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Evolution and Adaptability of Complex Applications
Polák, Marek ; Holubová, Irena (advisor) ; Rahayu, Wenny (referee) ; Krátký, Michal (referee)
Evolution and Adaptability of Complex Applications Abstract In these days the applications become more complex that causes maintenance problems while evolving these applications. A change in one part of the applica- tion can significantly affect other parts of the application. The next aspect can be related systems which communicate with this application. They must be up- dated to satisfy their correct functionality. These problems can concern multiple domains, e.g., UML diagrams, XML schema diagrams, relational schemas, APIs, etc. We focus on this problem from the perspective of the MDA, which uses the platform independent model (PIM) for a general view of the problem and the platform specific model (PSM) for particular domains. Moreover, these models can be interconnected and related to each other. We propose novel PSM models from various widely used domains, operations over these models and algorithms for model transformations. Thanks to the MDA principle, it is possible to combine presented models and model a complex application. All models and related algorithms we present were experimentally implemented and tested in the DaemonX framework on real-world data for their verification. 1
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Evolution and Adaptability of Complex Applications
Polák, Marek ; Holubová, Irena (advisor) ; Rahayu, Wenny (referee) ; Krátký, Michal (referee)
Evolution and Adaptability of Complex Applica- tions Abstract In these days the applications become more complex that causes maintenance problems while evolving these applications. A change in one part of the appli- cation can significantly affect other parts of the application. The next aspect can be related systems which communicate with this application. They must be updated to satisfy their functionality. These problems can concern multiple do- mains, e.g., UML diagrams, XML schema diagrams, relational schemas, etc. We focus on this problem from the perspective of the MDA, which uses the platform independent model (PIM) for a general view of the problem and the platform specific model (PSM) for particular domains. Moreover, these models can be in- terconnected. We propose novel PSM models from various widely used domains, operations over these models and algorithms for model transformations. Thanks to the MDA principle, it is possible to combine presented models and model a complex application. All models and related algorithms we present were experi- mentally implemented and tested in the DaemonX framework on real-word data for their verification. 1
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Recommender systems - models, methods, experiments
Peška, Ladislav ; Vojtáš, Peter (advisor) ; Jannach, Dietmar (referee) ; Krátký, Michal (referee)
This thesis investigates the area of preference learning and recommender systems. We concentrated recommending on small e-commerce vendors and efficient usage of implicit feedback. In contrast to the most published studies, we focused on investigating multiple diverse implicit indicators of user preference and substantial part of the thesis aims on defining implicit feedback, models of its combination and aggregation and also algorithms employing them in preference learning and recommending tasks. Furthermore, a part of the thesis focuses on other challenges of deploying recommender systems on small e-commerce vendors such as which recommending algorithms should be used or how to employ third party data in order to improve recommendations. The proposed models, methods and algorithms were evaluated in both off-line and on-line experiments on real world datasets and on real e-commerce vendors respectively. Datasets are included to the thesis for the sake of validation and further research. Powered by TCPDF (www.tcpdf.org)
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Analysis of Real-World Data and Their Exploitation
Stárka, Jakub ; Holubová, Irena (advisor) ; Krátký, Michal (referee) ; Collard, Martine (referee)
Title: Analyses of Real-World Data and Their Exploitation Author: Mgr. Jakub Stárka Department: Department of Software Engineering Supervisor: RNDr. Irena Holubová, Ph.D. Abstract: The typical optimization strategy of many data processing techniques is ex- ploitation of the knowledge of constructs typically used in real-world applications. However, such approach requires a repeatable, updatable and detailed analysis of a rep- resentative data set. Having such a requirement a number of related problems arises, such as automatic crawling of the data, data extraction, schema inference, and efficient performance of analyses over a huge data volume as well as exploitation of the results in current applications. In this thesis we describe a complex framework for performing statistical analyses of real-world documents and we propose characteristics that appropriately capture and describe features of XML documents, RDF triples and XQuery queries. Additionally we provide experimental results over a few selected real-world data sets. Last but not least we introduce an easily extensible tool that enables one to implement, test and compare new modules of the XML schema inference process. We describe not only the framework, but the area of schema inference in general, including related work and open problems. Keywords:...
