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Quality of Service Provision in Wireless Networks
Hnilička, Miroslav ; Janeček, Jan (advisor) ; Peterka, Jiří (referee)
This thesis aims at quality of service provisioning mechanisms in wireless packet networks. The main target of the work is multiple hops wireless networks area in which the problem is more general than in access networks. Theoretical part of the thesis analyses the problem and shows detailed insight of possible solutions. Practical part of the thesis focuses on more specific problem. Impacts of using different particular mechanisms on link and network layers are studied here, considering wireless mesh networks based on IEEE 802.11b technology (WiFi). Simulation model MeshQoS is designed on the basis of discrete simulation system OMNeT++. Inside this model, there are implemented two routing protocols - AODV defined by IETF and newly proposed hybrid opportunistic protocol OMR (OpportunisticMesh Routing). Results of experiments with this model helps to get the notion of the level of quality of services achievable in particular mesh networks configurations. They also show the positive effects of using opportunistic routing principle. In most scenarios OMR provide much lower latency, higher delivery probability and higher throughput.
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Cell shape simulation using cytoskeleton model
Horáček, Jaroslav ; Bílý, Tomáš (referee) ; Bálek, Martin (advisor)
This work is focused on computer modelling of cells' behavior. Emphasis is layed on simulating of cell shaping. The goal is to design theoretical structure, which suitably represents cytoskeleton of cell. Our model is based on Zygotic graph. It defines cell reactions to incoming stimulation from environment. Unlike previous models we newly add Fill graph and Granary graph to the Zygotic graph. In order to modelling of cell shaping we define membrane flexibility. We also define mechanism of Cytoplasmatic pulse. It is necessary for amoeboid movement modelling. We added new structure called Granary, which represents storage ability of cell. We use our model to simulate movement of amoeba cell. Another example shows white blood cell moving through blood vessel wall. We also attempt to simulate growth of cells inside closed environment.
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Numerical solution of compressible flow through a turbine cascade using various transition models
Nádvorník, M. ; Straka, P. ; Příhoda, Jaromír
The contribution deals with the numerical simulation of 2D compressible flow through a linear turbine blade cascade. Simulations were carried out by the in-house numerical code based on the two-equation k-omega turbulence model with the algebraic transition model and by the commercial software Fluent using the three-equation turbulence model including the transition model proposed by Walters and Cokljat. Predictions carried out for different Reynolds and Mach numbers cover the transition in the attached and separated flow as well. Predicted values of the loss coefficient and the flow outlet angle were compared with experimental data for the turbine cascade VS33.
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Evaluation of climate continentality
Mikolášková, Kateřina
The paper considers climate continentality from points of view of both temperature and precipitation. Main indices developed for climate continentality are present and compared and a suggestion of new index is made. The newly suggested index is based on daily means of temperature and considers influence of latitude on temperature distribution on the Earth. Linear regression was chosen as a function which describes the best the dependence of annual mean temperature on latitude. All indices are applied to the area of Europe and they are illustrated in maps created in ArcGIS and then evaluated. Evaluation is focused on newly suggested index. Trend of climate continentality from 1961 up to 2004 at station Prague - Clementinum is considered from points of view of all indices used in this paper. No significant trend is obvious but changes in a sub periods are noticeable.
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Mixing audio console with microphone preamplifier
Mecerod, Václav ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
Bachelor’s thesis on the theme "Mixing audio console with microphone preamplifier" deals with the design of an audio device for mixing signals from different sources. After a short theoretical introduction to issues mixing audio consoles, block diagram and circuit diagrams of each part are designed. These are redrawn into OrCAD Capture and using software PSpice simulations are performed. Configuration of the proposed mixing audio console is as follows: Two microphone preamplifiers with true differential inputs with switchable sensitivity, with the quad-band equalizer with tunable mid bands and adjustable delay. One line level input and one instrument input with three bands corrector. The output section consists of headphone and line level out.
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Visualization in vector spaces
Klímek, Jakub ; Hladík, Milan (referee) ; Fiala, Jiří (advisor)
The goal was to create a set of Java applets, which would serve as an addition to the teaching of Linear algebra. These applets make possible to compute with rational numbers, real numbers, complex numbers and Zp - integers modulo prime p using addition, subtraction, multiplication and division. It is also possible to compute with vectors of elements of those spaces using addition and subtraction of vectors and multiplication and division by scalar. In addition, the vector calculator can figure coordinates of a vector, determine a linearly independent subset of vectors and, when in standard scalar product space, figure an orthogonal projection onto a subspace generated by a set of vectors. The advantage of these applets is their ease of use simulating a classical handheld calculator.
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Interaction of flow and an elastic body
Kosík, Adam ; Feistauer, Miloslav (advisor) ; Knobloch, Petr (referee)
In the submitted work we are concerned with the numerical simulation of fluid flow and elastic body interaction. This is a coupled problem of the equations of two kinds, equations describing the flow and equations describing dynamical behaviour of the elastic body, which is partly surrounded by the fluid. These systems are coupled by suitable transmission conditions. The fluid flow is described by the Navier-Stokes equations, which are reformulated by the ALE method because of the deformation of the computational domain caused by the body movement. The deformation of the elastic body is described by the linear elasticity system with the generalized Hooke's law. We solve the problem by the finite element method. The developed methods are tested on the physical model of human vocal folds.
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The role of the radiological assistant in the radiotherapy of prostate cancer
Macháček, Jan ; Jirkovská, Michaela (referee) ; Malinová, Běla (advisor)
This bachelor's thesis "The Role of the Radiological Assistant in the Radiotherapy of Prostate Cancer" deals with a malignant disease of prostate which represents the most common type of cancer of adult men. In preface of my work, I concentrate on anatomy and function of prostate, epidemiology, disease symptoms and I so describe the way of diagnosis (PSA, DRE, TRUS, biopsy, radioisotopic scintigraphy, CT, MR and cystoscopy) here. The extent of tumour (staging) and clinical stage of disease (TNM classification, level of tumour differentiation) are very important at prostate cancer too. In realm of the curative strategy, I write about the surgical treatment, the possibility of radiotherapy, and about the hormonal treatment and the chemotherapy in the end. Especially I want to remark a daily working content of the radiological assistant at workplace of the radiological oncology (localization, planning CT examination, contouring, radiotherapy plan simulation, daily patient positioning and irradiation on linear accelerator) and equipment needed to radiation therapy (simulator, planning CT scanner, linear accelerator). In the end of my work I concentrate on the prognosis of prostate carcinoma and why it is important to do the preventive examination (screening) of this disease. The Faculty Library, Hospital Motol...
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Design of CMOS operational amplifiers
Němec, Tomáš ; Bajer, Arnošt (referee) ; Musil, Vladislav (advisor)
This work deals with issues of design and simulation of analog integrated circuit. The general aim is to design high-speed transconductance differentiating amplifier. The two stage operational – transconductance amplifier with compensation RC element is presented. This compensation method of zero nulling used prevents amplifier from oscillation.
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