National Repository of Grey Literature 973 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Řízení integračních soustav
Meduna, Jakub
This thesis describes modern methods of controlling integration systems that are commonly found in practice all around us. The aim of this thesis was to select a suitable PID controller with two degrees of freedom to control these systems and to compare the results with classical PID regulation. The evaluation was based on comparing several typical criteria of quality. The results of the simulation experiments show that the regulation by the controller with two degrees of freedom, with certain requirements for the regulation way, does not always come out as a better option for controlling integration systems. The thesis concludes with a recommendation for the selection of a controller with two degrees of freedom and a recommended procedure for the selection of its parameteres.
Simulation of processes predicted by theory of frozen plasticity
Nekola, Ondřej ; Flegr, Jaroslav (advisor) ; Ponížil, Petr (referee)
The question of the tempo of evolution is amongst the oldest conundrums in evolutionary biology and has not been satisfactorily answered yet. One of the attempts to do so is the frozen plasticity theory, which postulates that a sexually reproducing species is only capable of evolution within short periods of time after its genetic polymorphism decreases e.g. as a consequence of peripatric speciation. In the longer periods of evolutionary stasis, its evolution is limited by frequency- dependent selection and pleiotropy. In this work, I have produced an open source software simulating the respon- ses of populations of sexually reproducing individuals to varying environmental conditions. Using this software, I simulated evolution of populations with different probabilities of arising of alelles affecting more phenotypic traits and frequency- dependent selected alleles that have opposing phenotypic effects when present at the locus in one copy, respectively two copies. I observed trends predicted by the theory of frozen plasticity: slower adap- tation to instant environmental changes, lower achieved fitness and more frequent extinctions of populations with higher portions of investigated types of alleles, but only with low effect sizes and without statistical significance. For future research, it would be desirable...
Freshman chemistry student teachers' ability to balance chemical equations: performance, procedure and the effect of applet use
Hamerská, Lucie ; Rusek, Martin (advisor) ; Bílek, Martin (referee)
The research undertaken for this master thesis mapped the students' ability to evaluate chemical equations. Three main aspects were investigated: success in balancing equations, procedures and the use of the applet environment. The research sample consisted of 11 freshmen chemistry student teachers. Eye-tracking in combination with retrospective think-alouds and interviews were used to analyze the students' procedures. This thesis builds on the author's previous bachelor thesis and uses findings from the evaluation of pre-tests that addressed basic chemistry concepts in the area of particulate nature of matter and the ability to work with chemical representations with a special focus on chemical equations. The results of the research highlight the gap between conceptual understanding of the topic of chemical equations and algorithmic ability to balance chemical equations. Only five students out of 11 achieved the same results in the individual parts of the research. The achievement of more than half of the students was below what is expected at the upper secondary level. Analysis of the procedures identified problems in the students' equation balancing that may have affected their success - basic mathematical skills, omitting the final check, having to use higher values of stoichiometric...
Price Dynamics of Automated Market Makers: Simulation-based Approach
Kubal, Jan ; Krištoufek, Ladislav (advisor) ; Čech, František (referee)
The aim of this thesis is to analyze the price dynamics implied by the Automated Market Makers used by Decentralized Exchanges of DeFi and to verify the presence of some behavioral patterns with a simulation-based approach. Returns from 10 representa- tive token pairs were collected over a 15-day period and their properties were compared against traditional stylized facts. A simulation that reproduces the observed price pro- cess was then developed, mimicking the realized swap orders and utilizing the constant product pricing equation of AMMs, incorporating two additional features that implement periods of hype and herding behavior. Analysis of the empirical data revealed that AMM token returns follow the stylized facts most of the time, with their distributional properties, autocorrelation patterns, and volatility clustering. No consistent trend in the leverage effect was found among tokens. The simulation then confirmed that a basic AMM model is sufficient in producing prices with similar returns, showing that this method of transaction settlement is robust and generates the expected price dynamics. The two behavioral mechanics added further increased the similarity between real and simulated return characteristics, indicating that the effects may also influence the actual price formation process. 1
Study of Inserting Hardware Trojans into Processors
Šviková, Johana ; Šimek, Václav (referee) ; Růžička, Richard (advisor)
This bachelor's thesis focuses on a specific aspect of cybersecurity known as hardware trojans, which are insidious attacks integrated directly into electronic components. The work begins with an analysis of the architecture and function of hardware trojans, examining their various types and classifications, and exploring methods for their detection and prevention. Furthermore, the thesis investigates how these attacks can impact compromised devices and how they can pose serious security risks. This thesis contains a design and implementation of a Trojan horse for a simple processor.
