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Viscoelastic deformation of planetary bodies
Pilař, Štěpán ; Čadek, Ondřej (advisor) ; Čížková, Hana (referee)
Loading a planet's surface causes it to deform. The evolution of this deformation is influenced by the internal structure of the planet. In this thesis we use a one-dimensional numerical model of Maxwell viscoelastic deformation of a spherical shell to test the effect of a few selected parameters of lithosphere and mantle on the specific case of loading of the Martian surface by the North Polar cap. The ice sheet is less than 10 million years old and the measured surface deformation under it is about 100 m. We chose elastic lithosphere thickness and viscous profile of the lithosphere and mantle as the model parameters to be tested, the other parameters according to the results of InSight mission. We made the viscosity profile either piecewise constant or defined by an Arrhenius formula. The magnitude of deformation is mostly influenced by the elastic lithosphere thickness. To realize the deformation observed on Mars, our models with piecewise constant viscosity require the lithospheric thickness to be Te = 200 − 300 km, Arrhenius formula based models require Te ≥ 300 km.
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Latent heat effect on slab deformation in the Earth mantle
Pilař, Štěpán ; Čížková, Hana (advisor) ; Běhounková, Marie (referee)
Lithospheric plates move relative to each other with velocities of several cm/year. In subduction zone, one plate slides (subducts) under the other. Slabs are being deformed while subducting to the Earth's mantle. The subduction is influenced by phase tran- sitions of the mantle material at the depths of 410 km and 660 km. Here, we used a two-dimensional numerical model of subduction to evaluate the influence of latent heat released or absorbed during these phase transitions on the subduction process. We ex- amined the influence of latent heat alongside the influence of other parameters - age of the slab (50 - 150 million years), yield stress inside the slab (2 · 108 − 5 · 108 Pa) and viscosity of the crust (1020 −1021 Pa s). Latent heat released during an exothermic phase transition at the depth of 410 km heats up the slab by 50 - 90 K, reduces the density anomaly with respect to the surrounding mantle and slows down the slab. At the same time, the viscosity of the slab is lowered and the slab deforms more easily in the transi- tion zone due to the endothermic phase transition at the depth of 660 km and a viscosity resistance of a stiffer lower mantle. The stress inside a slab is therefore lowered, which may influence deep earthquakes. When it comes to the other parameters, age of the slab changes the...
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Componentization of Linked Data Transformations
Pilař, Štěpán ; Mynarz, Jindřich (advisor) ; Knap, Tomáš (referee)
The diploma thesis is focused on transformation of linked data and opportunities for componentization of extract, transform, load process resulting in reusability of such components. UnifiedViews serves as a framework for demonstration of implementa-tion of selected components. Initial review of related fields of study, relational data oriented ETL and linked data quality management being most prominent, is followed by bottom-up analysis of existing extractors and transformations. Identified common transformations are supplemented by operations known from transformations of relational data. Options and limits of each component candidate are discussed as well as possible cooperation with other components. The next section discusses supported ways of implementation in the selected environment and provides a list of key questions for decision making process is provided. The last part describes implementation of selected components with respect to the approach suggested in the preceding section. Practical use as well as limitations of the implemented components are demonstrated on tasks transforming public contracts datasets.
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Platform-as-a-Service for running PHP applications
Pilař, Štěpán ; Mittner, Jan (advisor) ; Burkoň, Lukáš (referee)
There are numerous web applications written in PHP language, most of whose requirements exceed common shared hosting offerings. This work deals with using Platform-as-a-Service solutions for running PHP applications. The advantages and disadvantages of PHP Platform-as-a-Service solutions are discussed in the first part of this work along with their effect on applications' architecture. The middle part compares available platforms with regard to their properties, functions and price models. The last part illustrates steps that have to be taken in order to accommodate applications' code for running in a cloud environment, moreover it demonstrates some of the advantages of cloud based web applications. The contribution of this work is in summarizing different aspects of cloud based PHP applications and a demonstration of running such an application.
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