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Trust and Reputation in Distributed Systems
Samek, Jan ; Návrat,, Pavol (referee) ; Šafařík,, Jiří (referee) ; Hanáček, Petr (advisor)
This Ph.D. thesis deals with trust modelling for distributed systems especially to multi-context trust modelling for multi-agent distributed systems. There exists many trust and reputation models but most of them do not dealt with the multi-context property of trust or reputation. Therefore, the main focus of this thesis is on analysis of multi-context trust based models and provides main assumptions for new fully multi-contextual trust model on the bases of them. The main part of this thesis is in providing new formal multi-context trust model which are able to build, update and maintain trust value for different aspects (contexts) of the single entity in the multi-agent system. In our proposal, trust value can be built on the bases of direct interactions or on the bases on recommendations and reputation. Moreover we assume that some context of one agent is not fully independent and on the bases of trust about one of them we are able to infer trust to another's. Main contribution of this new model is increasing the efficiency in agent decision making in terms of optimal partner selection for interactions. Proposed model was verified by implementing prototype of multi-agent system when trust was used for agents' decision making and acting.
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Is genetic diversity congruent with morphological diversity across the distributional range of the Melampyrum subalpinum group (Orobanchaceae)?
CHLUMSKÝ, Jan
Allozymes were used to assess the genetic structure of 27 populations of Melampyrum subalpinum group and an artificial pollination experiment was carried out to examine the possibility of autogamy. Genetic variation was generally congruent with the known morphological variation of the group. The results corresponded with the central-marginal concept. Allelic enrichment due to hybridization with M. nemorosum was observed in some Austrian populations. Czech and Slovak populations do not differ from Austrian populations. The high inbreeding coefficient and the pollination experiment do not contradict the possibility of autogamy.
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Distribution management in a large company (warehouse)
MICHALOVÁ, Jana
Distribution management in a large company. This Master´s Thesis examines the company Fruko-Schulz, s. r. o. This company has been making spirits. The goal is to map out the information and material flows toward the warehouse and from the warehouse. Subsequently, to analyze the current state of the company. Based on the information propose measures for improvement. In own work is described in detail and enterprise activities in a company. After ideas are designed to change. These proposals relate to distribution to the end customer through the gastronomical exhibitions and fairs. Other proposals are aimed at end users in the Russian market. Ideas for packaging or new products are designed, but is backed that do not make sense. Company Fruko-Schulz, s. r. o. sas a long tradition and reputation. But that's not enough, the competition is great and it isalso at a high level. The idea to focus on the Russian market is very good and there is great potential.
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How to prevent the proliferation of Legionella pneumophylis in hot water in the hospital Czech Krumlov
TUREK, Jan
This diploma thesis deals with microbiological quality of hot water in a hospital in Cesky Krumlov as well as hot water piping condition with respect to Legionella. It also deals with arrangements for improving the quality of hot water in this hospital. The subject and target of this thesis are the findings of the mentioned parameters based on own observations, technical documentation and analysis of warm water performed by an accredited laboratory. The hospital in Cesky Krumlov, the construction of which began in 1909, was built in 1911 as the 'Nemocnice Císaře Františka Josefa I.' As the time went by, new buildings were built up. The hospital was renamed to 'Všeobecná veřejná nemocnice' in 1942. In the following years the hospital expanded until the current condition. Water quality and presence of Legionella is a world-wide issue, which we must fight against. The thesis is divided into two parts. First, theoretical part, which includes both general and specific knowledge about Legionella, its health risks, the environment in which it occurs, possibilities of eliminating, suitability of the material for hot water pipes, gained in professional literature and a part of the Czech legislation dealing with public health protection, the law 'No. 258/2004 Coll.' in actual version and quality of drinking water and hot water. In the second, empirical part, I focus on the situation of the hospital in Cesky Krumlov from 2009 till 2015, concerning newly built boiler room and the whole distribution system of hot water regarding Legionella. Particularly I focused on materials used for ecologisation of the gas boiler room and materials used for hot water pipes and actual state of water distribution in individual buildings of this health care facility. I mentioned the analysis of the water samples performed by an accredited laboratory with corresponding technical documentation, which concerns the water distribution system, provided by the medical facility. I used secondary data analysis to evaluate these documents. Regarding the results from 2009 to 2015 the microbiological quality of warm water doesn't meet the limits defined in the Attachment No. 3 of the above mentioned law Order 252/2004 Coll. Limit value for colony forming units of Legionella is set to maximum of 100 CFU. In most of the samples this limit was exceeded by series of units up to hundred thousands of units. The last results in 2015 prove improvement of the unfavorable situation. In that year the analysis was tested three times. First in February, where the CFU units were 'only' in hundreds, with the top value of 550 CFU in the Postacute Care ward. Second analysis was performed in June that same year. Results were acceptable. The highest value was 64 CFU. Last analysis in the hospital was performed in December. Increased concentration of Legionella was again in the Surgery building. There were established of 1400 colony forming units. There were 300 CFU in the Postacute Care ward and the limit value of 100 CFU was in the ward of Internal medicine. The answers to research questions 'How to prevent reproduction of Legionella peumophylis in the water distribution system of the hospital in Cesky Krumlov?' and 'How to ensure a sufficient amount of quality hot water in the medical facility?' are included at the end of the stated recommendations. A risk factor causing the fast reproduction of Legionella is the old water distribution system in most of the buildings and low water temperature of water leaving the boiler, which is 55°C. All mentioned results and evaluations are included in this thesis as well as attached pictures, which show the environment and situation within the Health Care Institutions.
