|
|
Detekce graffiti tagů v obraze
Fischer, Martin ; Kodym, Oldřich (oponent) ; Špaňhel, Jakub (vedoucí práce)
Cílem této práce je porovnat různé přístupy počítačového vidění se záměrem automatické detekce graffiti tagů v obraze. Za tímto účelem byly v řešení použity modely založené na neuronových sítích. V práci byly otestovány jak osvědčené detekční modely, tak i modely experimentální. U nejpřesnějšího z nich (Faster R-CNN) bylo dosaženo přesnosti 83% mAP, což poukázalo na vhodnost těchto modelů při řešení otázky detekce tagů.
|
|
| |
|
| |
|
|
Towards a combining of remote sensing and in situ evapotranspiration measurements
Fischer, Milan ; Jurečka, František ; Anderson, M. ; Hain, C. ; Pozníková, Gabriela ; Hlavinka, Petr ; Orság, Matěj ; Lukas, V. ; Žalud, Z. ; Trnka, Miroslav
This study provides preliminary results from combining in situ Bowen ratio energy balance (BREB) and\nevapotranspiration (ET) measurements techniques with physically based remote sensing ET estimates determined\nby the Atmosphere-Land Exchange Inverse (ALEXI) model. Evapotranspiration measurements\nand ALEXI estimates were analysed in an agricultural area close to Polkovice, Czech Republic during 2015,\nwhen a drought spell and intensive heatwaves appeared in the country. The BREB system was monitoring a\nwinter wheat (Triticum aestivum L.) field (~26 ha) while the ALEXI pixel (~5 km resolution) covered a wide\nrange of crops, including mainly winter wheat, spring barley, and winter rape. The study results showed that,\nalthough the applied methods work at different spatial scales (field vs. landscape), their combination can provide\nfurther insights into ET at both scales. For instance, such approach can be used to identify whether a specific\necosystem investigated in situ contributes to cooling or warming of the landscape.
|
|
|
Application of multispectral remote sensing indices for sensing indices for estimating crop yields at field level
Jurečka, František ; Lukas, Vojtěch ; Hlavinka, Petr ; Semerádová, Daniela ; Fischer, Milan ; Žalud, Zdeněk ; Trnka, Miroslav
Remote sensing can be used for yield estimation prior to harvest and can replace or complement classical\nways of estimating crop yields. This study was undertaken in Polkovice, located in the Czech Republic’s\nHaná region. For 2015 and 2016, two data sets of satellite imagery were used: the Moderate Resolution\nImaging Spectroradiometer and the Landsat 8. Vegetation indices from satellites were compared with crop\nyields at the level of land blocks. Winter wheat and spring barley yield data, representing crops planted\nover the analysed period, were used for the comparison. The results of the index–yield comparison showed\nthat vegetation indices from remote sensing data provide reliable information for yield estimation prior to\nharvest. Indices are also able to evaluate the spatial variability of a crop within the field. The results showed\nthat remote sensing data need to have detailed spatial resolution in order to provide reasonable information\nabout yield at such a detailed level.
|
|
|
Potential of flux-variance and surface renewal methods for sensible heat flux measurements at agricultural and forest surfaces
Fischer, Milan ; Katul, G. ; Pozníková, Gabriela ; Noormets, A. ; Domec, J.-C. ; Trnka, Miroslav ; King, J.
