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Comparison of the Effect of Fingerprint Image Compression Algorithms on the Quality of Matching Algorithms
Varga, Marek ; Kanich, Ondřej (referee) ; Drahanský, Martin (advisor)
Táto práca si kladie za cieľ zhodnotiť vplyv rôznych možností kompresie a techník spracovania obrazu pre rôzne typy snímok odtlačkov prstov. Kvalita kompresných metód sa otestuje pomocou rôznych techník porovnávania odtlačkov prstov na meranie podobnosti medzi spracovaným a pôvodným obrázkom odtlačku prsta. Práca hodnotila výkonnosť kompresií JPEG, PNG a WSQ, ako aj porovnávače založené na markantoch, krížovej korelácií a PSNR. Techniky spracovania odtlačkov prstov zahŕňali normalizáciu obrazu, binarizáciu, zmenu bitovej hĺbky, odstránenie šumu a zmenu veľkosti obrazu. Výsledkom bolo, že kompresia PNG zaznamenala najlepšie priemerné skóre pre všetky typy odtlačkov prstov podľa všetkých testovaných porovnávačov. Okrem toho kompresia JPEG zaznamenala najlepšie priemerné kompresné časy, zatiaľ čo kompresia WSQ priniesla najmenšie komprimované veľkosti súborov. Techniky spracovania snímok odtlačkov prstov nezlepšili skóre zhody, iba ich zhoršili.
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Correlated microscopy of electronic and material properties of graphene grown on diamond thin films
Rezek, Bohuslav ; Čermák, Jan ; Varga, Marián ; Tulic, S. ; Skákalová, V. ; Waitz, T. ; Kromka, Alexander
In this work we compare growth of graphene on diamond thin films that enable large area processing. We use films with different crystal size and surface roughness to obtain deeper insight into formation and properties of GoD. The diamond films are coated by a nm thin sputtered Ni layer and heated to 900°C in a forming gas atmosphere (H2/Ar) to initiate catalytic thermal CVD process. The samples are cleaned from residual Ni after the growth process. We employ scanning electron microscopy, Raman micro-spectroscopy and Kelvin probe force microscopy to correlate material, structural, and electronic properties of graphene on diamond. We show how grain size and grain boundaries influence graphene growth and material and electronic properties. For instance we show that the grain boundaries (with non-diamond carbon phases) in diamond films have an important role. They influence the electronic properties and they are beneficial for forming graphene on diamond higher quality.
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Study of electrical and dielectric properties of conducting polymers
Varga, Martin ; Prokeš, Jan (advisor) ; Petzelt, Jan (referee) ; Pfleger, Jiří (referee)
Title: Study of electrical and dielectric properties of conducting polymers Author: Mgr. Martin Varga Department: Department of Macromolecular Physics Supervisor: RNDr. Jan Prokeš, CSc., Department of Macromolecular Physics Abstract: Charge transport in polyaniline (PANI) and polypyrrole (PPy) was studied in respect to various oxidants, dopants, morphology, and other modifica- tions in their synthesis. The mechanism of transport was discussed in the frame- work of combination of several models characteristic for disordered solids due to inherent heterogeneous structure of conducting polymers. Effect of drying on conductivity was studied and the long-time limit was explained with the diffusion- based model for bulk materials. For PPy nanotubes stability in strong alkaline media and aging were studied by AC and DC techniques. While conductivity of naturally aged samples after two years remained in the same order of magni- tude, after exposure to alkaline media or accelerated aging at high temperatures, conductivity decreased several orders of magnitude. Degraded material exhibited strong disorder and the transport model was completely changed. Despite severe treatment electrical properties were still comparable to other as-prepared mate- rials. Finally, an application example as ammonia sensor, the response of...
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Allogenous venous graft in reconstructive vascular surgery - the use of immunosuppression in experiment.
