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Observation of HF Cathode and ARC Root Inside Cutting Plasma Torch
Šonský, Jiří ; Gruber, Jan
Electric arc and a cathode of a cutting plasma torch was observed through fused silica window in a specially modified nozzle. Sample rate of used high-speed camera was up to 120 kHz, sufficient for detecting high-frequency fluctuations in arc plasma intensity, produced mainly by current ripple. Fluctuations were examined up to 60 kHz by Fast Fourier Transformation (FFT). Increased cathode material loss at start-up and shut-down phase of the plasma torch was observed. At start up phase, large number of small particles are ejected from the cathode. After electric current shuts down, large droplets of molten material are usually detected.
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Clustering and regression analysis of micro panel data
Sobíšek, Lukáš ; Pecáková, Iva (advisor) ; Komárek, Arnošt (referee) ; Brabec, Marek (referee)
The main purpose of panel studies is to analyze changes in values of studied variables over time. In micro panel research, a large number of elements are periodically observed within the relatively short time period of just a few years. Moreover, the number of repeated measurements is small. This dissertation deals with contemporary approaches to the regression and the clustering analysis of micro panel data. One of the approaches to the micro panel analysis is to use multivariate statistical models originally designed for crosssectional data and modify them in order to take into account the within-subject correlation. The thesis summarizes available tools for the regression analysis of micro panel data. The known and currently used linear mixed effects models for a normally distributed dependent variable are recapitulated. Besides that, new approaches for analysis of a response variable with other than normal distribution are presented. These approaches include the generalized marginal linear model, the generalized linear mixed effects model and the Bayesian modelling approach. In addition to describing the aforementioned models, the paper also includes a brief overview of their implementation in the R software. The difficulty with the regression models adjusted for micro panel data is the ambiguity of their parameters estimation. This thesis proposes a way to improve the estimations through the cluster analysis. For this reason, the thesis also contains a description of methods of the cluster analysis of micro panel data. Because supply of the methods is limited, the main goal of this paper is to devise its own two-step approach for clustering micro panel data. In the first step, the panel data are transformed into a static form using a set of proposed characteristics of dynamics. These characteristics represent different features of time course of the observed variables. In the second step, the elements are clustered by conventional spatial clustering techniques (agglomerative clustering and the C-means partitioning). The clustering is based on a dissimilarity matrix of the values of clustering variables calculated in the first step. Another goal of this paper is to find out whether the suggested procedure leads to an improvement in quality of the regression models for this type of data. By means of a simulation study, the procedure drafted herein is compared to the procedure applied in the kml package of the R software, as well as to the clustering characteristics proposed by Urso (2004). The simulation study demonstrated better results of the proposed combination of clustering variables as compared to the other combinations currently used. A corresponding script written in the R-language represents another benefit of this paper. It is available on the attached CD and it can be used for analyses of readers own micro panel data.
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Internal equity principle in the context of company strategy
Kopecký, Martin ; Nový, Ivan (advisor) ; Háša, Stanislav (referee) ; Blažek, Ladislav (referee)
The thesis deals with the scientific problem of the link between the strategic management and the compensation system using the principle of internal equity. The work is based on two pillars, namely the qualitative research and own proposed solution. The first part of the thesis describes the qualitative research and the possibilities and the synergistic effects of linking business strategy and compensation system. The qualitative research is performed as a multi-case study and investigates the phenomenon in the practice of three companies from various markets (the Czech Republic, Slovakia and Bosnia and Hercegovina) and industries (finance, IT/Telco and FMCG). The research tries to find answers to the four research questions: How does business strategy influence compensation process? How can compensation support the realization of a business strategy? How can business strategy be linked with a compensation system within the principle of internal equity? How can compensation reinforce the strategic function of the human resources management? The research is based on the study of theoretical sources as well as on practical fieldwork. The qualitative research itself uses qualitative research methods for data collection, such as observations, questionnaires, and document analysis. The population questioned was top managers, line managers and representatives of HR department. In total, 142 interviews were performed by a single person. The collected data were analyzed and the triangulation was applied. The findings were summarized and generalized into a final report that brings answers to the research questions above. The research brings valuable findings used in the second, design part of the thesis. The own proposed solution consists of two main models. The first one is a simplified scheme of the compensation system and the second one is a model of strategic segmentation of jobs. The first model could be used successfully in the business practice as well as in education. The second model of the strategic job segmentation brings answer to the question of synergistic linking of business strategy and the compensation system within the principle of internal equity. The model brings valuable findings and a foundation for further theoretical research and its further development. The model also brings practical solution to the design of related policies and processes in the strategic management of human resources. By the design of both proposed models the main objectives of the thesis were achieved.