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Short and long term re-distribution of potentially toxic elements fractions in solid environmental samples
Jeřábková, Julie ; Drábek, Ondřej (advisor)
The fractionation of potentially toxic elements (PTE) in environmental and anthropogenic solid samples has a crucial influence on their leaching, mobility and bioavailability, or conversely, their immobilization. Redistribution of PTE in different fractions is affected by various soil properties, such as soil reaction, redox conditions, and soil organic matter composition and its content. Fractionation of PTE in soils and other environmental materials is therefore dynamic, as it is controlled by external conditions. Certain changes of soil conditions caused by, for example, climatic events (floods, soil washing, etc.) and human activities (eg. liming) may lead to significant changes in the distribution of fractions of PTE in soils and anthropogenic materials.
The aim of this study is to assess the impact of changes of conditions on the short- and long-term diferences in fractionation of selected PTE (As, Cd, Cr, Cu, Pb, Zn) in soils and other solid samples mainly of anthropogenic origin (e.g., smelter slag) in the environment.
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Spatial distribution and mobility of critically endangered Rock Grayling in the area of Orlik Reservoir
Váňová, Anežka ; Kadlec, Tomáš (advisor) ; Petr, Petr (referee)
The critically endangered grayling (Hipparchia hermione, syn.: alcyone) is one of the rapidly declining diurnal butterfly species which occupies only few remaining localities in the Czech Republic. Currently, its remaining local populations can be found in the central Povltavi area where they inhabit mostly sparse light oak forests with low cover of the herb layer. As a diploma thesis, the study was conducted during the season 2015. The populations of H. alcyone were researched around the Orlik water reservoir. The occurrence was confirmed at six localities out of which two had been unknown until then. Within four dense populations have been using the capture-recapture method evaluated the mobility and dispersal abilities of the species. The populations differed in their dispersal abilities. Various average long distances across localities and sexes were detected. The average long distances varied (males 142to300 m, females 78to261 m) across all locations. The flight probability were ascertained with two methods: the inverse power function (IPF) and the negative exponential function (NEF). The NEF method fitted better the flight probability at all localities. The interchanges of individuals between localities were noted only in a case of two closest populations. These one-way interchanges (three males and two females) were always directed from dense to smaller population. The adults of H. alcyone were typical by very low dispersions between separate populations, probably due to lower densities of populations and innapropriate structure of migration paths. Three overflights of males and two overflights of females to the neighbouring location were recorded. With respect to the size of local population and the structure of migration routes, the individuals expand with difficulties. In order to maintain and support habitats of new H. alcyone biotopes, the more open canopies and creation of a larger number of small clearings in the neighbourhood of the H. alcyone localities is necessary.
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Effect of climatic and environmental variables on changes in numbers and migratory behaviour of wintering and migrating waterbirds.
Adam, Matyáš ; Musil, Petr (advisor) ; Bejček, Vladimír (referee)
Waterbirds with their specific habitat and food requirements varying during their annual cycle (Riffell et al. 2003; Taft and Haig 2006) are able to indicate the wetland diversity and quality due to their rapid responses on changes in environment (Delany 1999; Fernández et al. 2005; Amat and Green 2010). Remarkable land cover changes and climate warming led to significant shifts in distribution and abundance of many waterbird species across Europe in recent decades (Delany et al. 2006; Fox et al. 2010; Lehikoinen et al. 2013; Pavón-Jordán et al. 2015). To understand the dynamic of migratory birds in space and time and to assess effects of global conditions as well as local conditions of individual sites during their annual cycle there is need of international monitoring and research. Since the start of International Waterbird Census in 1967 both increasing and decreasing trends have been recorded in nearly fifty percent of waterbird species in Western Palearctic (Delany et al. 2006, Wetlands International 2016) and they consequently have affected trends in particular countries, including the Czech Republic. Wetland sites in the Czech Republic are generally situated on the edge of wintering range of most waterbird species (Gilissen et al. 2002), however the prevailing increase in abundance of waterbird species has been recorded here in recent decades (Musil et al. 2011). Though, the considerable growth of winter temperatures has not been noticed in the Czech Republic (Klein Tank et al. 2002; Musilová et al. 2009; Dušek et al. 2013), and the accessibility of the wetland sites, due to their freezing, varies year to year. Hence, we can assume that waterbirds have likely began using the alternative habitats with available food resources, i.e. cold-weather refuges, probably regardless of their conservation status (Musilová et al. 2015). Special protection areas were implemented to Czech legislation in 2004 to protect migratory birds (Birds Directive 2009/147/EC). So far there has not been tested the effectivity and impact of legislative protection on wintering waterbird species. Moreover, some previous studies indicated that SPA network do not match the species distribution pattern (López-López et al. 2007; Briggs et al. 2012; Albuquerque et al. 2013), so this issue urgently calls for scientific research.