Varga, Martin ; Oliverius, Martin (advisor) ; Vaněk, Ivan (referee) ; Staffa, Robert (referee)
(ENGLISH) Background: The investigation of the immunosuppression usage in cardiovascular surgery and interventional cardiology is, at present, concentrated on three main topics: 1) influence on intimal hyperplasia of coronary and peripheral vascular reconstructions 2) influence on rejection of allogeneic vascular grafts and 3) influence on intimal hyperplasia of coronary arteries after endovascular interventions. Modern immunosuppressive drug FK506 (Tacrolimus) could have a positive effect for these indications. In experimental study, FK506 inhibited rejection of arterial allografts and also inhibited intimal hyperplasia in percutaneous coronary interventions. Aims: The purpose of this study was to evaluate the effect of systemic tacrolimus treatment on the process of arterialisation of allogeneic and syngeneic venous grafts in a rat vein-to-artery implantation model. Material and Methods: Lewis (LEW) rats were used as recipients of syngeneic (Lewis) or allogeneic (Brown-Norway; BN) iliolumbar veins which were implanted into abdominal aorta. Recipients were divided into six groups. In groups A, E and F were animals after syngeneic (LEW to LEW) and in groups B, C and D were animals after allogeneic (BN to LEW) transplantations. Animals in the groups C and F had daily intramuscular injections of...
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Studium stejnosměrných a střídavých charakteristik polyanilinu v závislosti na technologii přípravy
Varga, Martin ; Prokeš, Jan (advisor) ; Valentová, Helena (referee)
Our aim in the present work is to provide and evaluate AC and DC characteristics of the polyaniline based materials. Different experiemtal techniques and devices have been used to achieve this goal. An introduction to the theoretical concepts of conductivity is given as well. The core of this thesis is an investigation of temperature and low pressure dependences, as well as the ageing effects for two systems (composites) in respect of the different preparation conditions such as dopants and their molar concentration, origin and the content of inorganic component and the way of polymerisation. An agreement with theoretical models is discussed.
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Tetrahedrization as an alternative to volume data
Varga, Martin ; Kohout, Josef (referee) ; Kolingerová, Ivana (advisor)
Main goal of the thesis was to research or propose a suitable method for substitution of volume data including volume data derived from motion pictures by irregular tetrahedron-based grids. The method should minimize the loss of information and the size of the data. The thesis proposes a method for finding a suitable tetrahedron grid that substitutes the volume data without assuming anything about its inner structure. The proposed method can be applied on both volume data and volume data from motion pictures. The method consists of two steps. First a basic grid is generated by a simple incremental algorithm and then it is improved by a process of simulated annealing. The thesis proposes an unbiased measure for measuring the loss of information and evaluates the suitability of the proposed method for both types of data based on experiments. The thesis includes an implementation of the proposed method which demonstrates its use. The thesis also includes sample volume data and motion picture volume data which were used to test the suitability of the method.
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Valuation of Plzeňský Prazdroj, a.s.
Varga, Matúš ; Brabenec, Tomáš (advisor) ; Poborský, František (referee)
This master thesis is concerned with the estimation of the market value of equity of Plzeňský Prazdroj, a.s. as at 30 September 2016. The market approach has been selected as the primary valuation approach with the largest impact on the value estimation; specifically the guideline public company method and the comparable transactions method are employed. The income approach based on the DCF Entity method verifies the value conclusion derived from the market approach. The going concern premise is supported by thorough analyses concerning the relevant market; market position of the valued company in relation to its competitors; and its financial health. The thesis concludes a clearly defined and justifiable range of value.
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3D Volume Rendering Data Visualization
Varga, Marek ; Herout, Adam (referee) ; Kršek, Přemysl (advisor)
This thesis deals with using theoretical knowledge of computer graphic and vector mathematics for volume data construction and vizualization. This work provides more methods volume data vizualization and optimization. Algorithms and mathematical principles are necessary for data obtaining, correct interpretation, filtration and error correction and vizualization. This work describes possibilities of method voxel splatting. Model which implements this method is a part of this work and it contains some techniques for drawing process which include skipping empty sections and effective addressing of properties of volume data. System also provides interactive rendering and volume data manipulation.
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Anti-Collision System Based on GPS
Varga, Marek ; Drahanský, Martin (referee) ; Orság, Filip (advisor)
Aircraft industry is constantly facing the need to increase security not only in the case of large machines, but also in the small aircraft. Many systems were established in order to inform the pilot of the impending hazard, where appropriate, about the location of the other aircraft. The main objective is to establish a facility which uses global position system for determining the position and imparts coordinates using wireless networks for subsequent determination of collision. The functions of satellites and GPS receivers, sending wireless data and collision calculation and synchronization of individual modules is described in detail.
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