Improvements of JPEG Format

Tato práce se zabývá algoritmy ztrátové komprese statického obrazu používanými standardem JPEG. Jsou zde podrobně představeny jednotlivé kroky komprese podle tohoto standardu. Mým cílem je představení a implementace vylepšení, která by vedla ke zvýšení kompresního poměru při zachování struktury standardu. Tato implementace je v závěru práce srovnána se standardní implementací a jsou navržena další možná vylepšení.This thesis deals with lossy still image compression algorithms used in JPEG standard. All compression steps according to this standard are described in detail. My objective is to introduce and implement improvements that would result in increased compression ratio while adhering to the structure of the standard. At the end of the thesis, the implementation is compared to standard implementation and additional possible improvements are proposed.

GPS Data Processing on iPhone

Tématem této bakalářské práce jsou moderní webové technologie a jejich využití v mobilních zařízeních se zaměřením na Apple iPhone. Aplikace pracuje jako organizér závodů. Mezi hlavní funkce patří tvorba a správa tratí, pomoc závodníkům při jejich absolvování a uchování rekordů, kterých dosáhli.Subject of this thesis is modern web technologies and their usage in mobile devices, with focus on the Apple iPhone. Aplication works as a race organizer. It's main functions consists of creation and management of tracks, support to racing users and storage of records.

Optimizing large applications

Both uppermost open source compilers, GCC and LLVM, are mature enough to link-time optimize large applications. In case of large applications, we must take into account, except standard speed efficiency and memory consumption, different aspects. We focus on size of the code, cold start-up time, etc. Developers of applications often come up with ad-hoc solutions such as Elfhack utility, start-up of an application via a pre-loading utility and dlopen; prelinking and variety of different tools that reorder functions to fit the order of execution. The goal of the thesis is to analyse all existing techniques of optimization, evaluate their efficiency and design new solutions based on the link-time optimization platform.Comment: 78 pages, diploma thesi

The energy intensity of the briquetting process in terms of profitability of waste treatment

ArticleModern agricultural industry is a source of a considerable amount of waste, which can come in various forms and states. Such waste, and not just agricultural waste in the form biomass, is highly desirable for further processing, depositing or utilising its energy potential. Briquetting technology is suitable for all these purposes. The briquetting press for industrial use is complex technical equipment. The economy of its operation has a major impact on the profitability of the produced briquettes and hence on the efficiency of waste and biomass processing as such. The paper deals with the energy demands of briquetting in terms of waste treatment and economic profitability of production in the whole context of waste processing as a whole

Shall Bekenstein's Area Law Prevail?

According to Bekenstein's area law, the black hole entropy is identified holographically - with one quarter of the horizon area. However, it is commonly believed that such a law is only valid in Einstein's theory and that higher curvature corrections generically give rise to its modifications. This is for example the case of black holes in Lovelock gravities, or their four-dimensional cousins in the recently discovered 4D scalar-tensor Gauss-Bonnet gravity where one naively 'finds' (classical) logarithmic corrections to the Bekenstein's law. In this note we argue that such logarithmic corrections originate from ignoring the shift symmetry of the 4D Gauss-Bonnet gravity. When this symmetry is properly taken into account, there is no longer any departure from the area law in this theory. Moreover, the first law remains valid upon modifying the black hole temperature, which can be derived via the Brown-York procedure but is no longer given by the surface gravity. Interestingly, we show that upon similar modification of the black hole temperature the area law can also prevail for black holes in higher-dimensional Lovelock gravities.Comment: 7 pages. Added appendix on recovering modified temperature via Brown-York procedure. Comments welcom

On the interpretation of the long-term cyclic period variations in RR Lyrae stars

Many RR Lyrae stars show long-term variations of their pulsation period, some of them in a cyclic way. Such behaviour can be attributed to the light-travel time effect (LTTE) caused by an unseen companion. Solutions of the LTTE often suggest very eccentric orbits and minimal mass of the companion on the order of several solar masses, thus, in the black hole range. We discuss the possibility of the occurrence of the RR Lyr-black hole pairs and on the case of Z CVn demonstrate that the LTTE hypothesis can be false in some of the binary candidates.Comment: 5 pages, 2 figures, published in the proceedings of "The RR Lyrae 2017 Conference", Niepolomice, Poland, 17-21 September 201