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Semantic segmentation using support vector machine classifier
Pecha, Marek ; Langford, Z. ; Horák, David ; Tran Mills, R.
This paper deals with wildfire identification in the Alaska regions as a semantic segmentation task using support vector machine classifiers. Instead of colour information represented by means of BGR channels, we proceed with a normalized reflectance over 152 days so that such time series is assigned to each pixel. We compare models associated with $\mathcal{l}1$-loss and $\mathcal{l}2$-loss functions and stopping criteria based on a projected gradient and duality gap in the presented benchmarks.
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Diversity and abundance of birds in 3D space of Žofínský prales primary forest
Kučerová, Eliška ; Hořák, David (advisor) ; Korňan, Martin (referee)
Bird species are specialized in diverse types of environments. Considering for example forest species, this does not mean that all species inhabit the same ecological niches. Some species occupy undergrowth while others prefer treetops. Some birds are bound to clearings and other gaps in forest cover, and other species require old trees with cavities. Primary Central European mixed forest is not a homogenous environment. But, on small spatial scales, the environment is very heterogeneous. We get an unprecedented variety of habitats especially when including the forest vertical dimension, which birds use much more than it is usually considered in studies. This diploma thesis describes in detail the bird assemblage in the Czech oldest nature reserve NPR Žofínský prales in which vegetation research is currently in progress. However, research dealing with bird mapping in forests still rarely consider the vertical dimension of the environment. Most bird censuses focus on the diversity of species at a site but usually do not include abundance of individual species. I, therefore, focused on a detailed mapping of the bird community on a 50-hectare area in NPR Žofínský prales. During the census, each bird and each bird's exact position in the 3D space of the forest were recorded. Special attention is paid...
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The activity of Police of Czech Republic in the South Bohemia in case of finding the booby trap explosive system
HORÁK, David
This diploma thesis deals with the readiness of security forces, especially the patrol service of the Police of the Czech Republic of the South Bohemian Region, which is most likely to be the first to find a suspicious object (eg a booby-trapped explosive system) and must solve the situation so as not to cause life and the health of citizens or property. The thesis defines the basic concepts and characteristics of booby-trapped explosive systems and the procedures for the disposal of these systems.
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Bird conservation status along a successional gradient in abandoned military areas
Bystřický, Václav ; Reif, Jiří (advisor) ; Hořák, David (referee)
Populations of open habitat bird species has significantly decreased in the Czech Republic during the last decades due to a number of negative factors, such as urbanization and intensification of agriculture. Due to the deterioration of the quality of these biotopes, a number of bird species (not only those of conservation importance) were forced to look for remaining fragments of favorable habitats, which are, for example, abandoned military training areas. The attractiveness of these territories lies primarily in their former closure for military purposes, which has protected these areas against these negative factors. In addition, army's activities created a heterogeneous landscape characterized by a mosaic of biotopes in different stages of vegetation succession - from bare ground, through grasslands, sparse scrubland, dense scrubland to the forest. However, the significance of abandoned military training areas for birds requires deeper investigation. The main goal of this thesis was to describe conservation importance of bird communities in individual biotopes along the successional gradient, for which a survey of 42 abandoned military training areas was used. The results of my work show that the most declining, endangered and protected species of birds sought out early successional habitats...
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Impacts of deforestation of west African mountains on biodiversity
Stříbrská, Eliška ; Hořák, David (advisor) ; Reif, Jiří (referee)
The high rate of deforestation is a global problem with negative impacts on species biodiversity and it also contributes to global and local climate changes. This problem is much more urgent in hotspots of biodiversity and endemism like west African mountains. Moreover, these locations are now recognized as the most fragmented and the most deforested mountains on the African continent. Impacts on local organisms is mostly negative. The organisms are facing habitat loss and the inability to migrate between the isolated regions. The bond between associated animals and plants, that are life depend on each other, is being broken and the whole ecosystem is being changed. In general, the ecosystem is less stable and all these changes make deforestation a chain reaction. Although there are some positive impacts on the biodiversity too, it does not influence the endemic species. It has more positive consequences for the generalist species occupying wide range of habitats and utilizing various food resources. Local communities are also facing the impacts of the ecosystem changes, their lives are negatively influenced by longer and more intensive periods of drought, landslides and they are not able to rely on the supply of the forest products. To be able to change current situation, financial support and...
