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Dynamical processes in Jupiter's and Saturn's ring systems
Řehák, Matyáš ; Brož, Miroslav (advisor) ; Hanuš, Josef (referee)
The main subject of this thesis is a review of dynamical processes acting in Jupiter's and Saturn's rings. The thesis is divided into three chapters. Observed orbital and physical characteristics of the rings are described in the first one. In Chapter 2, we discuss physical processes forming the rings. Tidal disruptions, mutual collisions of ring particles, meteoroid bombardment and ballistic transport are among them. Various electromagnetic effects are analyzed too - e.g. the Poynting-Robertson effect, the Lorentz resonaces, plasma drag and radiation pressure. Yet another types of phenomena are resonant gravitational influence of satellites, shepherding moons and also collective dynamics of ring particles which results in formation of spiral waves. Finally, there is a review of theories concerning the origin of Saturn's rings in Chapter 3. We can distinguish three types of models - a disruption of a moon, a disruption of an external body and a formation from protolunar matter. At present, a tidal disruption of large differentiated moon seems to be the most probable theory.
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Asteroid Models from Sparse Photometry
Hanuš, Josef
We investigate the photometric accuracy of the sparse data from astrometric surveys available on AstDyS. We use data from seven surveys with the best accu- racy in combination with relative lightcurves in the lightcurve inversion method to derive ∼300 new asteroid physical models (i.e., convex shapes and rotational states). We introduce several reliability tests that we use on all new asteroid mod- els. We investigate rotational properties of our MBAs sample (∼450 models here or previously derived by the lightcurve inversion), especially the spin vector dis- tribution. It is clear that smaller asteroids (D 30 km) have strongly anisotropic spin vector distribution even when we remove the bias of the lightcurve inversion, the poles are clustered towards ecliptic poles. We explain this anisotropy as a re- sult of non-gravitational torques (YORP effect) acting on these objects, because without accounting these torques, we were not able to create such anisotropic dis- tribution by our model of the spin evolution. We also estimate sizes for 41 and 10 asteroids by scaling their models to fit the adaptive optics profiles and occultation observations, respectively.
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Media portrayal of Andrej Babis before the elections to the Chamber of Deputies of Parliament of the Czech republic in 2017
Hanus, Josef ; Hanzal, Jaromír (advisor) ; Lütke Notarp, Ulrike (referee)
The Master's thesis focuses on the creation of the media image of one of the most distinctive and controversial current Czech politicians, Andrej Babiš, in the period prior to the 2017 general elections in the Czech Republic. The media image building process is viewed through the lens of agenda-setting theory in major daily newspapers and the Facebook page of ANO, Mr. Babiš's party. The aim of the thesis is to use mixed research to describe the creation of Mr. Babiš's media persona and to determine whether media discourse was influenced by intermedia agenda-setting process. In the quantitative analysis of this research, the volume and content of topics established by Mr. Babiš's media activity will be explored. The topic with the greatest relevancy and frequency will be used to determine the framework of the creation of Mr. Babiš's media image, discuss to what extent Mr. Babiš managed to control the outcome, and what role was played by the intermedia agenda-setting process. Keywords Andrej Babis, agenda-setting, daily newspapers, Facebook, media image building
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Utilization of Cone Beam CT for Reconstruction of Dose Distribution Delivered in Image-guided Radiotherapy of Prostate Carcinoma - Bony Landmark Setup Compared to Fiducial Markers Setup
Paluska, Petr ; Hanuš, Josef (advisor) ; Doležel, Martin (referee) ; Podzimek, František (referee)
The purpose of my doctoral thesis was to compare two different styles of prostate image- guided radiotherapy: bony landmark (BL) setup vs. fiducial markers (FM) setup. Twenty-nine prostate patients were treated with daily BL setup and 30 patients with daily FM setup. Delivered dose distribution was reconstructed on cone-beam CT (CBCT) acquired once a week immediately after the alignment. Target dose coverage was evaluated by the proportion of the CTV encompassed by the 95% isodose. Original plans employed 1 cm safety margin. Alternative plans assuming smaller 7 mm margin between CTV and PTV were evaluated in the same way. Rectal and bladder volumes were compared with initial ones. While the margin reduction in case of BL setup makes the prostate coverage significantly worse (p = 0.0003, McNemar's test), in case of FM setup with the reduced 7 mm margin, the prostate coverage is even better compared to BL setup with 10 mm margin (p = 0.049, Fisher's exact test). Moreover, partial volumes of organs at risk irradiated with a specific dose can be significantly lowered (p < 0.0001, unpaired t-test). Reducing of safety margin is not acceptable in case of BL setup, while the margin can be lowered from 10 mm to 7 mm in case of FM setup.
