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Substrate-controlled nucleation of the magnetic phase transition in nanostructures
Hajduček, Jan ; Procházka, Pavel (referee) ; Uhlíř, Vojtěch (advisor)
Properties of the phase transition in iron-rhodium (FeRh) from the antiferromagnetic (AF) to ferromagnetic phase (FM) are largely affected by lattice defects in FeRh. Epitaxial layers of FeRh are grown on monocrystalline MgO (001) substrates. Surface atomic terraces of the substrate can induce defects in epitaxial layers and modify electronic and magnetic properties. In this thesis the effect of surface atomic terraces on the width and the hysteresis of the metamagnetic phase transition in FeRh thin layers and nanostructures is studied. The amount and character of defects in FeRh are also affected by mutual orientation of terraces and FeRh nanowires, which changes the number of discrete jumps in FM-AF transition. The nanowires have been fabricated by electron-beam lithography. FM domains in in FeRh have been observed by magnetic force microscopy and electrical transport properties of differently oriented nanowires have been studied by 2-probe measurements. Higher density of surface atomic terraces significantly increases the number of discrete jumps in the FM-AF transition.
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Vehicle Control via Reinforcement Learning
Maslowski, Petr ; Uhlíř, Václav (referee) ; Šůstek, Martin (advisor)
The goal of this thesis is a creation of an autonomous agent that can control a vehicle. The agent utilizes reinforcement learning that uses neural networks. The agent interprets images from the front vehicle camera and selects appropriate actions to control the vehicle. I designed and created reward functions and then experimented with hyperparameters setup. Trained agent simulate driving on the road. The result of this thesis shows a possible approach to control an autonomous vehicle agent using machine learning method in CARLA simulator.
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Robot Positioning Based on Sensor Measurements
Čakloš, Ondrej ; Uhlíř, Václav (referee) ; Rozman, Jaroslav (advisor)
The goal of this thesis is to create a program, that will be receiving measurements from robot's sensors, provide sensor fusion and estimate position of robot based on this fusion. For solving I used knowledge about probabilistic robotics, robotic operating system, information fusion, filtering especially extended Kalman filter and robot localization. I created an application of extended Kalman filter as a result. Filter listen to messages from robot sensors, providing a sensor fusion and estimating position of the robot in environment. Filter can receive measurements from multiple sources. The estimated states have proven themselves reasonably accurate for successful robot localization in space.
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Path Planning using Voronoi Graphs
Živčák, Adam ; Uhlíř, Václav (referee) ; Rozman, Jaroslav (advisor)
The main purpose of this bachelor thesis is to design and implement plugin for robot operating system, which will be used for path planning using Voronoi graphs. Path planning is executed in well known world, about which robot knows where obstacles are placed. Thesis contains overview of main concepts of robot operating system, description of Voronoi graphs and algorithms to construct them. In conclusion is placed comparison of implemented plugin for path planning with ROS integrated planners.
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Path Planning Algorithms Visualisation
Řepka, Michal ; Uhlíř, Václav (referee) ; Rozman, Jaroslav (advisor)
Finding of collision free path is central in creation of mobile, autonomous robot. Goal of this paper is to show the most important algorithms implementing such solutions. It also describes application that is being created to allow students experiment with these methods. For this purpose it uses library that was introduced by Jakub Rusnák in 2017, which means this is a continuation and possibly extension of his work.
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Magnetotransport properties of FeRh nanowires
Fabianová, Kateřina ; Dubroka, Adam (referee) ; Uhlíř, Vojtěch (advisor)
Železo-rhodium (FeRh) je látka procházející magnetickou fázovou přeměnou prvního druhu z antiferomagnetické (AF) do feromagnetické (FM) fáze, ke které dochází při zahřátí materiálu nad teplotu fázové přeměny nebo působením dostatečně velkého magnetického pole. Tato fázová přeměna je mimo jiné provázena výraznou změnou entropie, magnetizace a elektrického odporu, přičemž její tvar a poloha teploty přeměny je silně závislá na stechiometrii krystalu, na příměsích, tlaku a v případě tenkých vrstev na napjatosti vrstvy způsobené substrátem. Tato práce se zaměřuje na studium magnetotransportních vlastností drátů připravených z tenkých FeRh vrstev rostlých na substrátech indukujících různou napjatost vrstvy. Jedním z hlavních jevů studovaných v této práci je anizotropní magnetorezistance (AMR) projevující se změnou odporu pro různé natočení magnetických momentů v látce vůči směru elektrického proudu. AMR byla studována jak ve FM fázi, tak i v AF fázi FeRh. Byla změřena hodnota AMR ve vysokoteplotní FM fázi a objeveno neočekávané chování AMR ve zbytkové FM fázi v nízkoteplotním stavu. Dále byla pozorována výrazná závislost AMR na orientaci měřených segmentů vůči krystalografickým směrům FeRh.
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Proposal of online tracking system for racing
Uhlíř, Vojtěch ; Čábelka, Miroslav (advisor) ; Štefanová, Eva (referee)
Proposal of online tracking system for racing Abstract The bachelor thesis deals with an analysis of current web information technologies and their potential use for creating an online tracking system for racing. At the beginning, already existing live tracking systems are presented and evaluated. Current web geoinformation technologies are presented as well. In the practical part, a comparative analysis based on functional parametres is conducted with focus on Google Maps API, OpenLayers and Leaflet. The main outcome of the thesis is a complete proposal of a universal and modular system for online tracking of rally races which meets current requirements of motoring organisations. Keywords: web, GPS, Google Maps API, Leaflet, OpenLayers
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Path Planning for Robot Formations
Hornáček, Zdenko ; Uhlíř, Václav (referee) ; Rozman, Jaroslav (advisor)
Robotics has been experiencing great development in recent years. This development is due to constant technical progress and the effort to develop increasingly robust robots and to further develop co-operating groups of robots. These co-operating groups (robot formations) have many areas of use ranging from environmental mapping to search and rescue missions. This bachelor thesis deals with the design of the path planning algorithm for robot formations. It uses the already existing planning algorithm for single robot - the Dijkstra algorithm. Based on the path computed by this algorithm, the proposed algorithm will calculate the path for each robot so as to maintain the shape of the formation during its move to the goal.
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Anthropomorphization in Communication with Nonhuman Entities
Uhlíř, Vilém ; Stella, Marco (advisor) ; Markoš, Anton (referee)
In this thesis I pursue a critical summary of the so-called "talking animals" projects, wherein the researchers tried to train their animal subjects to perform "linguistic" feats. Considering both the fundamental dissilimarity of the projects and the uniformity of their results, I am lead to conclude that the shortcoming was that of the students - the animals, and not that of the teachers. Failure of the animal projects points mainly to the fact, that a core feature of language is missing in the pseudolinguistic feats of the animals that which is missing is the hierarchical recursive syntax. I conclude that no animal has had likely adopted the open, unbounded, hierarchically recursive system that allows us, quite literally, to express anything. Linguistic data that I considered indicates that language is most likely an inborn neural specialization of H. spaiens. All the available facts considered manage to show that the pseudolinguistic feats of the "talking" animals are most likely caused by a great plasticity of general cognition. General cognition has the capacity to virtually simulate (although imperfectly) certain aspects of human neural linguistic specialization. Neural linguistic specialization in H. sapiens is an evolutionary discontinuity, whereas the general cognition plasticity is...
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