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Povaha toku modelových suspenzí
Kulaviak, Lukáš ; Večeř, Marek ; Růžička, Marek ; Drahoš, Jiří ; Hladil, Jindřich
The main object of the present investigation is to test the settling abilities of mixtures of solid particles in liquids. The key quantity here is the magnitude of the viscosity, both of the carrying liquid (water-glycerol solutions) and the effective viscosity of the two-phase mixture. Few model systems were used (glass and polystyrene pellets), to study the settling process. The sedimentation were recorded by a video camera and the resulting deposit structure was photographed. Besides, also a real suspension was tested, of geological materials (calcite, quartz, mixed geological powder, etc.). Immersion rotary viscometer Brookfield with special spindles (RVT and V spindles) was used to measure the effective viscosity of the dispersion.
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Selected nanoparticles systems and their physical and chemical properties
Tyrpekl, Václav
of "rigorous" work Author: MSc. Václav Tyrpekl Supervisor: RNDr. Daniel Nižňanský, PhD. Katedra Anorganické Chemie Přírodovědecká Fakulta, Univerzita Karlova v Praze Name: Selected systems of nano-particles and their physico-chemical properties Presented work belongs to the topic of solid-state chemistry, which focuses mainly on the preparation and characterization of nano-particles and nano-composites. The introduction describes current knowledge of classical magnetism and magnetism of small particles. Next paragraphs describe the sol-gel technique, which uses alkoxides of transition elements for preparation of gels, xerogels and nano-composites. The introduction ends by the overview and explanation of experimental techniques that were employed for final sample characterization. The experimental work is divided in three thematic parts: i) Preparation and characterization of CoFe2O4/SiO2 composite in the form of spheres of few microns in diameter ; ii) Preparation and characterization of Fe3O4/SiO2 composite in the form of spheres with core- shell morphology with diameter of several tens of nanometers ; iii) Preparation and characterization of Fe2O3/TiO2 composite with photo-catalytic properties. In the first part, the SiO2 micro-spheres of average 11 micrometers in diameter, doped by...
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Artificial neural networks for clustering and rule extraction
Iša, Jiří
Title: Artificial neural networks for clustering and rule extraction Author: Jiří Iša Department: Department of Software Engineering Supervisor: RNDr. Iveta Mrázová, CSc. Supervisor's e-mail: mrazova@ksi.ms.mff.cuni.cz Keywords: fuzzy, rules, extraction, neural network Abstract: Rule extraction with neural networks has been a com- mon research topic over the last decades. This master thesis proposes a novel growing fuzzy inference neural network, based on the principle of growing neural structures. This allows the network to adjust iteratively its number of hidden neurons. For the purpose of this network an existing clustering algorithm is en- hanced to improve the sensitivity to the requested output. A novel fast weights adaptation, inspired by the fuzzy set theory, is also suggested. The characteristics of the proposed model and a new method of the selection of significant input features support the induction of a relatively small amount of simple fuzzy rules. The introduced techniques have been exper- imentally tested on real-world data describing the relationship between various types of housing in the Boston area and its price. The data was obtained from the "Boston housing" dataset.
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Application limits of sublingual drug administration. 1
Turnerová, Lenka ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
The theoretical part of thesis provides basic information about the sublingually administered drugs, describes the primary facts of the medicated membranes for oral systemic administration and about dextrans as the pharmaceutical substances. The experiment focuses on transmucosal in vitro evaluation of permeation of the dextrans of three different molecular weights from aqueous environment throughout sublingual membrane. The measurements of fluxes of caffeine as a marker at the opening period of permeation experiments were performed. An acceptor phase was always the phosphate buffer, pH 7.4. Determination of caffeine was performed by HPLC, the dextrans were determined spectrofluorimetrically. The average flux of caffeine is J = 1370 µg/cm2 .h-1 , SEM = 100,8 (n = 17). The proof of the transmembrane passage of all the mentioned fluorescent-labelled dextrans was given. Surprisingly, the lower permeation rates of dextran 4000 (J = 28,1 µg/cm2 .h-1 ; SEM = 21,4) comparing with dextran 20 000 (J = 42,0 µg/cm2 .h-1 ; SEM = 11,8) were found.