The Role of Charge Regulation in Weak Polyampholytes
Lunkad, Raju ; Košovan, Peter (advisor) ; de Sousa Dias, Rita (referee) ; Gonzalez, Jose Luis Garces (referee)
A weak polyampholyte is a polymer that consists of both acid and base groups along the chain. In aqueous solutions, these groups dissociate in a certain pH range, leading to a dramatic change in the overall charge of the polyampholyte from positive to negative as the pH increases. The ability of weak ampholytes to switch their charge in response to changes in pH makes them useful in various applications. Despite the considerable research on weak polyampholytes, the understanding of some aspects is still insufficient. To address this, I systematically investigated the charge regulation of weak polyam- pholytes, specifically peptides, both in solution and during their interaction with polyelectrolytes. Furthermore, I also looked at the charge regulation of polyzwitterions. All these studies were carried out using a simple coarse-grained bead-spring model in Langevin dynamics simulations. In addition, I used the constant-pH ensemble to account for the ionization reactions of acid and base groups in the implicit solvent. Through our simulations, we made significant advancements in understanding how charges and the ionization states of acid and base groups in various peptides and polyzwitterions respond to pH changes. By comparing simulation results with the ideal results predicted by the...
Numerical analysis of stabilizer clamp forming process
Zbořil, David ; Petruška, Jindřich (referee) ; Kubík, Petr (advisor)
This thesis focuses on the simulation of the clamp forming process in order to better estimate the dimensions of the development and its effect on the resulting clamp geometry. In the first part of the thesis, a research is carried out that discusses the incremental theory of plasticity, which is important for understanding the material behaviour during forming. The next part is devoted to the cold forming problem and the factors affecting the forming process. This is followed by an introduction to the principles of the Finite Element Method (FEM) and the creation of a clamp forming simulation. The paper further analyses the partial problems encountered during the simulation and finally the simulation results obtained with an ideal and a real clamp are compared. This work contributes to a better understanding of the clamp forming process and allows more accurate estimates of the dimensions of the unwinding and the resulting clamp geometry.
Improving material flow by using a logistics train
Grepl, Radovan ; Urbanovský, Jan (referee) ; Zeizinger, Lukáš (advisor)
The main content of this master´s thesis is the analysis of the current state and the proposal an internal supply of assembly lines in the company Koyo Bearings s. r. o. This company specializes in the production of bearings mainly for the automotive industry. The supply of the lines operates on the principle of Mikl-run. The practical part focuses on creating a simulation model using the Plant Simulation simulation software from Siemens PLM Software. Based on the created model, several variants were proposed to optimize the loading of the packaging material. These variants were analyzed and evaluated.
Material flow concept of a production line supply
Sedláček, Petr ; Dorušáková, Kamila (referee) ; Zeizinger, Lukáš (advisor)
The content of this thesis is a research analysis of individual concepts in the field of corporate logistics with an emphasis on intra-company transport. In the practical part, the current state of the production line loading is evaluated and new variants of line supply are made on the of the given parameters. The work also includes the creation of simulation models of all variants in the Plant Simulation program and conclusions are drawn based on the data obtained.
Optimisation of punch tool for produce holes of bearing cage
Matail, Petr ; Jopek, Miroslav (referee) ; Peterková, Eva (advisor)
The thesis is focused on analysis of causes of blanking punch cracking, which is used for piercing holes of barrel bearing cages and designing of new construction solution by changing shape of blanking punch. Multiple variants of rounding shearing edge and chamfering shearing edge was designed. The current state and designed variants were analysed by simulation in Simufact Forming program. The variants were compared by shear force progress, equivalent stress, contact pressure in blanking punch and effective plastic strain in blank cage. According to mentioned criteria the best solutin with rounding shearing edge by 0,7 mm and chamfering face of blanking punch by 10° was chosen.

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