become the basis for training of new models on two different datasets. There are various enviroments used to implement neural networks using deep learning, which offer diverse perform possibilities. For demonstration purposes a Python application leveraging the BVLC\,/\,Caffe framework was created. The best achieved accuracy of a trained model for clothing segmentation is 50,74\,\% and 68,52\,\% for segmentation of VOC objects. The application aims to allow interaction with image segmentation based on trained models.
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