Application for Encrypted Communication

Cílem této bakalářské práce je vytvořit aplikaci pro operační systém Android, která umožňuje komunikaci přes šifrované OpenVPN spojení. Aplikace podporuje textovou komunikaci, hlasovou komunikaci, přenos videa a sdílení souborů mezi uživateli. První polovinu práce tvoří teorie týkající se využitých technologií, mezi které patří OS Android, OpenVPN, SIP protokol pro hlasovou a video komunikaci, XMPP protokol pro textovou komunikaci a Owncloud pro sdílení souborů. Druhá polovina práce se zabývá samotnou implementací aplikace. Jsou zde popsány API a knihovny, které byly při práci využity, struktura výsledné aplikace a její fungování včetně ukázek.The objective of this thesis is to develop an application for Android operating system that allows to communicate via encrypted OpenVPN connection. Application supports text messaging, voice communication, video transfer and sharing files between users. The first part of this thesis consists of theoretical description of used technologies including Android OS, OpenVPN, SIP protocol for voice and video communication, XMPP protocol for text messagging and Owncloud for file sharing. The second part deals with the implementation of the application itself. It describes the used API and libraries, structure of the final application and it's functioning including pictures.440 - Katedra telekomunikační technikyvýborn

On-Line Monitoring of Expiration of DNSSEC Signatures

V bakalářské práci je popsáno vytvoření programu, který kontroluje podpisy záznamů DNS (Domain Name System) a upozorňuje na jejich neplatnost nebo blížící se vypršení platnosti aby bylo možné včas zabránit vypršení platnosti. V práci je popsána technologie DNSSEC (Domain Name System Security), nové záznamy DNS pro DNSSEC a detaily podepisování záznamů DNS. Dále je zde popsán návrh programu, možnosti nastavení programu, způsoby čtení dat a způsoby výstupu upozornění. Práce vzniká z důvodu potřeby rychlé kontroly podpisů a upozornění na blížící se konec platnosti podpisů, protože žádný podobný program neexistuje.In the bachelor thesis we have described computer software (programme) which is supposed to check the signatures of DNS (Domain Name System) records (resource records) and warn in due time about the expiry date or the approaching expiry date of the signatures in order to prevent from expiring. In the paper we have specified the DNSSEC (Domain Name System Security) technology, new resource records for the DNSSEC and details of signing the resource records. Moreover, we have introduced the programme itself, the possibilities of setting the programme, the ways of data reading and warning output. Since no such programme exists, and because there is a need to check the signatures quickly and warn about their expiry date, we have decided for this work.

Measuring of adjusting accuracy and positional errors compensation

katedra: KVS; přílohy: 2xCD; rozsah: 68 s. (69444 znaků)This dissertation deals with the adjusting issues at the Computer Numerical Control (CNC) machine tool prototype. Further it follows up possibilities of positional errors compensation using a control system or changes in a machine construction itself. After measuring and evaluating results, the compensative file has been worked out. The measuring has been repeated after inputting compensative data into the control software. Due to compensation, particular cumulative errors range between ?40?m. The total precision of adjusting for the axis X is 42 ÷ -73 ?m.Diplomová práce se zabývá problematikou polohování na prototypu obráběcího CNC stroje. Také se zabývá možností kompenzace polohových chyb pomocí řídícího softwaru, popřípadě pomocí změn v samotné konstrukci stroje. Po naměření a vyhodnocení výsledků byl zpracován kompenzační soubor a po zadání kompenzačních dat do řídícího softwaru byla měření opakována. Jednotlivé součtové chyby se díky kompenzaci pohybují v rozmezí 40um a celková přesnost polohování pro osu X je 42 až -73 um

Replacing Natural Gas by Biogas — Determining the Bacterial Contamination of Biogas by PCR

A promising way of using biogas is to upgrade it to natural gas, which is referred to as Substitute Natural Gas (SNG) or biomethane. Biomethane, or biogas, is produced by biological processes of harnessing the ability of microorganisms to degrade organic material to methane. Some of the microorganisms are aerosolized from the digester into the biogas; afterwards a bio-film is formed that attaches to the surfaces of the distribution pipes, and can find it was to the place where the end use of biogas takes place. This paper deals with the detection of microbial species in biogas, their influenceon corrosion and the potential risk that diseases can be spread via biogas using molecular techniques. Using molecular methods, we found that raw biogas contains about 8 million microorganisms per m3, which is most likely the result of microbial transmission from the anaerobic digestion process. Some bacterial species may contribute to the corrosion of pipelines and equipment; others are opportunistic pathogens that can cause toxic reactions. However, most bacterial species, more than 40 % in biogas, are still unknown, as is their influence on the digestion process and on human health. Further studies are needed to better understand the behavior of microorganisms in anaerobic digestion and to preventmicrobial-influenced corrosion and microbial dissemination

Active optical fibers doped with ceramic nanocrystals

Erbium-doped active optical fiber was successfully prepared by incorporation of ceramic nanocrystals inside a core of optical fiber. Modified chemical vapor deposition was combined with solution-doping approach to preparing preform. Instead of inorganic salts erbium-doped yttrium-aluminium garnet nanocrystals were used in the solution-doping process. Prepared preform was drawn into single-mode optical fiber with a numerical aperture 0.167. Optical and luminescence properties of the fiber were analyzed. Lasing ability of prepared fiber was proofed in a fiber-ring set-up. Optimal laser properties were achieved for a fiber length of 20~m. The slope efficiency of the fiber-laser was about 15%. Presented method can be simply extended to the deposition of other ceramic nanomaterials

The effect of a high-grain diet on the rumen microbiome of goats with a special focus on anaerobic fungi

