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Face masks and respirators as protection against viruses and bacteria
Varga, Michal ; Mišík, Ondrej (referee) ; Lízal, František (advisor)
Pandemic caused by virus SARS-CoV-2 brought high attention to face masks and raised some questions about their filtration efficiency and performance affecting parameters such as high humidity, long term usage, fit factor, or possible decontamination methods for usage prolonging. In this thesis, mechanisms of SARS-CoV-2 transmission and structure and materials of face masks are firstly discussed. Then mechanisms of particle deposition on filter fibers are described. Subsequently standards of surgical masks, cloth masks and respirators are described and compared, with detail on carbon dioxide concentration under respirator. Nanoparticles and their possible effects on enhancing face mask parameters are briefly characterized. Then filtration efficiency and affecting parameters are evaluated. And finally possible decontamination methods for face masks reusability are summarized.
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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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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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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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Technological challenges in the fabrication of MoS.sub.2./sub./diamond heterostructures
Varga, Marián ; Sojková, M. ; Hrdá, J. ; Hutar, P. ; Parsa Saeb, S. ; Vanko, G. ; Pribusova Slusna, L. ; Ondič, Lukáš ; Fait, Jan ; Kromka, Alexander ; Hulman, M.
Nowadays, 2D materials are one of the most studied classes of materials. In addition to the most famous graphene, progress has been achieved in studying and using fundamental properties of transition metal dichalcogenides (TMD). Complementary, diamond as a representative of 3D materials has gained a reputation as an extremely versatile material due to its extraordinary combination of physical/chemical/electrical/optical properties. Besides these particular forms of 2D and 3D materials, their heterostructures have become very attractive due to new phenomena and functions (bandgap engineering, enhanced charge transport, optical interaction, etc.). However, individual technological procedures are still minimally investigated and described. Here, we will demonstrate a proof-of-concept for the preparation of MoS2/diamond heterostructures, where two different strategies were employed: a) growth of MoS2 layers on diamond films, and b) growth of diamond films on Si/MoS2 substrates.
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Experimental modelling of transport of inhaled fibrous particles in lungs
Varga, Michal ; Bělka, Miloslav (referee) ; Lízal, František (advisor)
Inhaled fibrous particles may either cause different potential diseases in our respiratory system or be used positively as drug carriers targeting specific parts of the respiratory system. To better understand their behaviour in both cases, either to assess their health risk or positive effects, precise knowledge of their movement behaviour in airways is needed. Since currently there isn’t much data describing the movement of fibrous particles in airways available, the goal of this thesis was to record their movement in the model of human trachea at the first bifurcation using a high-speed camera and breathing generator simulating real cyclic breathing patterns. Collected data were then processed and evaluated using five statistical tests. In the first three tests, the orientation of fibres to streamlines, possible flips from one orientation to another during their movement and the statistical significance of these events, were evaluated. In the fourth and fifth tests the length of fibre particles was evaluated.
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Tetrahedrization as an alternative to volume data
Varga, Martin ; Kolingerová, Ivana (advisor) ; Kohout, Josef (referee)
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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Face masks and respirators as protection against viruses and bacteria
Varga, Michal ; Mišík, Ondrej (referee) ; Lízal, František (advisor)
Pandemic caused by virus SARS-CoV-2 brought high attention to face masks and raised some questions about their filtration efficiency and performance affecting parameters such as high humidity, long term usage, fit factor, or possible decontamination methods for usage prolonging. In this thesis, mechanisms of SARS-CoV-2 transmission and structure and materials of face masks are firstly discussed. Then mechanisms of particle deposition on filter fibers are described. Subsequently standards of surgical masks, cloth masks and respirators are described and compared, with detail on carbon dioxide concentration under respirator. Nanoparticles and their possible effects on enhancing face mask parameters are briefly characterized. Then filtration efficiency and affecting parameters are evaluated. And finally possible decontamination methods for face masks reusability are summarized.
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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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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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