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Extensions to Probabilistic Linear Discriminant Analysis for Speaker Recognition
Plchot, Oldřich ; Fousek, Petr (referee) ; McCree,, Alan (referee) ; Burget, Lukáš (advisor)
Tato práce se zabývá pravděpodobnostními modely pro automatické rozpoznávání řečníka. Podrobně analyzuje zejména pravděpodobnostní lineární diskriminační analýzu (PLDA), která modeluje nízkodimenzionální reprezentace promluv ve formě \acronym{i--vektorů}. Práce navrhuje dvě rozšíření v současnosti požívaného PLDA modelu. Nově navržený PLDA model s plným posteriorním rozložením modeluje neurčitost při generování i--vektorů. Práce také navrhuje nový diskriminativní přístup k trénování systému pro verifikaci řečníka, který je založený na PLDA. Pokud srovnáváme původní PLDA s modelem rozšířeným o modelování neurčitosti i--vektorů, výsledky dosažené s rozšířeným modelem dosahují až 20% relativního zlepšení při testech s krátkými nahrávkami. Pro delší testovací segmenty (více než jedna minuta) je zisk v přesnosti menší, nicméně přesnost nového modelu není nikdy menší než přesnost výchozího systému. Trénovací data jsou ale obvykle dostupná ve formě dostatečně dlouhých segmentů, proto v těchto případech použití nového modelu neposkytuje žádné výhody při trénování. Při trénování může být použit původní PLDA model a jeho rozšířená verze může být využita pro získání skóre v případě, kdy se bude provádět testování na krátkých segmentech řeči. Diskriminativní model je založen na klasifikaci dvojic i--vektorů do dvou tříd představujících oprávněný a neoprávněný soud (target a non-target trial). Funkcionální forma pro získání skóre pro každý pár je odvozena z PLDA a trénování je založeno na logistické regresi, která minimalizuje vzájemnou entropii mezi správným označením všech soudů a pravděpodobnostním označením soudů, které navrhuje systém. Výsledky dosažené s diskriminativně trénovaným klasifikátorem jsou podobné výsledkům generativního PLDA, ale diskriminativní systém prokazuje schopnost produkovat lépe kalibrované skóre. Tato schopnost vede k lepší skutečné přesnosti na neviděné evaluační sadě, což je důležitá vlastnost pro reálné použití.
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Business Plan of Testing committee of Veteran Car Club Strakonice
Horáková, Bára ; Novák, Michal (advisor) ; Dvořák, Jiří (referee)
This thesis solves the emergence of a new club testing committee of the historic vehicles in Strakonice. The aim of the thesis was to determinate under what real conditions can be the new commission, functional, have enough costumers, successful and profitable. The thesis calculated three possible variants of financial analysis. For a better understanding of the market was used questionnaire survey of the market. Thesis also contains Porter´s Five Forces Analysis and SWOT analysis. Finally, were summarized all the findings, especially what competitive advantage should the commission use to succeed in the market, and in what a number of tests, and financial situation it makes sense to work and when it would terminate its activities.
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Optimization of network flow monitoring
Žádník, Martin ; Lhotka,, Ladislav (referee) ; Matoušek, Radomil (referee) ; Sekanina, Lukáš (advisor)
The thesis deals with optimization of network flow monitoring. Flow-based network traffic processing, that is, processing packets based on some state information associated to the flows which the packets belong to, is a key enabler for a variety of network services and applications. The number of simultaneous flows increases with the growing number of new services and applications. It has become a challenge to keep a state per each flow in a network device processing high speed traffic. A flow table, a structure with flow states, must be stored in a memory hierarchy. The memory closest to the processing is known as a flow cache. Flow cache management plays an important role in terms of its effective utilization, which affects the performance of the whole system. This thesis focuses on an automated design of cache replacement policy optimized to a deployment on particular networks. A genetic algorithm is proposed to automate this process. The genetic algorithm generates and evaluates evolved replacement policies by a simulation on obtained traffic traces. The proposed algorithm is evaluated by designing replacement policies for two variations of the cache management problem. The first variation is an evolution of the replacement policy with an overall low number of state evictions from the flow cache. The second variation represents an evolution of the replacement policy with a low number of evictions belonging to large flows only. Optimized replacement policies for both variations are found while experimenting with various encoding of the replacement policy and genetic operators. The newly evolved replacement policies achieve better results than other tested policies. The evolved replacement policy lowers the overall amount of evictions by ten percent in comparison with the best compared policy. The evolved replacement policy focusing on large flows lowers the amount of their evictions two times. Moreover, no eviction occurs for most of the large flows (over 90%). The evolved replacement policy offers better resilience against flooding the flow cache with large amount of short flows which are typical side effects of scanning or distributed denial of service activities. An extension of the replacement policy is also proposed. The extension complements the replacement policy with an additional information extracted from packet headers. The results show further decrease in the number of evictions when the extension is used.
