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The Impact of Image Resolution on the Precision of Content-based Retrieval
Navrátil, Lukáš ; Lokoč, Jakub (advisor) ; Skopal, Tomáš (referee)
This thesis is focused on comparing methods for similarity image retrieval. Common techniques and testing sets are introduced. The testing sets are there to measure the accuracy of the searching systems based on similarity image retrieval. Measurements are done on those models which are implemented on the basis of presented techniques. These measurements examine their results depending on the input data, used components and parameters settings, especially the impact of image resolution on the retrieval precision is examined. These results are analysed and the models are compared. Powered by TCPDF (www.tcpdf.org)
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Satellite data management and analysis
Krška, David ; Lokoč, Jakub (advisor) ; Nečaský, Martin (referee)
The aim of this bachelor thesis is to implement and test an interactive application for the analysis, visualization and classification of satellite data. The satellite data are preprocessed and automatically composed into colored images. The application allows to create and compare two types of classification algorithms. The first type uses single images and the second type uses multiple images of the same place, but at different times. We also created an interface for selecting and managing the training data. A few well-known classification algorithms of both types were implemented and their success rates were compared in an experiment. All the satellite data used in the experiment are from the Landsat program. The result of this bachelor thesis is an application primarily focused on classification. But the application could also be extended into a complex GIS system. Powered by TCPDF (www.tcpdf.org)
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Employing Parallel Architectures in Similarity Search
Kruliš, Martin ; Yaghob, Jakub (advisor) ; Platoš, Jan (referee) ; Pllana, Sabri (referee)
This work examines the possibilities of employing highly parallel architectures in database systems, which are based on the similarity search paradigm. The main objective of our research is utilizing the computational power of current GPU devices for similarity search in the databases of images. Despite leaping progress made in the past few years, the similarity search problems remain very expensive from a compu- tational point of view, which limits the scope of their applicability. GPU devices have a tremendous computational power at their disposal; however, the usability of this power for particular problems is often complicated due to the specific properties of this architecture. Therefore, the existing algorithms and data structures require extensive modifications if they are to be adapted for the GPUs. We have addressed all the aspects of this domain, such as efficient utilization of the GPU hardware for generic computations, parallelization of similarity search process, and acceleration of image indexing techniques. In most cases, employing the GPU devices brought a speedup of two orders of magnitude with respect to single-core CPUs and approximately one order of magnitude with respect to multiprocessor NUMA servers. This thesis summarizes our experience and discoveries from several years of research,...
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Ontological Reasoning with Taxonomies in RDF Database
Hoferek, Ondřej ; Nečaský, Martin (advisor) ; Svoboda, Martin (referee)
13548805670613-46162052c208770f99e83a586780d16c.txt As the technologies for the realisation of the idea of the Semantic Web have evolved rapidly during past few years, it is possible to use them in variety of applications. As they are designed with the ability to process and analyze semantic information found in the data in mind, they are particularly suitable for the task of enhancing relevance of the document retrieval. In this work, we discuss the possibilities of identifying a suitable subset of the expressing capabilities of the SPARQL querying language and create a component that encapsulates the technical details of its usage. Page 1
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Similarity Search in Protein Structure Databases
Galgonek, Jakub
Proteins are one of the most important biopolymers having a wide range of functions in living organisms. Their huge functional diversity is achieved by their ability to fold into various 3D structures. Moreover, it has been shown that proteins sharing similar structure often share also other properties (e.g, a biological function, an evolutionary origin, etc.). Therefore, protein structures and methods to identify their similarities are so widely studied. In this thesis, we introduce a system allowing similarity search in pro- tein structure databases. The system retrieves, given a query structure, all database structures being similar to the query structure. It employs several key components. We have introduced a novel similarity measure assigning similarity scores to pairs of protein structures. We have designed specific access method based on LAESA metric indexing and using the proposed measure. The access method allows to search similar structures more effi- ciently than when a sequential scan of a database is employed. To achieve further speedup, the measure and the access method have been parallelized, resulting in almost linear speedup with the respect to the number of available cores. The last component is a web user interface that allows to accept a query structure and to present a list of...