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IT requirements management of insurance company
Dvorský, Petr ; Bruckner, Tomáš (advisor) ; Jungmannová, Barbora (referee)
The first part of thesis deals with theoretical knowledge, thus defining the concepts of recommendations from the field of requirements management. The second part focuses on the identification, analysis and subsequend design solutions to problems arising from working with the requirements. Methods for identifying problems are carried out workshop, participant observation and interviews with employees from the IT sector of the insurance company. The outputs of this work are proposals for improving requirements management, some of them are successfully applied in Kooperativa. The first draft, which was applied to create a process library. Further, of four different types of prioritization was selected and applied method that is defined by ITIL. Other outputs are design of new user interface of requirements software and starting to design a Change Advisory Board, which is compared to ITIL enhanced with additional features. Further was established Business Consultant Department, which has task of efficiently collecting client requirements and the supporting documents were created for this department.
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CRM System Optimization
Fučík, Ivan ; Mildeová, Stanislava (advisor)
This thesis is focused on CRM solutions in small and medium-sized organizations with respect to the quality of their customer relationship. The main goal of this work is to design an optimal CRM solution in the environment of real organization. To achieve this goal it is necessary to understand the theoretical basis of several topics, such as organizations and their relationship with customers, CRM systems, their features and trends. On the basis of these theoretical topics it is possible to analyze current CRM solution in the organization. From the data obtained by the methods of observation and controlled interview it was possible to prepare a design for optimal CRM solution. This optimal solution comes also from user and organization requirements. The optimal CRM solution saves time and costs associated with current CRM solution and replaces existing and ineffective CRM tools.
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ELECTRON BEAM REMELTING OF PLASMA SPRAYED ALUMINA COATINGS
Matějíček, Jiří ; Veverka, J. ; Čížek, J. ; Kouřil, J.
Plasma sprayed alumina coatings find numerous applications in various fields, where they enhance the properties of the base material. Examples include thermal barriers, wear resistance, electrical insulation, and diffusion and corrosion barriers. A typical structure of plasma sprayed coatings, containing a multitude of voids and imperfectly bonded interfaces, gives them unique properties - particularly low thermal conductivity, high strain tolerance, etc. However, for certain applications such as permeation barriers or wear resistance, these voids may be detrimental.\nThis paper reports on the first experiments with remelting of plasma sprayed alumina coatings by electron beam technology, with the purpose of densifying the coatings and thereby eliminating the voids. Throughout the study, several parameters of the e-beam device were varied - beam current, traverse velocity and number of passes. The treated coatings were observed by light and electron microscopy and the thickness, structure and surface morphology of the remelted layer were determined and correlated with the process parameters. Based on the first series of experiments, the e-beam settings leading to dense and smooth remelted layer of sufficient thickness were obtained. In this layer, a change of phase composition and a marked increase in hardness were observed.\n
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Characterization of FRET sensor
Datinská, Vladimíra ; Klepárník, Karel ; Belšánová, B. ; Minárik, M. ; Foret, František
In this study, we present characterization of sensor based on Fӧrster resonance energy\ntransfer (FRET). The sensor is composed of ssDNA chain attached to a laboratory\nsynthesized quantum dot (QD). A complementary chain of a sample is labeled by a\nluminescent dye. When the dsDNA hybrid is formed, the energy from the QD (donor)\nis transferred to the dye (acceptor) and FRET is observed as a decrease of QD\nluminescence emission intensity and an increase of dye luminescence emission\nintensity.
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Miřenka Čechová
Janečková, Kateřina ; PETIŠKOVÁ, Ladislava (advisor) ; SOPROVÁ, Jana (referee)
Monographic work focuses on artistic creation Miřenka Čechová, one of the
the leading personalities of our contemporary stagecraft. Her personal and
artistic development started when she began studying dance and continued to
mimic and physical theater. Material presents her contribution to
contemporary Czech scene physical theater and refers to her international
success. Work observes her role like co-founder of physical theaters Theatro
Pantomissimo and Spitfire Company and to presents the work of these
physical theaters and reveals the working and teaching methods in the
preparation of copyright performances.