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Vektorová DIS cartridge pro Oracle
Nidrle, Václav ; Skopal, Tomáš (referee) ; Kopecký, Michal (advisor)
Oracle Text is an information retrieval system, which is included in Oracle database. It is built up on the basic Boolean model being further extended by features like assigning weights to individual tokens, calculating similarity of query and documents or fuzzy logic. The new database cartridge called Vector Text is implemented as the extension of Oracle Text, however it is based on the Vector space model. Thanks to this fact the possibilities of controlling the output amount and measuring the relevance of the returned documents are improved. For this purpose there is prepared a lot of functions for calculating token weight and similarity measure of query and document in Vector Text. The simple interface for their further extensions is also present there. The user interface of Vector Text cartridge kept the same principles used in the Oracle Text. Furthermore, the possibility of using special functionalities of Oracle Text being applicable in both models like thesaurus or stoplist have been preserved.
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Fyzickálně-chemický model homogezovaného procesu taveného skla
Němec, Lubomír ; Jebavá, M.
The contemporary approach to melting process improving leads to melting modeling either by complex models working under real conditions or by simplified partial models which are well adjustable and may be completed into more complex models according to actual need. The second way is more promising when trying to find non-traditional arrangements of the melting process or when solving partial melting or vitrification problems. The system of models involves models of glass melt behavior, particle behavior and particle or component distribution in the melt. The modular system of models allows to realize the tailored model. The examples of model completing and using are presented.
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The assessment of the presence of the intracranial hypertension by means of the compression Doppler-ultrasound in posthaemorhagic newborns' hydrocephalu
Rejtar, Pavel ; Eliáš, Pavel (advisor) ; Šprindrich, Jan (referee) ; Skotáková, Jarmila (referee)
Aim. In our study we focused on the ultrasound diagnostics of intracranial hypertension in neonates with diagnosis of posthemorrhagic hydrocephalus (PHH). We wanted to try and verify the method of "pressure provocation test". When performing this test, the great fonticulus is compressed by ultrasound probe and simultaneously systolic and diastolic velocities are being measured in the internal genu of the anterior cerebral artery with resisistive index calculation. Pressure on fonticulus during examination shows us the reserve capacity of liquor spaces and the response in cerebral arteries blood flow. The primary objective was to verify, if the basic and compressive resistive index correlates with the presence and eventually with the severity of intracranial hypertension. The secondary objective was to find relationship between the degree of intracranial hypertension and the diameter of cerebral ventricles, to asses the rapidity of PHH developement and to find out, in which period is PHH the most common. Method. In years 1999 - 2008, 52 children with diagnosis of posthemorrhagic hydrocephalus were examined in our department. The average birth weight in children with PHH was 1436 g (550 - 4090 g, median 1150 g). The average age was 29,6 weeks (24 - 41 weeks, median 28 weeks). Totally, 73 % of children...
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The Comparison of Websites of Selected Worldwide Cties
Novák, David ; Toman, Prokop (advisor) ; Pavlíček, Antonín (referee)
The main goal of this thesis is to create a methodology for comparison of web pages of worldwide cities and to apply it on the selected websites. Introductory theoretical part describes the history and the present of web pages and shows their categorization, technologies, key statistics and reasons of rising significance of city websites with emphasis on e-Government. The official web pages of London, New York and Sydney are compared. These are modern world-known cities comparable in population, used languages and the overall attractiveness. Methodology of comparison tries to be objective, universal and reusable. It evaluates the websites with a set of criteria divided into 4 domains: graphical design, usability, accessibility and information content. In the end the final ratings are determined as weighted averages of criteria and domains.
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Evidence of eneolithic textile production in Bohemia
Korteová, Judita ; Dobeš, Miroslav (advisor) ; Březinová, Helena (referee)
The aim of the thesis is to describe the technological as well as social connections of the textile production in Aeneolithic Bohemia, examined principally on archaeological evidence from Aeneolithic settlements, especially whirles, weights, awls and spools. Evaluated as for their number, shapes, dimensions, functions and archaeological context, the finds are being related to data coming from abroad, mainly from the pile-dwelling settlements in Switzerland, known as localities with preserved organic material. The thesis also includes a description of the various phases and techniques of the textile production, whose archaeological evidence is being compared with items found in Bohemia. The situation in Aeneolithic is being put in a broader context of the textile production in prehistoric and protohistoric times. Keywords awls, Bohemia, Aeneolithic, textile production, weights, whirls
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