Optimizing an LTS-Simulation Algorithm

When comparing the fastest algorithm for computing the largest simulation preorder over Kripke structures with the one for labeled transition systems (LTS), there is a noticeable time and space complexity blow-up proportional to the size of the alphabet of an LTS. In this paper, we present optimizations that suppress this increase of complexity and may turn a large alphabet of an LTS to an advantage. Our experimental results show significant speed-ups and memory savings. Moreover, the optimized algorithm allows one to improve asymptotic complexity of procedures for computing simulations over tree automata using recently proposed algorithms based on computing simulation over certain special LTS derived from a tree automaton

Optimizing an LTS-Simulation Algorithm (Technical Report)

When comparing the fastest algorithm for computing the largest simulation preorder over Kripke structures with the one for labeled transition systems (LTS), there is a noticeable time and space complexity blow-up proportional to the size of the alphabet of an LTS. In this paper, we present optimizations that suppress this increase of complexity and may turn a large alphabet of an LTS to an advantage. Our experimental results show significant speed-ups and memory savings. Moreover, the optimized algorithm allows one to improve asymptotic complexity of procedures for computing simulations over tree automata using recently proposed algorithms based on computing simulation over certain special LTS derived from a tree automaton

Presidents of the Czech Republic - Medial Representations of Václav Havel and Václav Klaus

Jaroslav Šimáček - Abstrakt diplomové práce Diplomová práce "Prezidenti České republiky a jejich mediální obraz" analyzuje mediální obraz prezidentů ČR Václava Havla a Václava Klause v časopise Týden. Po vymezení role prezidenta v českém politickém systému a seznámení s konkrétními hlavami státu v životopisné části se autor zabývá rolí a funkcí médií v současném světě. Objasňuje přitom způsoby mediální komunikace a vytváření mediálních obrazů. Následně zkoumá nové technologické možnosti médií a postup při obsahové analýze médií, která je vybraná jako hlavní metoda. V metodologické části autor sestavuje hypotézy, týkající se mediálního obrazu prezidentů ČR, popisuje konkrétní metody práce a charakterizuje vybrané médium. Zvoleným výzkumným obdobím je druhé funkční období obou prezidentů. V praktické části se autor snaží stanovené hypotézy dokázat nebo vyvrátit. Výzkum probíhá především v internetovém archivu časopisu Týden, který obsahuje data od roku 1994 a je poměrně přehledný. Cílem práce je vytvoření mediálního obrazu Václava Havla a Václava Klause ve vybraném médiu. Klíčová slova: prezident, Česká republika, Václav Havel, Václav Klaus, média, mediální obraz, obsahová analýza, TýdenJaroslav Šimáček - Diploma Thesis Abstract The diploma thesis "Presidents of the Czech Republic - Medial representations of Václav Havel and Václav Klaus" analyses media images of presidents of Czech Republic Václav Havel and Václav Klaus in magazine Týden. After delimination president's role in czech political system and introducing to concrete heads of the state in the biographical part, author deals with media's role and function in contemporary world. At the same time he brings out medial communication manners and generation media images. Consequently he examines new technological possibilities in medial world plus procedure at media content analysis, which is chosen as main method. In methodology part author links hypotheses, concerning with media images of czech presidents, also describes concrete working methods and characterizes choice of medium. Select experimental period is the second presidential term of both presidents. In practical part author tries to prove or disprove given hypotheses. The research proceeds first of all in the internet archive of magazine Týden, that contains data since 1994 and is relatively well - aranged. The aim of this diploma thesis is creation of media images of Václav Havel and Václav Klaus in chosen medium. Key words: president, Czech Republic, Václav Havel, Václav...Katedra občanské výchovy a filosofieFaculty of EducationPedagogická fakult

Military brownfields in the Czech Republic and the potential for their revitalisation, focused on their residential function

One of the basic transformation processes of the period since 1989 has been that of demilitarisation. Among other things, one of its consequences is the emergence of abandoned military buildings and areas – so-called military brownfields. These kinds of brownfields have a large number of specific features to which their subsequent revitalisation must necessarily be adapted. Since a large number of these areas are situated within municipalities or are directly adjacent to them, it is essential for their revitalisation to be approached with great sensitivity. This contribution deals with chosen examples of Czech revitalised post-military areas with a special view to their residential function, which is presently their dominant functional use

A Restriction of Sentetial Forms of of Scattered Context Grammars

Tato práce zavádí pojem zobecněných gramatik s rozptýleným kontextem, které se od tradičních liší tím, že levé strany pravidel mohou obecně obsahovat řetězec neterminálních symbolů namísto jediného neterminálu. Dále jsou studovány dva typy omezení při větné derivaci v těchto gramatikách. Nechť k je konstanta. První omezení požaduje, aby přepsání všech symbolů nastalo mezi prvními k symboly v prvním souvislém bloku neterminálů ve větné formě v každém derivačním kroku. Druhé omezení definuje derivaci pouze nad větnými formami, které obsahují nejvýše k výskytů neterminálů. Jako hlavní výsledek práce demonstruje, že oba typy omezení snižují vyjadřovací sílu na úroveň bezkontextových gramatik.This work introduces and discusses generalized scattered context grammars that are based upon sequences of productions whose left-hand sides are formed by nonterminal strings, not just single nonterminals. It places two restrictions on the derivations in these grammars. More specifically, let k be a constant. The first restriction requires that rewriting all symbols occurs within the first k symbols of the first continuous block of nonterminals in the sentential form during every derivation step. The other restriction defines the derivations over sentential forms containing no more than k occurrences of nonterminals. As its main result, the thesis demonstrates that both restrictions decrease the generative power of these grammars to the power of context-free grammars.

