Design methods for computer networks

Bakalářská práce se zabývá problematikou vhodného návrhu počítačové sítě pro středně velkou infrastrukturu, jejím zabezpečením a následnou realizací směrovače s firewallem. Tento hraniční prvek bude schopný plnit základní úkony řízení síťového provozu mezi vnitřní a vnější sítí. V této práci je stručně provedena analýza modelu OSI a podrobněji jsme se zaměřili na model TCP/IP. Dále naše práce obsahuje popis a nastiňuje význam nejčastěji používaných prvků v daném typu sítě a jejich přínos pro zabezpečení. Následuje popis tří nejběžněji používaných topologií v daném typu infrastruktury. Na základě zjištěných informací je vybrána a analyzována nejvhodnější topologie a to především z bezpečnostního hlediska. Výsledkem toeretické části práce je návrh modelu sítě. V praktické části jsou některé nabyté poznatky otestovány a implementovány v reálném nasazení. Pro realizaci a otestování byla použita technologie virtualizace, pomocí které jsme nakonfigurovali router s firewallem, představující hraniční prvek, který odděluje vnitřní síť od vnějšího prostředí Internetu.Bacherol‘s thesis deals with a topic of a suitable computer network design for a mid-sized infrastructure, its security and router and firewall realization. This boundary element is able to manage basic processes of network controlling between inner and outer network. There is a brief analysis of OSI model but we focused our attention on TCP/IP model more closely. Our project includes description and outlines an importance of the most common elements of the particular network type and their contribution to the security. Description of the three most frequent topologies of the infrastructure type follows. On the basis of the found information, we have chosen and analysed the most suitable topology from the security point of view. The result of the theoretical part is a network model proposal. In the practical part, some our findings are tested and implemented in a real setting. We used a technology of virtualization for the final realization and testing. Thanks to the virtualization used for realization and testing, we could configure the router and the firewall, which are boundary elements that separate the inner network from the Internet.

Návrh efektívneho spôsobu merania rozmerov na princípe inerciálneho meracieho systému

The work presents automated methods of dimensions measurement, extending the known horizont of used approach to measuring by the draft of a new unused method. a method described in the paper is based on the principle of self-localization of inertial sensors that are able to describe the actual value of angular velocity and acceleration in the direction of each coordinate axis. Prerequisite accuracy of these measurements is a clear definition of zero position in space and taking into account a wide range of ambient effects. The method should allows to measure dimensions of objects of complex shape with high accuracy even in places where usage of conventional methods is not always possible. The contribution also describes principles of inertial navigation systems and MEMS technology, which significantly reduces the cost of mentioned advanced technologies.Práca približuje problematiku automatizovaných metód merania rozmerov, pričom rozširuje doteraz známy obzor používaných prístupov K meraniam O návrh novej, doteraz nepoužívanej, metódy. V práci popisovaný spôsob merania rozmerov vychádza Z princípu vlastnej lokalizácie inerciálnych senzorov, schopných popisovať aktuálne hodnoty uhlových rýchlostí a zrýchlení V smere jednotlivých súradnicových osí priestoru. Nutným predpokladom presnosti týchto meraní je jasná definícia nulovej polohy systému V priestore a zohľadnenie širšieho spektra vplyvov okolia. Metóda by mohla umožniť meranie rozmerov tvarovo zložitých objektov S vysokou presnosťou, a to dokonca aj na miestach, kde by to pri použití konvenčných metód meraní nemuselo byť vždy možné. Príspevok taktiež informačne popisuje princípy funkcie inerciálnych navigačných systémov a technológie MEMS, ktorá značne znižuje náklady na použitie týchto pokrokových technológií

Dyson-Schwinger Equations: Density, Temperature and Continuum Strong QCD

Continuum strong QCD is the application of models and continuum quantum field theory to the study of phenomena in hadronic physics, which includes; e.g., the spectrum of QCD bound states and their interactions; and the transition to, and properties of, a quark gluon plasma. We provide a contemporary perspective, couched primarily in terms of the Dyson-Schwinger equations but also making comparisons with other approaches and models. Our discourse provides a practitioners' guide to features of the Dyson-Schwinger equations [such as confinement and dynamical chiral symmetry breaking] and canvasses phenomenological applications to light meson and baryon properties in cold, sparse QCD. These provide the foundation for an extension to hot, dense QCD, which is probed via the introduction of the intensive thermodynamic variables: chemical potential and temperature. We describe order parameters whose evolution signals deconfinement and chiral symmetry restoration, and chronicle their use in demarcating the quark gluon plasma phase boundary and characterising the plasma's properties. Hadron traits change in an equilibrated plasma. We exemplify this and discuss putative signals of the effects. Finally, since plasma formation is not an equilibrium process, we discuss recent developments in kinetic theory and its application to describing the evolution from a relativistic heavy ion collision to an equilibrated quark gluon plasma.Comment: 103 Pages, LaTeX, epsfig. To appear in Progress in Particle and Nuclear Physics, Vol. 4