This work investigated the changes of the rumen microbiome of goats switched from a forage to a concentrate diet with special attention to anaerobic fungi (AF). Female goats were fed an alfalfa hay (AH) diet (0% grain; n = 4) for 20 days and were then abruptly shifted to a high-grain (HG) diet (40% corn grain, 60% AH; n = 4) and treated for another 10 days. Rumen content samples were collected from the cannulated animals at the end of each diet period (day 20 and 30). The microbiome structure was studied using high-throughput sequencing for bacteria, archaea (16S rRNA gene) and fungi (ITS2), accompanied by qPCR for each group. To further elucidate unclassified AF, clone library analyses were performed on the ITS1 spacer region. Rumen pH was significantly lower in HG diet fed goats, but did not induce subacute ruminal acidosis. HG diet altered prokaryotic communities, with a significant increase of Bacteroidetes and a decrease of Firmicutes. On the genus level Prevotella 1 was significantly boosted. Methanobrevibacter and Methanosphaera were the most abundant archaea regardless of the diet and HG induced a significant augmentation of unclassified Thermoplasmatales. For anaerobic fungi, HG triggered a considerable rise in Feramyces observed with both ITS markers, while a decline of Tahromyces was detected by ITS2 and decrease of Joblinomyces by ITS1 only. The uncultured BlackRhino group revealed by ITS1 and further elucidated in one sample by LSU analysis, formed a considerable part of the AF community of goats fed both diets. Results strongly indicate that the rumen ecosystem still acts as a source for novel microorganisms and unexplored microbial interactions and that initial rumen microbiota of the host animal considerably influences the reaction pattern upon diet change.Fil: Fliegerova, Katerina O.. Czech Academy of Sciences; República ChecaFil: Podmirseg, Sabine M.. Universidad de Innsbruck; AustriaFil: Vinzelj, Julia. Universidad de Innsbruck; AustriaFil: Grilli, Diego Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Cs.médicas. Departamento de Patología. Area de Microbiología; ArgentinaFil: Kvasnová, Simona. Czech Academy of Sciences; República ChecaFil: Schierová, Dagmar. Czech Academy of Sciences; República ChecaFil: Sechovcová, Hana. Czech Academy of Sciences; República ChecaFil: Mrázek, Jakub. Czech Academy of Sciences; República ChecaFil: Siddi, Giuliana. Università degli Studi di Sassari; ItaliaFil: Arenas, Graciela Nora. Universidad Nacional de Cuyo. Facultad de Cs.médicas. Departamento de Patología. Area de Microbiología; ArgentinaFil: Moniello, Giuseppe. Università degli Studi di Sassari; Itali

Anaerobic fungal communities differ along the horse digestive tract

Anaerobic fungi are potent fibre degrading microbes in the equine hindgut, yet our understanding of their diversity and community structure is limited to date. In this preliminary work, using a clone library approach we studied the diversity of anaerobic fungi along six segments of the horse hindgut: caecum, right ventral colon (RVC), left ventral colon (LVC), left dorsal colon (LDC), right dorsal colon (RDC) and rectum. Of the 647 ITS1 clones, 61.7 % were assigned to genus level groups that are so far without any cultured representatives, and 38.0 % were assigned to the cultivated genera Neocallimastix (35.1 %), Orpinomyces (2.3 %), and Anaeromyces (0.6 %). AL1 dominated the group of uncultured anaerobic fungi, particularly in the RVC (88 %) and LDC (97 %). Sequences from the LSU clone library analysis of the LDC, however, split into two distinct phylogenetic clusters with low sequence identity to Caecomyces sp. (94–96 %) and Liebetanzomyces sp. (92 %) respectively. Sequences belonging to cultured Neocallimastix spp. dominated in LVC (81 %) and rectum (75.5 %). Quantification of anaerobic fungi showed significantly higher concentrations in RVC and RDC compared to other segments, which influenced the interpretation of the changes in anaerobic fungal diversity along the horse hindgut. These preliminary findings require further investigation.</p

Identificación de Xilanasas GH10 en las cepas 2 y Mz5 de Pseudobutyrivibrio xylanivorans

El rumen contiene una población bacteriana encargada de la degradación del xilano, el principal componente de la hemicelulosa presente en la pared celular vegetal de los forrajes que consumen las cabras. Las bacterias del rumen, principalmente los géneros Butyrivibrio y Pseudobutyrivibrio, sintetizan una gama de enzimas xilanolíticas para la digestión eficaz de los componentes de la pared celular. Los genes que codifican para xilanasas pertenecientes a la familia glicosil hidrolasa 11 (GH11) y la actividad xilanasa asociada han sido identificados en la cepa tipo (Mz5) de P. xylanivorans. Por el contrario, poco se sabe acerca de la diversidad y distribución de los genes xilanasa GH10 en otras cepas de Pseudobutyrivibrio. // El objetivo del presente estudio fue identificar genes xilanasa GH10 en P. ruminis 153, P. xylanivorans 2 y Mz5. Además, se evaluó la degradación y utilización de xilano por las cepas aisladas del rumen de cabras Criollas

La producción de xilanasas por pseudobutyrivibrio xylanivorans confirma el potencial fibrolítico de este futuro probiótico

Recientemente, nuestro equipo logró aislar una bacteria de la especie Pseudobutyrivibrio xylanivorans (cepa 2) a partir del contenido ruminal de cabras Criollas. En esta cepa, se identificaron los genes que codifican para xilanasas involucradas en la degradación de la fibra vegetal. La caracterización de las enzimas fibrolíticas producidas por P. xylanivorans 2, mediante enzimogramas y la determinación de su actividad enzimática, confirmarían el potencial fibrolítico de esta cepa para ser utilizada como probiótico