Two alternative micrometeorological methods, flux-variance (FV) and surface renewal (SR), based on\nmeasurements of high-frequency temperature fluctuation and Obukhov length stability parameter, were\ntested against eddy covariance (EC) sensible heat flux (H) measurements. The study was conducted at\nthree sites representing agricultural, forestry, and agroforestry systems. In terms of measurement setup,\nthese sites represented surface, roughness, and canopy top layer, respectively. As expected, the best match\nof all the methods was in the surface layer, whilst it was poorer in the roughness and canopy sublayers.\nSystematic deviation from EC across all three investigated surfaces was within 16% and 8% for FV and SR,\nrespectively. While FV resulted in higher correlation with EC measurements (0.93–0.98 vs. 0.89–0.97),\nSR provided less systematic biases (1.02–1.08 vs. 0.94–1.16). In general, both FV and SR provided slightly\nhigher H as compared to EC. We suggest that parallel deployment of FV and SR is useful, as both methods\nrequire the same instrumentation yet they are based on sufficiently different theories. Therefore, the agreement\nbetween FV and SR increases confidence in the results obtained and vice versa.
|
|
|
Konstrukce číslicově řízených obráběcích strojů
Fischer, Michael
Bakalářská práce se zabývá číslicově řízenými obráběcími stroji. První část práce se zaobírá charakteristickými znaky a konstrukcí obráběcích strojů, kde jsou stručně popsány jejich jednotlivé části. Dále se zaměřuje na základní rozdělení číslicově řízených obráběcích strojů a jejich řezné podmínky. Druhá část práce se zaobírá automatickou výměnou nástrojů, vznikem tepla, chlazením a mazáním číslicově řízených obráběcích strojů. V závěru bakalářské práce je popsán současný stav obráběcích strojů a využití číslicového řízení v ostatních odvětvích.
|
|
|
Essays on Monetary Integration, Inflation, and Trade Competitiveness in Transition Countries
Uzagalieva, Ainura ; Cukrowski, Jacek (vedoucí práce) ; Fischer, Manfred (oponent) ; Ratfai, Attila (oponent)
This dissertation contains three essays focused on macroeconomic issues in the Commonwealth Independent States (CIS). The aim of the first essay is to analyze the possible impact of planned monetary integration on public sector revenues from seigniorage in Belarus, Kazakhstan and Russia. Using the concept of total gross seigniorage, the main sources and uses of the central bank revenues in these countries is investigated. Special attention is given to the role of seigniorage revenues in financing public sector expenditures. Amounts of yearly transfers from central banks to the state budget in Belarus, Kazakhstan and Russia are evaluated, and the size of potential gains and losses in seigniorage revenues under different scenarios of monetary integration are estimated. The second paper focuses on the question of how labor market regulations can affect a country's competitive position in international trade and international trade patterns. The analysis shows that differences in labor market flexibility between countries affect their competitive positions in international markets and can serve as an independent cause of international trade. It is argued that an increase in labor market flexibility may change the relative price of goods within the country making it more competitive in international...
|
|
| |
|
|
The Bowen Ratio/Energy Balance method and detailed temperature profile measurements to improve data quality control
Pozníková, Gabriela ; Fischer, Milan ; Orság, Matěj ; Trnka, Miroslav ; Žalud, Zdeněk
Water plays a key role in the functionality and sustainability of ecosystems. In light of predicted climate change, research should focus on the water cycle and its individual components. The main component of water balance driving water from ecosystems is evapotranspiration (ET). One standard method for measuring ET is the Bowen Ratio/Energy Balance (BREB) method. It is based on the assumption that water vapour and heat are transported by identical eddies with equal efficiency. When using the BREB method, we assume that the profiles of temperature and air humidity are ideally logarithmic or at least consistent. Since the BREB method is usually based on measurements of temperature and humidity at only two heights, it is difficult to verify whether this assumption has been fulfilled. Potential profile inconsistencies are more likely for temperature because the sensible heat flux changes its sign more often and negative latent heat flux is not physically possible during positive sensible heat flux. We therefore conducted a field experiment using a 4-mhigh measurement mast with 20 thermocouples for detailed measurement of air temperature profiles above different covers, e.g. grassland, spring barley, and poplar plantations. Our main objective was to investigate the basic assumptions of the BREB method, i.e. the temperature profile’s consistency under various weather conditions. To be more specific, we aimed to investigate whether inflexion points occurred within the temperature profile and if so when.
|
host ::
RSS.