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Study of physiology and searching of proteomic tools useful in suppression and detection of Varroa destructor
Holenková, Martina ; Erban, Tomáš (advisor) ; Titěra, Dalibor (referee)
This work is focused on the study of physiology and proteome of the the mite Varroa destructor and on comparison with the honeybee Apis mellifera. Varroa is currently a major problem for beekeeping, because infects most of the colonies. The control of the mite can not be done without residues both in the hive and for example in the honey or other resources used by the man. Another problem can also be the simultaneously discussed issue of the connection with the Colony Collapse Disorder. The internal anatomy of V. destructor was studied by using paraffin histology. On histological sections stained using hematoxylin and PAS was possible to observe the mite digestive system, but also egg, ovaries or brain. The primary aim of this study was to identify the proteins of mite V. destructor and bee A. mellifera as a host of this parasite. For the electrophoretic separation was used two- dimensional gel electrophoresis, where the second dimension was carried out using 12% and 15% SDS-PAGE. The most abundant spots were selected for analysis using MALDI TOF/TOF mass spectrometry. The most abundant protein identified in samples of V. destructor was hexamerin, arginine kinase or hemelipoglycoprotein precursor. Hexamerins were also identified as the major proteins in the pupae samples. On the contrary the main...
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Arctic tundra dendrochronology
Lehejček, Jiří ; Svoboda, Miroslav (advisor) ; Monika, Monika (referee)
Historically unprecedented environmental change in the Arctic ecosystems is often given into the context of its past and possible future development. In the region where instrumental meteorological observations are scarce archives need to be investigated in order to address this issues. The comprehensive synthesis one of the archives: long-live circumpolar evergreen Juniperus communis L. shrub is presented here. 20 individuals from southwest Greenland were investigated at the cell anatomy level to understand the ecology of the species and unhide its potential for environmental and climate reconstructions. The findings are as follows:
i) Stop of exponential cross-sectional conduit-lumen widening with increasing age is in contrast with conduit-lumen nature of trees. This indicates that shrubs do not need to saturate their water and nutrient demands via traits of classical hydraulic conductivity law but rather developed different mechanisms. Extreme weather conditions result in prostrate growth form. However, different weather factors probably influence shrub growth differently: While snow and wind act mechanically (a), temperature influences the form of growth physiologically (b). a) So long as the young shrub stem has high resilience to bend back to an upright position after snow melt and so long as it can withstand the wind during the vegetation season it most likely grows upright and the conduit-lumens widen. b) Temperature, resp. freeze-thaw events are responsible for the shrubs preference of safety (finite size of conduit-lumens) over hydraulic efficiency, thus not allowing for more primary growth. All of these (and other) factors are apparently working together and the transition of vertical to more horizontal growth is gradual. As a consequence, the conduit-lumen sizes may not have to be further increased (due to ecophysiological restrictions possibly also must not) because water is no longer transported against gravity.
ii) Observed age/growth trend has to be taken into consideration for further employment of the wood anatomical parameter in paleoenvironmental studies. That is, shrub cell parameters can only be used for this purposes if correctly detrended. This allows for more accurate as well as longer reconstructions because youth trend was often neglected in reconstructions based on shrub annual-rings.
iii) The south-western Greenland Ice-Sheet (GrIS) melt rates reconstruction is presented for the whole 20th century. This part of GrIS is considered as the most active. According to the presented reconstruction current GrIS melt rates are not uncommon for the last century being comparable to first decades of 20th century. This finding is particularly important contribution to the debate on Atlantic meridional overturning circulation (AMOC). Too high fresh water inputs into the Northern Atlantic from GrIS melting may slow down or even stop the AMOC which would result in more continental climate in Europe. Presented results indicate that this threshold lies higher than observed current melt rates of GrIS.
Fascinating Juniperus comunnis species has shown to be able to address many ecological as well as environmental open questions and due to its longevity and abundant distribution has a great potential to become an important player in the Arctic research.
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