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The Pump with a Diffuser with Stochastic Blades (Runner and Diffuser)
Dobšáková, Lenka ; Melichar, Jan (referee) ; Veselý, Jindřich (referee) ; Haluza, Miloslav (advisor)
This doctoral thesis studies the non-uniform blade cascade for centrifugal pumps. Influence of non-uniform blade cascade is investigated on the impeller and diffuser. A non-uniform blading impeller of pumps in this doctoral thesis was examined in terms of influence on efficiency characteristic. The idea of using non-uniform blading is to obtain a flat efficiency characteristic. Then the centrifugal pump could be used on larger scale of power with achieving a sufficiently high efficiency. The work is based on experimental measurements and numerical simulations of non-uniform hydraulic pump components. Non-uniform impeller and the diffuser were newly designed for this research. A new measuring track of small submersible pumps was needed to design and build for measurements. Different pump combinations with conventional hydraulics on one working point and hydraulics with non-uniform were measured. All measurements were evaluated and characteristics of efficiency, head and power were obtained for each measured combination. Some of pump combinations (which were measured in experiment) were numerically simulated by program Ansys Fluent. Data needed to evaluate the characteristic of efficiency and specific energy were collected from each numerical simulation. A theoretical consideration concerns the influence of non-uniform blade cascade applied on diffuser. The suggestion how to decrease hydraulic losses in canals was done. The theoretical consideration how to make a flat efficiency characteristic was made.
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Effect of a graduate of field of study Special Education - tutorship in practice of providers of social care
SALABOVÁ, Jana
Theoretical part of the thesis is divided into 4 main chapters. First one deals with the helping professions generally, their definitions and definition of the Special education - Tutorship branch of study per se.It also briefly touches the subject of readiness of the future graduates to deal effectivelly with the challenges of a career in the field of social services. Chapter number two is called Special education and it defines the subject of special education itself, it's purpose and inner structure. Third chapter focuses on social services. It brings up it's definition and types and forms of social services.It also contains the examples of the institutions which fall into this category and it's providers. Chapter number four, which happens to be the last one in the theoretical part of the thesis, covers the role and purpose of graduates of the special education - tutorship studies. It brings up the definition of a social worker, necessary prerequisites as well as beneficial personality traits and feautures. In a subchapter of chapter four is a short description of a pedagogue tutor. Definition who he actually is, who are proper candidates for this position, what are desired personality traits we look for in tutors and the actual content and purpose of their work in institutions providing social services. The end of chapter four is dedicated to a position of a social worker. His activities, the position and definition of a personal assistant and again personality traits needed for a successful career in this field. The objective of the practical part of the thesis is to describe working of Special education - tutorship studies graduates in practice. Particularly their experiences "from the field", how do they evaluate the level of skill of fresh graduates during their first encounters with the reality, how satisfied are they with their choice of a career so far and what was their motivation to pursue such career. Practical part of the thesis includes qualitative research. To meet the above objectives, data collection technique had been chosen using a structured interview with the respondents, who were graduates of Special education tutorship studies. You can tell by the results of this thesis that graduates in the field of social services apply mostly to lower positions as a social service workers, even though they are qualified to perform as a social workers. The age of clients with whom the respondents work ranges from childhood to senior. The motivation that led those questioned respondents to the decision to choose the area of social services varies. Some reported that they were influenced by the actual practical experience during their studies at the university, when both the work itself and their enthusiasm for the target group played role. Others expressed they had previous experience working with people with disabilities or they just wanted to acquire new experiences. Also, involvement of a family member and their previous education was a motivation. Job satisfaction is evident from observed data, and it also contributes to work done accurately and responsibly. Personal benefits for the respondents according to findings are usually their usefulness at work, new experiences they are getting and last but not least advances of their clients. As the biggest advantage the respondents usually mention variability of their work, target group and the clients in itself and the fact, that their work is highly satisfying and they basically work in a very pleasant team of individuals. On the other hand, not exactly satisfying financial reward and challenging working hours are mentioned as disadvantages. Special education - tutorship studies - the branch they've studied, is by the majority of respondents considered to be beneficial for them and they especially highlight practical impact of practice they completed during their studies and which included visits to various relevant institutions.
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Specifics of nursing care in patients after transapical aortic valve implantation.