Hydrotreating of waste plastic pyrolysis oil with increased chlorine and nitrogen content

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Upgrading of wheat/barley and miscanthus bio-oil over a sulphided catalyst

In recent years, the production of biofuels from non-food crops wastes and harvesting residues plays an important role in the improvement of the global environment and in the replacement of declining oil reserves1. Hydrogenation of lignocellulosic bio-oil is attracting much attention as a suitable way to produce petroleum-refinery compatible feedstock. Primarily, hydrogenation of bio-oil is carried out under severe reaction conditions in two-stage fixed-bed reactors, filled with a noble metal catalyst in the first zone and with a sulphided catalyst in the second zone2. This setup allows producing low-oxygen upgraded bio-oil, however, it is economically unviable and operationally complicated. Here, we present the results from 80 h long hydrogenation experiments of miscanthus and wheat/barley straw bio‑oils obtained by one-stage condensation (2-5 °C) or fractional condensation (75 °C) ablative fast pyrolysis (AFP). Bio-oils from fractional condensation, in contrast to those from one-stage condensation, were stable and did not separate into an aqueous and organic phase. In that case, operation with these bio-oils was much easier than with bio-oils from one-stage condensation. Upgrading of bio-oils was performed in a one-stage fixed bed reactor filled with a laboratory-made NiMo/Al2O3 catalyst under constant reaction conditions (340 °C, 4 MPa and WHSV 1 h-1), which we identified in our previous research as suitable reaction conditions. Hydrogenated products separated spontaneously into an aqueous phase, formed predominantly by water, and an organic phase. In this work, we used various analytical methods for the determination of physicochemical properties (density, viscosity, elemental analysis etc.) and chemical composition (CAN, Carbonyls by Faix, GC-MS for volatile compounds and hydrocarbons) of the organic products. In addition, we used FTIR in combination with the principle component analysis (PCA) to take a snapshot of the catalyst health and product quality. In all hydrogenated products, we have observed a drop in the quality with the increasing time-on-stream, which may be caused by catalyst deactivation and coke formation, as it shown in Figure 2. Nevertheless, the coke formation and reactor clogging, during the hydrogenation of miscanthus bio-oil, was so high that we were forced to stop the experiment after 36 hours. The observed decrease in Micro Conradson Carbon residues and CAN of the products from wheat/barley straw bio-oil indicated a significant improvement of the product stability. The laboratory-made NiMo/Al2O3 catalyst was suitable for the upgrading of straw bio-oil, from one-stage and from fractional condensation AFP, and can be further developed for the upgrading for other feedstocks. Please click Additional Files below to see the full abstract

Prostorne slike i promjene u njihovom grafičkom prikazu kod učenika osnovne škole

Depiction of a geographical area through drawings is an individual ability, significantly variable over time. The essential development of such ability can primarily be observed during the period starting from what is termed younger school age to the period of pubescence. This study presents the results of a research focused on monitoring the development of the ability of students aged between 6 and 15 to reproduce their mental image of a well-known geographical area in the form of a drawing (cognitive or mental map). The research was carried out by the method of analyzing the drawings of comparative mental maps produced by primary and lower secondary school students. The data obtained from the research were then statistically evaluated on the basis of selected criteria in order to find identical or different stereotypes in the drawings. Research results point to the existence of significant differences in the ability to graphically illustrate a wellknown geographical space, reflecting, in particular, the age (or degree of experience gained) and, to a lesser extent, the gender. Such findings are important from the pedagogical point of view, because the creation of graphic representation of a certain area belongs to the basic geographical competencies of students.Prikaz geografskoga prostora putem crteža individualna je sposobnost, značajno promjenjiva kroz vrijeme. Temeljni razvoj takve sposobnosti primarno se može promatrati u razdoblju od tzv. mlađe školske dobi do razdoblja puberteta. Ovim radom prikazani su rezultati istraživanja koje se usredotočilo na promatranje razvoja sposobnosti učenika između 6. i 15. godine u stvaranju mentalne slike poznatoga geografskog područja, u obliku crteža (kognitivna ili mentalna karta). Istraživanje je provedeno analizom crteža usporednih mentalnih karata koje su napravili učenici osnovne škole. Podatci dobiveni istraživanjem zatim su statistički vrednovani na temelju određenih kriterija, kako bi se pronašli isti ili različiti stereotipi među crtežima. Rezultati istraživanja upućuju na postojanje značajnih razlika u sposobnosti grafičkoga prikazivanja poznatoga geografskog prostora, osvrćući se konkretno na dob (ili stupanj stečenoga iskustva) ili, u manjoj mjeri, i na spol učenika. Takvi ishodi su bitni s pedagoškoga stajališta jer rad s geografskim prikazom određenoga područja pripada osnovnim geografskim kompetencijama učenika