The Open IMS Core and the IP Multimedia Subsystem

This thesis describes architecture of IMS and shows possibilities of IMS platform testing. Theoretical part describes layer model of the IMS as a whole and then describes it’s individual layers. Next chapters analyse key entities of the IMS, interconnection between reference points and features of protocols used in the IMS. Practical part deals with the introduction of Open IMS Core, which was chosen for the IMS technology testing. Settings necessary to carry out testing and interconnection between PBX Asterisk are shown in next chapters. After introduction of IMS desktop clients is carried out an instant messaging communication within the IMS network. The communication is captured and analysed by Wireshark application. Afterwards there is described how SIP protocol sends messages within the IMS. After a brief introduction to the PBX Asterisk, there are discussed assumptions for the interconnection between Asterisk and IMS. There are also described necessary settings needed for implementation and communication testing itself. The first test is an audio session carried out between the desktop IMS client and IP phone registered to the PBX Asterisk. Communication is captured for the analysis of preparation, conduction and termination of the session. After the successful realization of the audio call, video session has been made. The session was analysed in detail, including statistics of control signals and transmitted packets. There are two laboratory excercises in attachement of this thesis, which will help students to understand the IMS technology and communication options within the IMS networ

Investigation of snake robot locomotion possibilities in a pipe

This paper analyzed the locomotion of a snake robot in narrow spaces such as a pipe or channel. We developed a unique experimental snake robot with one revolute and one linear joint on each module, with the ability to perform planar motion. The designed locomotion pattern was simulated in MATLAB R2015b and subsequently verified by the experimental snake robot. The locomotion of the developed snake robot was also experimentally analyzed on dry and viscous surfaces. The paper further describes the investigation of locomotion stability by three symmetrical curves used to anchor static modules between the walls of the pipe. The stability was experimentally analyzed by digital image correlation using a Q-450 Dantec Dynamics high-speed correlation system. The paper presents some input symmetrical elements of locomotion and describes their influence on the results of locomotion. The results of simulations and experiments show possibilities of snake robot locomotion in a pipe.Web of Science126art. no. 93

Salivary Thiobarbituric Acid Reacting Substances and Malondialdehyde – Their Relationship to Reported Smoking and to Parodontal Status Described by the Papillary bleeding index

Background. Thiobarbituric reacting substances (TBARS) are markers of lipoperoxidation. The best-known specific TBARS is malondialdehyde (MDA). Results from our previous studies have shown that TBARS can be measured in saliva and are increased in patients with gingivitis. Whether MDA is the main TBARS in saliva from patients with altered parodontal status is unknown. Aim. To observe the relationship between the parodontal status and TBARS, MDA and the number of epithelial cells in saliva. Subjects & Methods. In Study I saliva and plasma samples of 15 patients (8F, 7M) suffering from inflammatory periodontal diseases were gathered and TBARS levels were measured in these samples. In Study II saliva samples from 217 consecutive stomatologic patients were collected and analysed for TBARS spectrofluorometrically, MDA by high-performance liquid chromatography and epithelial cell count by light microscopy. Papillary bleeding index (PBI) was determined in standard stomatologic examination. Results. In Study I results from our previous studies showing no correlation between salivary and plasma TBARS levels were confirmed. This indicates that the local salivary level of TBARS is unlikely to be directly affected by systemic oxidative stress. In Study II higher PBI was associated independently (adjusted for age and sex) tightly with higher TBARS (p < 0.001) and with lower number of epithelial cells in saliva (p < 0.05). Smokers had higher salivary MDA levels (p < 0.003) and lower number of epithelial cells in saliva (p < 0.01). Conclusion. Salivary TBARS are a simple parameter that partially reflects the parodontal status with a potential usefulness in the clinical stomatology. We show herein that salivary MDA is dependent on age and smoking, but there is no correlation between MDA and PBI. Further studies should uncover the main salivary TBARS compound in patients with altered parodontal status and trace the origin of these salivary lipoperoxidation markers