VOTRUBOVÁ, Nataliya
Transcatheter aortic valve implantation (TAVI) is a new and an attractive method in cardiology and as well as in cardiac surgery. It is constantly evolving method which has been developed as an alternative to standard open surgery, especially in patients with severe symptomatic aortic stenosis with unacceptably high perioperative risk or patients who are not suitable for conventional open heart surgery because of age and comorbidities.A teamwork is very importantfor this new method and approach. The choice for TAVI is discussed by the institutional multidisciplinary heart team, typically consisting of interventional cardiologists, imaging-specialists, cardiac surgeons and anaesthesiologists. The first implant in a human being was performed by Cribierin 2002. In Czech Republic this method was first used in 2008. Transcatheter aortic valve implantation (TAVI) was accepted as a minimally invasive alternative to open surgery. This method does not require the use of cardiopulmonary bypass, and cardiac arrest. Other several benefits includinglower risks of bleeding and stroke events, better wound healing, less pain, as well as more rapid early recovery due to preservation of continuity of the sternumthat result in shorter durations of stay in the hospital, earlier rehabilitation and faster returns to normal life. In the presented work was used a combination of qualitative-quantitative methods of investigation. The data was obtained by using the quantitative research. The main technique was using the questionnaires designed for nurses working at the Department of Cardiac Surgery, Hospital Czech Budejovice, a. s. These results were backed up by the implementation of qualitative research, which investigated the patients and physicians view on monitored issues. Questioning method using a semi structured interview technique was used for qualitative research. The results of the survey were processed using descriptive statistics charts in LibreOffice Calc and using diagrams created in LibreOffice Writer. Qualitative results of the research were transcribed from audio recordings and coded, and the base code was created nine categories of interviews with clients/patients and three categories of interviews with doctors. The aim of this work was to explore the specific problem of nursing care about the clients / patients after transapical aortic valve implantation. On the base of our obtained data it is evident, that the client/patient after TAVI may be positioned sideways, the use of surgical drains are less frequently, so the care about the surgical wounds is simpler, patients report less pain in the surgical wound and postoperative rehabilitation and recovery is shorter. H1 - The nurses take care about the clients/patients after transapical aortic valve implantation in the same way as about the clients/patients after open aortic valve replacement, without realizing the differences between the patients treated with different approaches, was not confirmed. The nurses'sees/reported major differences in invasiveness and extent of providing care, rehabilitation, convalescent, in the duration of the hospitalization and better cosmetic effect. The results of the research can serve as a basis for creating the standards of nursing care or educational material for clients/patients. It is also possible to present the results of this work at a specialized seminar for non medical healthcare workers and results can also increase the quality of nursing care about the clients/patients after transapical aortic valve implantation.
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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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Nové postupy biomonitoringu cizorodých látek ve vodním prostředí
ČERVENÝ, Daniel
Within the presented work, several approaches of biomonitoring were studied. A well-established method for human health risk assessment was applied to evaluate the quality of fish from open waters in the Czech Republic. As this work is targeted on sport fishermen, who frequently consume their own catches, besides the publication in scientific journal, a brochure with results of this study was distributed via the Czech Fishing Union. Health risks for consumers related to the consumption of wild fish were found strongly species and locality dependent. As there is no risks related with the consumption of carp (Cyprinus carpio) at all investigated sites, frequent consumption of predatory fish should be avoided at some fishing grounds. The use of passive samplers has become more and more attractive in the last two decades. As these devices are able to mimic the biological uptake of chemicals, their potential for replacing fish as bioindicators in routine biomonitoring programmes is evident. In our study, the comparison between analysis of fish tissues and POCIS extracts from selected sampling sites confirms this idea about interchangeability of these indicators in the case of PFASs as target pollutants. Moreover, no metabolic transformation of contaminants present in water take place in passive samplers contrary to living organisms, thus these reflect the actual contamination at the locality more precisely. The use of passive samplers completely fulfils the internationally accepted principles of Replacement, Reduction, Refinement (the three R´s). Another promising approach using YOY fish as bioindicators was evaluated within the present study. Multispecies samples of YOY fish homogenate was found as a better indicator for wide range of pollutants than muscle tissue of adult fish within one species from the same locality. As all inner organs and tissues are presented in analysed samples, more target pollutants in higher concentrations are detected compared to the muscle of adults. Besides the higher sensitivity in pollutants detection and quantification, practical and economic benefits are of concern in the case of the YOY fish approach. The YOY fish approach also particularly fulfil the three R´s strategy, as sampling of this age group of fish has a smaller impact on the environment than the sampling of adults. In case of mercury, that was found as a limiting contaminant for the consumption of fish from open waters in the Czech Republic, a nonlethal method of finclips sampling can be used for the monitoring of this compound in aquatic environments. Besides the monitoring, our optimised method for the estimation of muscle tissue concentrations could be used for human health risk assessment as well. The difference between real muscle concentrations and concentrations estimated using our method differs less than 10% in most of the investigated localities. Benthic organisms are an important part of the food web in aquatic environments, but insufficient information about its contamination is available. In another study included in this thesis, first evidence about bioaccumulation of certain pharmaceuticals in benthic organisms was described. Although, pharmaceuticals are generally considered to be not accumulative in organisms, our study proved that certain pharmaceuticals have bioaccumulation potential. From this finding, it is evident that not only the concentrations of pharmaceutical dissolved in water but also the diet represents an important exposure pathway of contamination by these compounds for organisms (fish) inhabiting aquatic environments.