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Conceptual Modeling for XML
Nečaský, Martin ; Pokorný, Jaroslav (advisor) ; Krátký, Michal (referee) ; Thalheim, Bernhardt (referee)
XML is a popular format for data representation. As the amount of data represented in XML grows, it is necessary to concentrate on the process of modeling XML schemes of the XML representations. However, modeling the XML schemes on the level f XML schema languages, such as XML Schema, has some drawbacks. A natural idea to improve this situation is to model the XML schemes rst on the conceptual level. It is motivated by the world of relational databases where we also start modeling the data fi rst on the conceptual level. In this thesis we focus on conceptual modeling for XML. We start with a motivating example to point out to several problems that can arise when using only XML schema languages for modeling XML schemes. We discuss how modeling the data rst on the conceptual level can help. We also show that conceptual modeling for XML has some speci cs that should be taken into account by a conceptual model for XML. Mainly, we show that it is necessary to separate the conceptual modeling process to two parts. First, we need to model the data independently of its representation in XML. Second, we need to model how the data is represented in di erent types of XML documents. In the next step, we analyze in detail existing approaches to conceptual modeling for XML and show their limitations. In the main part of...
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XML Data in (Object-) Relational Databases
Mlýnková, Irena ; Pokorný, Jaroslav (advisor) ; Krátký, Michal (referee) ; Osswald, R. (referee)
As XML has become a standard for data representation, it is inevitable to propose and implement techniques for e±cient managing of XML documents. A natural alternative is to exploit features and functions of (object-)relational database management systems, i.e. to rely on their long theoretical and practical history. The main concern of such techniques is the choice of an appropriate XML-to-relational mapping strategy. In this thesis we focus on further enhancing of current most e±cient XML-to-relational storage strategies { so-called adaptive methods. Firstly, we perform a detailed analysis of existing works and especially remaining open issues. Secondly, we propose their enhancing which can be characterized as a hybrid user-driven adaptive mapping strategy, i.e. a combination of so-called user-driven and adaptive methods. In the enhancing we focus especially on deeper exploitation of user-given information, i.e. schema annotations, and we propose an approach which enables to identify new annotation candidates and thus to help users to nd a more appropriate mapping strategy. For this purpose we propose a similarity measure which focuses mainly on structural similarity of the given data and an algorithm which enables reasonable tuning of its parameters on the basis of results of statistical analysis of...
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Bulk Evaluation of User-Defined Functions in XQuery
Bednárek, David ; Král, Jaroslav (advisor) ; Kuznetsov, Sergey (referee) ; Krátký, Michal (referee)
XPath queries are usually translated into an algebra that combines traditional relational operators and XML-speciffic ones. In particular, FLWOR loops are represented using nest, unnest, join, and similar operators and their original nested-loop nature disappears, creating an opportunity for bulk evaluation and join reordering. In XQuery, two additional issues shall be handled - tree construction and the presence of user-deffined functions. The recursive nature of functions pushes the problem outside of the range of relational algebra. This thesis presents a novel evaluation framework based on an expanding network of relational operators, called R-program. In this environment, functions are evaluated in bulk instead of evaluating each call separately. Besides obvious advantages of bulk evaluation, R-programs also allow rearrangement of data flow across function boundaries. A set of program transformations employing these capabilities is described; together with rule-based static interprocedural analysis algorithms used to determine the applicability of the transformations.
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Electrical machines fault simulator
Krátký, Michal ; Krbal, Michal (referee) ; Šlezingr, Jan (advisor)
The goal of this bachelor’s thesis is the laboratory task focused on vibrodiagnostics of rotating electrical machines. The thesis is divided into theoretical and practical part. The theoretical part is made of information related to rotating electrical machine mainly its faults and technical diagnostics. Besides that the vibrodiagnostics is involved into the theoretical part as well. The practical part deals with the design of laboratory task focused on vibrodiagnostics of rotating electrical machines. There is shown how vibrations influence the machine during the operation. There is used asynchronous machine 1LA7080 and vibrometer MV-5L and noncontact tachometer UNI-T UT372 for this experiment. The second task is the starting current diagnostics. The starting current ofthe engine with the rotor asymmetry 1LA7080 and rotor symmetry 1LA7090 is going to be analyzed here. On these engines will be shown, how current flicks affectthe magnetic field of the engine in the air gap.
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