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Hlasové ovládání pro efektivní editaci textu
Citorík, Juraj ; Lokoč, Jakub (advisor) ; Skopal, Tomáš (referee)
The aim of this thesis is to provide a comprehensive introduction to digital sound processing and speech recognition. Selected speech recognition features as well as algorithms are introduced and utilized in a voice controlled text editor and a .NET class library. The performance of the features is evaluated in both speaker-dependent and speaker-independent recognition of commands related to text editing. The library provides a straightforward way of implementing a speaker-dependent, domain-constrained voice recognition in an arbitrary application. It is used in a simple voice controlled text editor. The editor allows the user to assign voice commands to built-in actions. In this way, it is possible for inexperienced users to access and use advanced features of the program without having to learn complex workflows. Moreover, this approach is language-agnostic and can even be used by people with speech impairments as opposed to majority of presently used voice recognition systems. The results of the experiments indicate that, given a recording of sufficient quality, the presented features and algorithms provide an effective means to implement a speaker-dependent speech recognition system, which can be used in a voice controlled text editor. Powered by TCPDF (www.tcpdf.org)
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Similarity search in Mass Spectra Databases
Novák, Jiří ; Skopal, Tomáš (advisor) ; Svozil, Daniel (referee) ; Nahnsen, Sven (referee)
Shotgun proteomics is a widely known technique for identification of protein and peptide sequences from an "in vitro" sample. A tandem mass spectrometer generates tens of thousands of mass spectra which must be annotated with peptide sequences. For this purpose, the similarity search in a database of theoretical spectra generated from a database of known protein sequences can be utilized. Since the sizes of databases grow rapidly in recent years, there is a demand for utilization of various database indexing techniques. We investigate the capabilities of (non)metric access methods as the database indexing techniques for fast and approximate similarity retrieval in mass spectra databases. We show that the method for peptide sequences identification is more than 100x faster than a sequential scan over the entire database while more than 90% of spectra are correctly annotated with peptide sequences. Since the method is currently suitable for small mixtures of proteins, we also utilize a precursor mass filter as the database indexing technique for complex mixtures of proteins. The precursor mass filter followed by ranking of spectra by a modification of the parametrized Hausdorff distance outperforms state-of-the-art tools in the number of identified peptide sequences and the speed of search. The...
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Podobnostní vyhledávání obrázků na webu
Grošup, Tomáš ; Lokoč, Jakub (advisor) ; Hoksza, David (referee)
The subject of this bachelor thesis is to design and create a web portal, enabling efficient indexing and content-based searching of images obtained from various free image databases (e.g., results from a keyword-based search engine). The portal provides fast feature extraction technique and for the visual similarity, the signature quadratic form distance is utilized. The search supports various user settings and comparison of their results. Search results can also be presented using a layout based on particle physics, which supports exploration and multi-query.
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Nové dynamické metody konstrukce pro PM-strom
Čech, Přemysl ; Lokoč, Jakub (advisor) ; Pangrác, Ondřej (referee)
With the emerging applications dealing with complex multimedia retrieval, such as the multimedia exploration, appropriate indexing structures need to be designed. A formalism for compact metric region description can significantly simplify the design of algorithms for such indexes, thus more complex and efficient metric indexes can be developed. In this thesis, we introduce the cut-regions comprising compact metric region description and basic operations. To demonstrate their power, we redefine the PM-Tree using the cut-regions and, moreover, use the formalism to improve the PM-Tree construction techniques. We have experimentally evaluated that the improved construction techniques lead to query performance originally obtained just using expensive construction techniques. Also in comparison with other metric and spatial access methods, the revisited PM-Tree proved its benefits.
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Similarity Search in Protein Structure Databases
Galgonek, Jakub ; Skopal, Tomáš (advisor) ; Porto, Markus (referee) ; Svozil, Daniel (referee)
Proteins are one of the most important biopolymers having a wide range of functions in living organisms. Their huge functional diversity is achieved by their ability to fold into various 3D structures. Moreover, it has been shown that proteins sharing similar structure often share also other properties (e.g, a biological function, an evolutionary origin, etc.). Therefore, protein structures and methods to identify their similarities are so widely studied. In this thesis, we introduce a system allowing similarity search in pro- tein structure databases. The system retrieves, given a query structure, all database structures being similar to the query structure. It employs several key components. We have introduced a novel similarity measure assigning similarity scores to pairs of protein structures. We have designed specific access method based on LAESA metric indexing and using the proposed measure. The access method allows to search similar structures more effi- ciently than when a sequential scan of a database is employed. To achieve further speedup, the measure and the access method have been parallelized, resulting in almost linear speedup with the respect to the number of available cores. The last component is a web user interface that allows to accept a query structure and to present a list of...
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