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The use of (nano)oxides for metal and metalloid stabilization in contaminated soils
Michálková, Zuzana ; Komárek, Michael (advisor) ; Luke, Luke (referee)
The main objective of the thesis was to evaluate the potential of selected Mn and Fe (nano)oxides for the stabilization of metals and metalloids in contaminated soils. The research was focused basically on three materials - commercial nanomaghemite (Fe III), nanomagnetite (Fe II,III) and a synthetic amorphous Mn oxide (AMO). The main aim of the work was to provide a complex view on the chosen stabilizing amendments regarding not just their direct influence on contaminants mobility and stabilization mechanisms, but also their stability and alterations in soil conditions together with influence on soil microorganisms and higher plants. Firstly, adsorption properties of the tested materials towards Cd, Cu, Pb and As were investigated. In this context, the most effective material showed to be the AMO reaching one to two orders of magnitude higher adsorption capacities than Fe III and Fe II,III under given experimental conditions. Interestingly, the rate of As(V) adsorption onto AMO was increasing with increasing pH as a result of high pHzpc of the AMO (8.1) and significant dissolution of this phase at lower pH values. As a next step, the influence of (nano)oxides on metal(loid)s mobility and other physico-chemical soil characteristics after application to contaminated soil was examined. Again, the AMO proved to be the most efficient in reducing mobile pools of Cd, Cu, Pb, Zn and As. On the other hand, Fe III and Fe II,III addition had generally less significant effects on contaminants mobility. AMO application further resulted in an increase of soil pH connected with AMO dissolution and unwanted decomposition of soil organic matter. When (nano)oxides alterations in soil conditions were observed, MnCO3 coatings were identified on AMO surface while no significant changes were recorded for Fe III and Fe II,III. As the MnCO3 formation was connected with increased AMO stability, AMO particles synthetically covered with MnCO3 coating (denoted as SM AMO) were prepared. Although the SM-AMO had a lower mass loss in soil than pure AMO, the stabilizing efficiency was almost the same for both materials. The differences in surface composition of both materials were decreasing with time as MnCO3 naturally precipitated on the AMO surface in soils while the SM AMO coating was gradually dissolving. When investigating the effect on soil microbiota, AMO efficiently promoted soil microbial activity while no significant changes were observed in the case of Fe III and Fe II,III. The AMO was also able to reduce the uptake of Cd, Pb and Zn by sunflower (Helianthus annuus L.), eliminate Zn phytotoxicity symptoms and increase biomass yield. On the other hand, toxic levels of Mn released from the AMO in an acidic soil were found in sunflower tissues. AMO application is thus recommended for contaminated neutral or slightly alkaline pH with a higher cation exchange capacity in order to avoid unwanted release of Mn. Finally, various types of AMO-biochar composite sorbents were recently prepared and field experiment focused on stabilization of Cd, Pb, Zn and As using studied materials is currently under preparation. The combined results from the thesis highlight the importance of a complex experimental approach dealing with all parts of the contaminated soil environment in order to obtain complete information about the efficiency and usefulness of any newly developed stabilizing amendment.
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Competitive advantage
Gregora, Jakub ; Tichá, Ivana (advisor) ; Pavel, Pavel (referee)
This diploma thesis was based on the main theme of Competitive advantage. The theoretical part of this thesis is concerned with concepts of competition, competitiveness and competitive advantage. Next part is based on analysis of outside surroundings where are specified the main methods of analysing company surroundings. The names of the methods are PEST analysis, SWOT analysis and Porter five forces. In the last part of theoretical thesis are explained types of innovation and innovation process.
The conceptual part of the diploma thesis is related to company Snag s.r.o. and its evolution in two periods. The aim of these analysis where to name the main elements with the biggest impact. In the end of the first period was made a decision about new company strategy. According to the new company strategy there was effected innovation process that created new product for selling. This innovation has had crucial market to the competitive position of the company. The implementation of the new strategy has started new periond of growing the company.
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