Simple-Semi-Conditional Versions of Matrix Grammars with a Reduced Regulating Mechanism

This paper discusses some conditional versions of matrix grammars. It establishes several characterizations of the family of the recursively enumerable languages based on these grammars. In fact, making use of the Geffert Normal forms, the present paper demonstrates these characterizations based on matrix grammars with conditions of a limited length, a reduced number of nonterminals, and a reduced number and size of matrices

Location of node real position on the Internet

V této diplomové práci se zabývám problematikou určení pozice počítače v síti Internet. Potřeba určité lokalizace počítačů vznikla v posledních několika letech z důvodu vzniku překryvných sítí. Pro tuto činnost existuje mnoho algoritmů. Moje práce se zabývá metodou King, která odhaduje vzdálenost mezi komunikujícími stanicemi pomocí stávajícího systému pro překlad doménových jmen. Cílem této práce je ověřit přesnost metody King na stanicích v experimentální síti PlanetLab, která poskytuje přístup na více než 1000 stanic rozmístěných po celém světě.In this thesis I focus on finding the position of computers on the Internet. This need for locating computers originated in the last several years through the creation of overlay networks. For this activity there are many algorithms. This paper describes the King method that estimated the distance between communicating stations by using the domain name system. The aim of this work is to verify the accuracy of the King method in experimental PlanetLab network. This network provides access for more than 1000 stations worldwide.

De Facto States and Democracy: The Case of Abkhazia

De-facto states constitute an interesting and important anomaly in the international system of sovereign states. No matter how successful and efficient in the administration of their territories they are, they fail to achieve international recognition. In the past, their claims for independence were based primarily on the right to national self-determination, historical continuity and claim for a remedial right to secession, based on alleged human-rights violations. Since 2005, official representatives of several de facto states have repeatedly emphasised the importance of democracy promotion in their political entities. A possible explanation of this phenomenon dwells in the belief that those states which have demonstrated their economic viability and promote the organization of a democratic state should gain their sovereignty. This article demonstrates the so called "democracy-for-recognition strategy" in the case study of Abkhazia. On the basis of the field research in Abkhazia we identify factors that promote, as well as those that obstruct the democratisation process in the country.

Conditions of Democratization in De-facto States: Case Study of Abkhazia

De-facto states constitute an interesting anomaly in the international system of sovereign states. No matter how long their control of claimed territory has lasted or how effective their capacities to provide governmental services to its population are, they fail to achieve international recognition. A change in the legitimising strategy adopted by the leaders of de-facto states came with the recognition of Kosovo’s independence by most western powers. In the past, their claims to independence were based primarily on the right to national self-determination, historical continuity and claim to a remedial right to secession, based on alleged human-rights violations. Increasingly, though, these arguments have been supplemented by an emphasis on “democratisation-for-recognition-strategy”. According to this strategy, those states that proved their viability as democratic states should earn their sovereignty. The aim of this article is to demonstrate this strategy on an instrumental case study of Abkhazia. As a result of the study of secondary literature on the topic of de-facto states democratization, supported with field research in Abkhazia, we try to identify those factors which are promoting and on the other hand obstructing a democratization process in such a de-facto state

Hybrid Laser Technology for Composite Coating and Medical Applications

Nano-composite layers were synthesised by pulsed laser deposition (PLD) combined with magnetron sputtering, ion gun modification and RF discharges, and by dual pulsed laser ablation using simultaneously two KrF excimer lasers and two targets. Diamond-like carbon (DLC), Cr-containing diamond-like carbon (Cr-DLC), silver-doped hydroxyapatite (Ag-HA) and silver doped 316L steel and Ti6Al4V were prepared by hybrid laser technologies for potential coating of medical implants. Growing DLC films were modified during the laser deposition (10 J cm–2) by ion bombardment. Energy of argon ions was in the range between 50 eV and 210 eV. Content of sp2 "graphitic" and sp 3 "diamond" bonds, doping, structure, mechanical and biocompatible properties were tested. Deposition arrangements and experiences are presente

Mechanical properties of a biodegradable self-expandable polydioxanone monofilament stent: In vitro force relaxation and its clinical relevance

Biodegradable stents are promising treatments for many diseases, e.g., coronary artery disease, urethral diseases, tracheal diseases, and esophageal strictures. The mechanical properties of biodegradable stent materials play a key role in the safety and efficacy of treatment. In particular, insufficient creep resistance of the stent material could result in premature stent collapse or narrowing. Commercially available biodegradable self-expandable SX-ELLA stents made of polydioxanone monofilament were tested. A new, simple, and affordable method to measure the shear modulus of tiny viscoelastic wires is presented. The important mechanical parameters of the polydioxanone filament were obtained: the median Young's modulus was (E) over tilde = 958 (922, 974) MPa and the shear modulus was (G) over tilde= 357 (185, 387) MPa, resulting in a Poisson's ratio of nu = 0.34. The SX-ELLA stents exhibited significant force relaxation due to the stress relaxation of the polydioxanone monofilament, approximately 19% and 36% 10 min and 48 h after stent application, respectively. However, these results were expected, and the manufacturer and implanting clinician should be aware of the known behavior of these biodegradable materials. If possible, a biodegradable stent should be designed considering therapeutic force rather than initial force. Additionally, new and more advanced biodegradable shape-memory polymers should be considered for future study and use

Dobrodružství historické interpretace

Title in English: The Adventure of Historical Interpretation This collection of nineteen essays written by prominent historians demonstrates the diversity of academic approaches. Their work with historical sources, the foundation stone of research, is combined with ethical and aesthetic decision-making, which forms an indisputable part of their work. This is often surprising - both for the readers and themselves. It represents a great intellectual adventure. They cannot invent sources or set arbitrary rules, plots, and twists and turns, as a novelist might. However, they can write a scientific work which is the result of a creative approach

Quality of Services in Wireless Networks 802.11

Tato bakalářská práce podává ucelený přehled o bezdrátových sítích typu 802.11, známých pod označením Wi-Fi. Obsahuje tři hlavní části, z nichž první dvě jsou teoretické poznatky. V první části se práce týká problematiky zabezpečení těchto sítí a v druhé pak problematiky kolem zajištění kvality služeb, QoS. Třetí, praktická část, se zaměřuje na ověření správné funkce standardu 802.11e, který zajišťuje v sítích 802.11 podporu kvality služeb. Protože došlo v posledních letech k obrovskému zvýšení poptávky po multimediálních službách, je tato podpora v bezdrátových sítích nezbytná.This bachelor’s thesis reports an integrated view of wireless networks of standard 802.11, known as Wi-Fi. It contains three main parts, the first two of them are theoretical knowledge. The first part of work have to do with the security issue of WLAN, the second part refers to security issue of quality of services (QoS). The aim of the third, practical part is to verify the right functions of standard 802.11e, which ensures the support of quality of services in networks 802.11. Because of huge expansion of multimedia services demand, is this support in wireless networks necessary.