National Repository of Grey Literature 8,260 records found  1 - 10nextend  jump to record: Search took 0.28 seconds. 

Analysis of Steady-State Operation of Induction Generators
Schreier, Luděk ; Bendl, Jiří ; Chomát, Miroslav ; Skalka, Miroslav
The paper deals with the problems associated with the estimation of the magnetizing current in generator operation of induction machines. The aim of this paper is to show possible rise of over-saturation of magnetic circuit in induction generators. The results may be used for more precise specification of parameters of an induction machine in different operating modes.

Building and use of smaller computer networks
Kyzivát, Marek ; Pinkas, Otakar (advisor) ; Šmejkal, Ivo (referee)
The thesis describes the initial state of the computer network Basic Schools and Kindergartens Ohradní (ZŠMŠ Ohradní) in Prague 4 and then its reconstruction, which I largely contributed. ZŠMŠ Ohradní consists of four pavilions and from one building on the other side of the street. The aim of this study is to assess the initial state of the network and point out the shortcomings that we discovered. We found deficiencies in the operation stress tests, measurements and data cabling overall analysis. Original networks connectivity was 100Mb/s. Together with a colleague, we are network administrators. Furthermore, I am going to introduce a new form of network, which has identified deficiencies improved, by using on newer technologies. I will describe its structure, address allocation, active and passive components, and operated services. New network is capable of 1Gb/s, and its spine is going to be 10Gb/s soon. Benefits of this reconstruction is faster, more stable and more modern network that will facilitate the work of employees of ZŠMŠ Ohradní. To these improvements, I have mainly contributed by measurements. I participated in the design and implementation of new form of data network. I collaborated with fellow Poc to the configuration of active elements and network services in reconstructed network.

Modelling, parameter estimation, optimisation and control of transport and reaction processes in bioreactors.
ŠTUMBAUER, Václav
With the significant potential of microalgae as a major biofuel source of the future, a considerable scientific attention is attracted towards the field of biotechnology and bioprocess engineering. Nevertheless the current photobioreactor (PBR) design methods are still too empirical. With this work I would like to promote the idea of designing a production system, such as a PBR, completely \emph{in silico}, thus allowing for the in silico optimization and optimal control determination. The thesis deals with the PBR modeling and simulation. It addresses two crucial issues in the current state-of-the-art PBR modeling. The first issue relevant to the deficiency of the currently available models - the incorrect or insufficient treatment of either the transport process modeling, the reaction modeling or the coupling between these two models. A correct treatment of both the transport and the reaction phenomena is proposed in the thesis - in the form of a unified modeling framework consisting of three interconnected parts - (i) the state system, (ii) the fluid-dynamic model and (iii) optimal control determination. The proposed model structure allows prediction of the PBR performance with respect to the modelled PBR size, geometry, operating conditions or a particular microalgae strain. The proposed unified modeling approach is applied to the case of the Couette-Taylor photobioreactor (CTBR) where it is used for the optimal control solution. The PBR represents a complex multiscale problem and especially in the case of the production scale systems, the associated computational costs are paramount. This is the second crucial issue addressed in the thesis. With respect to the computational complexity, the fluid dynamics simulation is the most costly part of the PBR simulation. To model the fluid flow with the classical CFD (Computational Fluid Dynamics) methods inside a production scale PBR leads to an enormous grid size. This usually requires a parallel implementation of the solver but in the parallelization of the classical methods lies another relevant issue - that of the amount of data the individual nodes must interchange with each other. The thesis addresses the performance relevant issues by proposing and evaluation alternative approaches to the fluid flow simulation. These approaches are more suitable to the parallel implementation than the classical methods because of their rather local character in comparison to the classical methods - namely the Lattice Boltzmann Method (LBM) for fluid flow, which is the primary focus of the thesis in this regard and alternatively also the discrete random walk based method (DRW). As the outcome of the thesis I have developed and validated a new Lagrangian general modeling approach to the transport and reaction processes in PBR - a framework based on the Lattice Boltzmann method (LBM) and the model of the Photosynthetic Factory (PSF) that models correctly the transport and reaction processes and their coupling. Further I have implemented a software prototype based on the proposed modeling approach and validated this prototype on the case of the Coutte-Taylor PBR. I have also demonstrated that the modeling approach has a significant potential from the computational costs point of view by implementing and validating the software prototype on the parallel architecture of CUDA (Compute Unified Device Architecture). The current parallel implementation is approximately 20 times faster than the unparallized one and decreases thus significantly the iteration cycle of the PBR design process.