The second part of the thesis focused on Greylag Geese, whose abundance has rapidly grown across the Europe in recent decades (Madsen et al. 1999; Fox et al. 2010), and that have become ideal model species to observe their responses to habitats and climate changes as well as their reactions to human disturbance (Fox and Madsen 1997; Ramo et al. 2015). This requires appropriate knowledge of geese distribution, abundance and their behaviour. Since 1930s, when the geese started to be ringed in the Czech Republic, the ringing intensity have markedly varied and have been reflected in numbers of recoveries. In last ten years the intensity have increased (Podhrazský 2010). However, complex of the historical data until 2002 (Cepák et al. 2008) and recent data have not been analysed so far. In the light of recent shifts in wintering ranges and migration phenology of many goose populations these analyses require increased attention. Furthermore, the satellite monitoring of geese is coming to detect more detailed information about behaviour of individuals.
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Temporal variability in spatial distribution of carabid beetles in agricultural landscapes
Seidl, Miroslav ; Knapp, Michal (advisor) ; Harabiš, Filip (referee)
The aim of this thesis is to work out a brief literary research focused on spatial distribution of carabid beetles (Coleoptera, Carabidae) around arable field-woodland boundaries throughout the season. Substantial part of this thesis consistsof thefield experiment aiming to explore given issue in the model area near Sedlčany. Carabid beetles were collected employing pitfall traps along four transects perpendicular to arable field-woodlot boundaries. Beetles were sampled during five sampling periods, but only four complete (undamaged) temporal samples series were used for final statistical analyses:1) early spring, 2) late spring, 3) summer and 4) late autumn.Three species groups were identified according to their habitat specialization:1) open habitat specialists, 2) habitat generalists and 3) forest specialists; and these groups were analysed seperately.
Total species diversity was highest in area of ecotone between arable field and woodlot.The edge between habitats was preferred by habitat generalist species and open habitat specialist species also spilled over here. Distribution of relative species richness and relative activity density was not stable in time. Spatial distribution of forest species was relatively less variable. Open habitat species aggregated within habitat boundaries instead of field interiors in early spring, probably as a result of overwinteringbehaviour. Generalists were also aggregated in the edge between habitats in autumn period and during early spring occurred relatively more in the centre of woodlot than in other periods. Species composition of carabid beetles assemblages depended partly on season and also on position of transect. There was also a significant interaction between spatial and temporal variability in species composition of carabid assemblages. Woodlot assemblages seem to be less variable in time.
The results of this thesis contribute to extension of knowledges on distribution of carabid beetles in agroecosystems, where many carabids act aspredators of various pests. The biggest changes in spatiotemporal distribution of carabid beetles in agricultural landscape could be linked with preference of adults to overwinter out of arable land.
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The effect of ecotones on the overwintering of Winter damselflies (Odonata: Lestidae)
Dolejšová, Lucie ; Harabiš, Filip (advisor) ; Michal, Michal (referee)
Sympecma fusca is a species of winter damselflies with unique life history. The uniqueness of life history is coupled with overwintering in adult life stage in terrestrial environment, which is associated with high mortality rate. Such risk can be reduced by preference for specific habitats. Since terrestrial environment is frequently affected by anthropogenic disturbances, winter damselflies must respond to interventions into their habitat. This thesis focuses mainly on anthropogenic interventions into the habitat of winter damselflies and the impact of such disturbances on the distribution of individuals of species Sympecma fusca. Capture-Mark-Recapture Method was chosen for modelling of population dynamics in selected transects. Data collection took place during the pre-reproductive period within two years. Year-on-year comparison showed a decrease in abundance as well as changes in distribution of individuals in the studied transects. Individuals responded to habitat disturbances by searching for alternative micro-habitats, preferring places unaffected by anthropogenic disturbances. The acquired data indicate that winter damselflies are able to respond actively to environmental changes, nevertheless number of suitable habitats decreased significantly in the given site. This thesis is only a pilot study. Therefore, other reference sites are suggested for further study of anthropogenic influence on the life history of winter damselflies.
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