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Evolution of endemism of mountain animal species
Švihálková, Tereza ; Munclinger, Pavel (advisor) ; Hořák, David (referee)
The mountain islands, isolated habitats surrounded by a distinct lowland environment, are home to a variety of endemic animal species. These hot-spots of biodiversity and endemism can be found mainly in tropical areas. Thus, the occurrence of endemics partially corresponds to the general macro-ecological rules of biogeography. For a more specific explanation of the origin and evolution of mountain animal species, we usually proceed from two theories - vicariate and dispersion. The validity of these theories varies in relation to taxon, locality, and evolutionary past, so it is difficult to generalize them globally. This bachelor thesis summarizes the prerequisites for the occurrence of endemic species and knowledge from some world- important mountain localities with a large number of endemic animals.
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Seasonality in reproduction and abundance of birds in African savannas
Kučminová, Veronika ; Hořák, David (advisor) ; Remeš, Vladimír (referee)
Seasonality of climate is a crucial factor that determines the existence of African savannas. Especially, the rainfall seasonality is a key factor in the abundance and reproduction of bird species of the savannas. Precipitation determines the timing of reproduction directly, but mainly indirectly through the influence of the environment, phenology, and productivity of plants. The vegetation determines the availability of resources and shelters. However, the widespread distribution of the savannas across the continent means that the seasonality and consequently the environment varies considerably from one area to another due to the different timing, size, and duration of wet and dry seasons. Breeding, as well as the abundance of savanna birds, is clearly influenced by the availability of food, which is determined by seasonal rainfall. For most species, the rainy season is an ideal time for reproduction, but there are also other groups of birds, that prefer a dry season for breeding and nesting. The birds must cope with unfavourable conditions outside the breeding season or leave their breeding areas. The abundance of birds in savannas is also significantly affected by the presence of palearctic migrants. Migration is therefore an important factor of the seasonal abundance of the savanna avifauna....
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Food competition between waterbirds and fish
Bečvář, Viktor ; Hořák, David (advisor) ; Musil, Petr (referee)
Food competition between waterbirds and fish can be a crucial factor in todays wetland ecosystems. In certain situations it can be decisive if a specific site is still suitable for waterbirds or not. Large aquatic invertebrats are often shared food resource. Situations where specific waterbirds and fish compete for this resource were described in many wetland habitats. Fish are often much more effective in acquiring food to the point when this relationship can be described as asymetrical competition. The level of competition can be also influenced by various envirometal factors or different attributes of waterbird and fish populations. The knowledge obtained by studing this relationship can be then used in management of protected areas and comercially used waterbodies.
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Migratory behaviour of Czech blackcaps (Sylvia atricapilla)
Valečková, Dominika ; Hořák, David (advisor) ; Procházka, Petr (referee)
Avian migratory behaviour has changed recently due to several factors including climate change. In many species of birds their wintering areas have become to move and their migratory paths have shortened. The Blackcap (Sylvia atricapilla), species with migratory divide located in the Czech Republic, established a new migratory path and a new wintering area on The British Isles within a few generations. This shorter route provides many benefits such as sooner return to breeding ground and occupying better territories, and lead to rapid growth of the number of individuals wintering there. Other changes in morphology (e.g. length of wings and bill, colouring etc.), ecology and ethology (e.g. earlier nesting accompanied by assortative mating etc.) are linked to this new migratory behaviour. The aim of this thesis is to analyse the ringing and mist netting data and compare the results with the published data, confirm existence of this migratory behaviour in our breeding population and obtain support of some related hypotheses. My results confirmed the existence of this new behaviour in our breeding population of blackcaps. During the period 1934-2020 Czech blackcaps changed their migratory behaviour in favour of a new route to The British Isles. Number of wintering blackcaps in these areas started to...
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