Opera and new media
Gattringerová, Eliška ; KUSNJER, Ivan (advisor) ; PŘÍVRATSKÁ, Jiřina (referee)
The author is focusing on issues of opera in new media in her work. The introduction defines and decribes the concept of new medias. After that, author is especially focusing on presentation of operas which are broadcasted live into Czech cinemas, history of this relatively young phenomenon and its gradual develepment. As a next topic mentioned in the author's work is possibility to watch live broadcasts or records via particular websites of theatres. Finally, the author is describing internet websites, which are dealing with the opera issues, history, content and specifics. The author is summarizing other options how to present opera.At the end of the work, the author is trying to characterize meaning and benefits of the new medias for today's opera and opera audience.

Optical low dispersion rezonator as length sensor using optical frequency comb
Pravdová, Lenka ; Hucl, Václav ; Lešundák, Adam ; Lazar, Josef ; Číp, Ondřej
Ultra-high precis measurements are domain of lasers interferometers. An optical resonator measuring method using broad spectrum of radiation of an optical frequency comb was designed and experimentally verified at our workplace. The measuring of a quantity – a distance of resonator mirrors – is provided by its conversion to the value of repetition frequency of the pulse laser with mode-locked optical frequency comb. In this paper the comparison of the absolute scale of the optical resonator with an incremental interferometer scale is introduced. The incremental interferometer is implemented for verification of the optical resonator scale. The double beam incremental interferometer is operating at the wavelength of 633 nm and the measuring mirror with piezo actuator is used as one of its reflectors. It turns out that the major error signal is the reflection of the periodic nonlinearity of the incremental resonator scale. The relative resolution of our method reaches values up to 10-9 while maintaining measuring scale.

A pair of phase-synchronized semiconductor lasers for length metrology
Hucl, Václav ; Holá, Miroslava ; Čížek, Martin ; Řeřucha, Šimon ; Pham, Minh Tuan ; Pravdová, Lenka ; Lazar, Josef ; Číp, Ondřej
Semiconductor lasers are increasingly widespread in areas that have been so far dominated by He-Ne lasers. One of such areas is the length metrology, where He-Ne laser operating at 633nm wavelength is still a traditional source of coherent light for laser interferometers distance measuring. The advantages of semiconductor lasers compared with He-Ne laser are greater optical power and a significantly wider range of wavelength tuning without mode jumps. Another advantage is the possibility of frequency modulation of wavelength of the laser diode by directly changing the injection current. The benefits predetermine these laser diodes for the realization of dual-frequency laser sources for heterodyne interferometry. In this case, using a phase-locked loop technique the optical frequency of a laser diode is locked to the optical frequency of another laser diode with a certain frequency offset in the MHz order. In our contribution we present utilization of DBR laser diodes in implementing a dual-frequency laser source for laser interferometry with heterodyne detection.\n

Packet Classification Algorithms
Puš, Viktor ; Lhotka,, Ladislav (referee) ; Dvořák, Václav (advisor)
Tato práce se zabývá klasifikací paketů v počítačových sítích. Klasifikace paketů je klíčovou úlohou mnoha síťových zařízení, především paketových filtrů - firewallů. Práce se tedy týká oblasti počítačové bezpečnosti. Práce je zaměřena na vysokorychlostní sítě s přenosovou rychlostí 100 Gb/s a více. V těchto případech nelze použít pro klasifikaci obecné procesory, které svým výkonem zdaleka nevyhovují požadavkům na rychlost. Proto se využívají specializované technické prostředky, především obvody ASIC a FPGA. Neméně důležitý je také samotný algoritmus klasifikace. Existuje mnoho algoritmů klasifikace paketů předpokládajících hardwarovou implementaci, přesto však tyto přístupy nejsou připraveny pro velmi rychlé sítě. Dizertační práce se proto zabývá návrhem nových algoritmů klasifikace paketů se zaměřením na vysokorychlostní implementaci ve specializovaném hardware. Je navržen algoritmus, který dělí problém klasifikace na jednodušší podproblémy. Prvním krokem je operace vyhledání nejdelšího shodného prefixu, používaná také při směrování paketů v IP sítích. Tato práce předpokládá využití některého existujícího přístupu, neboť již byly prezentovány algoritmy s dostatečnou rychlostí. Následujícím krokem je mapování nalezených prefixů na číslo pravidla. V této části práce přináší vylepšení využitím na míru vytvořené hashovací funkce. Díky použití hashovací funkce lze mapování provést v konstantním čase a využít při tom pouze jednu paměť s úzkým datovým rozhraním. Rychlost tohoto algoritmu lze určit analyticky a nezávisí na počtu pravidel ani na charakteru síťového provozu. S využitím dostupných součástek lze dosáhnout propustnosti 266 milionů paketů za sekundu. Následující tři algoritmy uvedené v této práci snižují paměťové nároky prvního algoritmu, aniž by ovlivňovaly rychlost. Druhý algoritmus snižuje velikost paměti o 11 % až 96 % v závislosti na sadě pravidel. Nevýhodu nízké stability odstraňuje třetí algoritmus, který v porovnání s prvním zmenšuje paměťové nároky o 31 % až 84 %. Čtvrtý algoritmus kombinuje třetí algoritmus se starším přístupem a díky využití několika technik zmenšuje paměťové nároky o 73 % až 99 %.

