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Image Reconstruction in Electrical Impedance Tomography through Multilayer Perceptron
Kouakouo Nomvussi, Serge Ayme ; Mikulka, Jan
This study introduces a novel image reconstruction algorithm designed to excel in challenging scenarios with noisy datasets. Comparative evaluations against established methods, the Total Variation technique and the Gauss-Newton algorithm, are conducted using key performance metrics including the correlation coefficient and structural similarity index. The Results demonstrate that the proposed algorithm displays variable performance in noise-free data compared to Total Variation but consistently outperforms it in the presence of noise. Furthermore, when contrasted with the Gauss-Newton algorithm, the proposed method consistently exhibits superior outcomes, particularly in scenarios involving noisy datasets, where the Gauss-Newton algorithm faces limitations. This study underscores the robustness of the proposed algorithm in noisy conditions, suggesting its potential for applications where accurate image reconstruction is critical.
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Price Elasticity of Electricity Revisited: A Meta-Analysis
Šikl, Vojtěch ; Havránková, Zuzana (advisor) ; Petit, Mathieu (referee)
Despite a plethora of empirical research on electricity demand, results regard- ing estimated price elasticities persist to be inconclusive. Our meta-analysis synthesizes 4521 estimates from 413 studies to explore the presence of publi- cation and endogeneity bias. We code for over 100 variables to quantify the response of electricity consumers to price shifts. The price elasticity of electric- ity is inelastic and the short-run elasticity sample average of -0.231 is double (in magnitude) the short-run elasticity corrected for publication bias, which is -0.116. The long-run elasticity adjusted for publication bias is -0.303. We conclude that experimental studies, while also su ering from publication bias, report unbiased elasticities of -0.07. Our thesis also confirms a significant occur- rence of p-hacking across multiple specifications. By employing Bayesian model averaging, we explore the heterogeneity among reported elasticities, finding that factors such as decreasing tari s, demographics and fuel usage controls, daylight hours and number of citations critically influence the variability in findings. The average and marginal price of electricity and time of use tari s play a negligible role in explaining the di erences in estimated elasticities. JEL Classification D01, Q40, Q49, C11 Keywords...
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Evaporation from the water surface
Novotný, Eduard ; Šobr, Miroslav (advisor) ; Šuhájková, Petra (referee)
Evaporation and evapotranspiration are significant components of the hydrological cycle. Accurate measurement or calculation of evaporation is essential for studies of water resource development and management, as well as for efficient crop irrigation in agriculture. Throughout history, many models have been developed to calculate potential evapotranspiration based on various meteorological parameters. The accuracy of these models needs to be determined by comparing them with measured evaporation values obtained from an evaporation pan. In this study, 7 models for calculating potential evapotranspiration or evaporation from a free water surface based on air temperature are compared with evaporation measured by the VYPAR-1200 evaporation pan during the evaporation season 2021 at the Vrchlice meteorological station. The most accurate results were obtained with the models presented by Oudin et al. (2010) and Šuhájková et al. (2019), with RMSE values of 1.061 and 1.105 mm/day and MBE of 0.554 and 0.303 mm/day. Even so, the deviations are quite significant and for more accurate calculation of evaporation for the Vrchlice region, parameterization of these models would be necessary. Key words evaporation, water surface, evaporimeter, meteorological station Vrchlice
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Design of production technology for cone rotary mechanism
Knápek, Merlin ; Chladil, Josef (referee) ; Sliwková, Petra (advisor)
Bachelor's thesis is focused on design of production technology for protype of rotary bearing for children's excavator, which consists of conical pin and conical bushing. Specified production volume is 1 piece. Material was changed for both components to stainless steel AISI 303. From concidered technologies was chosen machining, specifically machining on conventional machines. Individual methods required for production were analyzed, including turning, milling, grinding, drilling and threading. Original design was modified so that only lathe and drilling machine have to be used for machining. Based on machines and chosen method were selected suitable tools, gauges and aids for production and was developed manufacturing process also acompanied by operational instructions.