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A comparison of the marketing communication of the Czech Olympic Committee and the Czech Paralympic Committee in 2014 and proposal of their mutual cooperation
Hanus, Josef ; Halada, Jan (advisor) ; Šesták, Zdeněk (referee)
The goal of this work is to propose efficiency improvements in marketing cooperation of the Czech Olympic Committee and the Czech Paralympic Committee on the grounds of the comparison of their marketing communication. Special focus is given to the goals of equal conditions for non-handicapped and handicapped sportsmen at all performance levels. I used the descriptive analysis in this work and as a result I propose specific communication solutions that should lead to fulfilling the goal of the work. On the grounds of the comparison and analysis of the communication of mentioned subjects I expect that a close cooperation can lead to savings in marketing as well as a growth of the supporters base, improvement in media coverage and increased revenues as a result of such changes.
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Trends and Significance of the Migration of Foreign Students mainly from non-EU Countries in the Czech Republic and Europe.
Zábranská, Agáta ; Šatava, Leoš (advisor) ; Hanuš, Josef (referee)
in English The diploma Thesis "Trends and Significance of the Migration of Foreign Students mainly from non-EU Countries in the Czech Republic and Europe." discusses the phenomenon of migration for study purposes from non-EU countries (mainly Russia, Ukraine and Bosnia and Herzegovina) in the Czech Republic. The percentage of immigrants coming to study in Czech Republic has been growing and it constitutes an important tool for a positive development of the international cooperation. The aim of this work is to describe and analyze, based on the questionnaire method and specialized texts, the reasons for the choice of this type of migration, underling the administrative, economic and social issues that might be involved. Furthermore the objective is to evaluate the participation of qualified foreigners in the Czech labor market as well as to determine, presenting specific cases collected by a qualitative method, the human, cultural and social added value that they might gain by being awarded with an European diploma. Finally, in order to study the phenomenon from an anthropological perspective, the study attempts a comparative analysis of the academic mobility as a mean of temporary circular migration, enabling an optmized prediction of the current trends and tendencies while considering the issues of...
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Asteroid Models from Sparse Photometry
Hanuš, Josef ; Ďurech, Josef (advisor) ; Harris, Alan (referee) ; Tanga, Paolo (referee)
We investigate the photometric accuracy of the sparse data from astrometric surveys available on AstDyS. We use data from seven surveys with the best accu- racy in combination with relative lightcurves in the lightcurve inversion method to derive ∼300 new asteroid physical models (i.e., convex shapes and rotational states). We introduce several reliability tests that we use on all new asteroid mod- els. We investigate rotational properties of our MBAs sample (∼450 models here or previously derived by the lightcurve inversion), especially the spin vector dis- tribution. It is clear that smaller asteroids (D 30 km) have strongly anisotropic spin vector distribution even when we remove the bias of the lightcurve inversion, the poles are clustered towards ecliptic poles. We explain this anisotropy as a re- sult of non-gravitational torques (YORP effect) acting on these objects, because without accounting these torques, we were not able to create such anisotropic dis- tribution by our model of the spin evolution. We also estimate sizes for 41 and 10 asteroids by scaling their models to fit the adaptive optics profiles and occultation observations, respectively.
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Asteroid Models from Sparse Photometry
Hanuš, Josef
We investigate the photometric accuracy of the sparse data from astrometric surveys available on AstDyS. We use data from seven surveys with the best accu- racy in combination with relative lightcurves in the lightcurve inversion method to derive ∼300 new asteroid physical models (i.e., convex shapes and rotational states). We introduce several reliability tests that we use on all new asteroid mod- els. We investigate rotational properties of our MBAs sample (∼450 models here or previously derived by the lightcurve inversion), especially the spin vector dis- tribution. It is clear that smaller asteroids (D 30 km) have strongly anisotropic spin vector distribution even when we remove the bias of the lightcurve inversion, the poles are clustered towards ecliptic poles. We explain this anisotropy as a re- sult of non-gravitational torques (YORP effect) acting on these objects, because without accounting these torques, we were not able to create such anisotropic dis- tribution by our model of the spin evolution. We also estimate sizes for 41 and 10 asteroids by scaling their models to fit the adaptive optics profiles and occultation observations, respectively.
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Origin of asteroids in the 2:1 mean-motion resonance with Jupiter
Chrenko, Ondřej ; Brož, Miroslav (advisor) ; Hanuš, Josef (referee)
Asteroids located in the 2:1 mean-motion resonance with Jupiter are classified as stable (called Zhongguos), marginally stable (called Griquas) and unstable (called Zulus) according to their dynamical lifetime. The stable asteroids reside in two separate stable islands in the pseudo-proper element space. In this thesis, we update the resonant population on the basis of up-to-date observational data and we determine orbital and physical properties of the resonant population. Using collisional models, we demonstrate that the observed Zhongguos and Griquas might be up to 4 Gyr old, thus their origin might be related to the planetary migration. Performing dynamical N-body simulations, we test two hypotheses of the origin of the long-lived population: the primordial population scenario, and the asteroidal capture scenario. Our results imply that the resonant population is not primordial but it was rather formed by the asteroids captured from an asteroidal family located in outer main belt.
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