Specifics of nurse care at the patient with MRSA on surgery from nurses' point of view.
KALÁBOVÁ, Miroslava
Title of the thesis: Specifics of the nursing care of patients with MRSA in the operating room from an anesthesiology nurse perspective. The aim of this thesis was to identify the specifics of nursing care of a patient with the MRSA in the operating room from the perspective of nurses working in the operating room. In the theoretical part focus is given to nursing care and its specifics for a patient with MRSA. Chapters relating to the regime measures, barrier nursing procedures and the use of specific aids, instruments and tools are treated in detail. The nursing care provided by anesthesia nurses and perioperative nurses in the operating room is defined. To reach the goals the quantitative research through questionnaires was chosen. The research sample consisted of anesthesia nurses and perioperative care nurses. Two types of standardized questionnaires were used, consisted of closed questions where respondents chose an appropriate answer, and from semi-open questions where respondents could specify their answers, and in one case open questions. Both questionnaires were completed by 12 test questions, where respondents had the choice of three possible answers, where one answer was correct. The results of the investigation are summarized in two types of graphs. Bar charts were used in questions where more answers were possible to mark, and for a better clarity the results were supplemented by tables. Results to other questions, where options were limited by one answer, are shown in percentages in pie graphs. Our thesis is very narrowly focused, because we concentrated on specifics of nursing care in a patient with MRSA in the operating room. We have determined the specifics of barrier nursing, nursing problems in a patient with MRSA in the operating room. We have discovered barrier nursing procedures in a patient with MRSA in the operating room. We have also succeeded in assessing the knowledge of nurses working in the operating room. The goal was met. An interesting finding was that most of anesthetic nurses and perioperative nurses had responded that the structural and technical arrangement in the operating room was not satisfactory in terms of barrier nursing of a patient with MRSA. This problem was expected, owing to the author´s experience in operating theaters. Thus Hypothesis 1 is confirmed. In total five hypotheses were stated, four of which were confirmed and one was disproved. The aim of the thesis was to draw attention to problems in the operating room during nursing a patient with MRSA. In the course of the research work there were no problems, however, it is necessary to mention the lack of literature on MRSA with regard to nursing care in operating theaters. The theoretical section of this thesis could be recommended as a resource for the education plan created on the basis of information collected and the results of this research. The results of the research survey may serve for general public, anesthesia and perioperative nurses who could benefit from the educational plan in practice while providing nursing care for a patient with MRSA.

Processing and utilization of by-products of brewery operations for energy purposes
Foltis, Marek ; Malaťák, Jan (advisor) ; Bradna, Jiří (referee)
The diploma thesis called Processing and using of co-products from brewery for energetic purposes. The thesis concerns it self with analysis current situation on field of processing waste from brewery industry. The thesis is focused on possibility of using brewery waste for energetic purposes. The thesis is divided in to two parts. First part features literature research of the topic, using all available resources. Second part features real data from element analysis done on samples of brewery waste and calculation of main characteristics of brewery waste. All calculations concerns them self in using brewery waste like substitution for fossil fuel. Goal of second part of thesis also is evaluate possibility of using brewery waste to make brewing more efficient.

Monitoring of operation mode in road transport
Vaverka, Jan ; Vaněk, Jiří (advisor) ; Miroslav, Miroslav (referee)
The aim of the work will assess whether current legislation is sufficient to work mode drivers in road transport and mutual comparison of process control components. In the case of deficiencies, the proposed solutions in the legislative change, but also the methodologies process control components.