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Validization of diagnostic methods in PTSD
Vágnerová, Anna ; Preiss, Marek (advisor) ; Heider, David (referee)
With this work, I became involved in an ongoing project of tool validation for measuring psychological trauma within the activities of the National Institute of Mental Health - Validation of tools for measuring psychological trauma. The aim of this thesis was to collect data from a clinical population with posttraumatic stress disorder (PTSD) and compare it with the results of diagnostic methods in the general population (N=303). The research clinical sample consisted of 31 respondents who, based on diagnostic criteria for PTSD diagnosis according to DSM-5, were divided into two research groups - with a probable PTSD diagnosis (N=17) and without a probable PTSD diagnosis (N=14). In this work, the results of three research groups were compared using the PTSD Checklist 5 method, which assesses the level of traumatization, and the Life Events Checklist-5 method, which examines the frequency of experienced traumatic events. At the same time, measurement of depressive and anxious symptoms of all participants was conducted to assess convergent validity. The results of statistical analysis showed that the PCL-5 method proved to be valid. The group with a probable PTSD diagnosis achieved statistically significantly higher values than the general population group, even in the results of methods measuring...
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The family house with residential attic
Chalupská, Eva ; Krejčová, Lenka (referee) ; Krupicová, Jana (advisor)
The aim of my thesis was a proposal of new built family house. The house will be located in the land in Třebenice on plot No. 303/1. There is no cellar in the house, but there are two main storey, the second storey is a habitable attic. It has a gable roof. The Ytong system was used for the construction proposal of the house.
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Appliances for solid fuel for heating
Lackovič, Roman ; Hrnčířová, Michaela (referee) ; Štelcl, Otakar (advisor)
Bachelor's thesis "Appliances for solid fuel for heating" aims on the issue of emission measurement for solid fuel boilers. The first part is a theoretical introduction, where solid fuels are described, following are the types of appliances, which are powered by solid fuels. There are described legislation related to emission limits and principles of devices used for measururing emissions of solid fuel appliances at the end of the theoretical part. The second part is the attention devoted to description of measurement, that we have done, calculation of efficiency and emissions for measurement. Lastly, there is specified emission class to which the boiler, according to measurement, belongs.
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Working efficiency of boilers
Rejsa, Vojtěch ; Horák, Petr (referee) ; Počinková, Marcela (advisor)
This work deals with the determination of the operational efficiency of solid fules boilers for their inclusion in the relevant emission class according to ČSN EN 303-5. Two steel boilers of the same manufacturer, type and performance but of different ages, were measured. The experimental measurments in the real operation of the boilers were carrien out during the combustion of two types of fuels, namely brown coal and spruce wood.The operational efficiency of the monitored sources was calculated from the measured data using both direct and undirect methods. The found efficiency of the boilers corresponds to the expected values, due to their construction, age and the way of using individual components and regulations. In the project part of this work there is a proposal of heating of the family house for the condition of the building before and after the insulation. The calculation was made for the solid fuel boiler and heat pump. The building is heated by radiators and floor heating. The design of the whole system, technical report and project documentation were prepared for each variant.
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Gasification boilers
Votoupal, Adam ; Štelcl, Otakar (referee) ; Baláš, Marek (advisor)
This bachelor thesis deals with the principle of the operation of gasification boilers which have small capacity (up to 500 kW) and which have manual fuel supply. The first part of the thesis consists of the literature review and describes the basic distribution of the boilers according to the type of fuel used and according to the basic principle of their operation. The gasification boilers are described in more detail in this part of the bachelor thesis. The second part of the thesis includes a description of the emission measurements which were performed on a selected test boiler (Damat Pyro 20 G) and the evaluation of the results of these measurements. The measurements were conducted in accordance with the ČSN EN 303-5 according to which the boiler was included into the particular emission class.
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