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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimalizace tvaru krytu mulčovače z hlediska proudění vzduchu při různém uspořádání ostří / Optimizing the shape of the mower´s cover in terms of airflow at different arrangement of blades

Mihula, Lukáš January 2016 (has links)
The aim of this thesis is to create a contemporary overview on the issue mulching using contemporary Czech and foreign literature. In the chapter Mulching is described in this technology and distribution mulchers and theoretical principle of their function and possible uses. The section Methodology already contains the actual description of the construction of the model shredder Vertical axis and a theoretical description of the pressure measurement using pressure strips on the mower housing. The actual results of the measurements and their interpretation, see chapter "Measurement Results". Subsequent comparison of measured values is described in Comparison of results. In the last chapter, Economic assessment is a calculation of unit costs set mower with energy means.
2

Finitní průběhové tvary slovesné v odborném mluveném a psaném monologu. / Finite progressive forms in the academic spoken and written monologue

Bartekova, Barbora January 2014 (has links)
Page | 5 Abstract The MA thesis explores finite progressive forms in the academic spoken and written monologue. The English progressive forms generally appear much less frequently than the simple forms do. In academic spoken language 90 per cent of the finite verb forms consist of simple forms and the representation of simple forms is even higher in academic written language with 95 per cent of the finite verb forms being simple. The reasons for this distribution are related on the one hand to the specific meaning of the progressive forms, and on the other hand to the restricted compatibility of the progressive forms and some semantic verb classes. The present study considers both of these aspects in the attempt to describe the progressive forms in the academic spoken monologue (university lectures) and in the academic written language (advanced students' papers). The material is excerpted from two British academic English corpora, namely BASE (spoken language) and BAWE (written texts), 100 examples from each corpus. The material is analyzed at the formal, functional and discourse levels. The formal analysis deals with the distribution of tense forms, negation, the subject (person and animacy) and clause types. The functional criteria involve the semantic features of the verb and subject, as well as the...
3

Variabilita šířky letokruhu a konvenční hustoty dřeva vybraných dřevin po výšce kmene na Drahanské vrchovině

Becha, Lubomír January 2016 (has links)
The aim of the thesis is the determination of the spring and summer wood percentage, annual ring´s width and conventional density of the chosen woody plants and its dependence on the trunk´s level. For these purposes were researched 9 different trees. It was taken 10 wooden segments from the each chosen level of the trunk. It was chosen program WinDendro and it was made dendrochronological analyses and measurement of the spring and summer wood. It was used Olson´s mathematics figure for the conventional density calculation. In this calculation it is always used maximum level of the wood volume. The outcome is the number which is almost realistic figure of the conventional density change and structure change of the annuals´ rings. These outcomes are measured in the transection and cross section.
4

Analýza tvarů a frekvencí módů vzduchu uzavřeného v kabině automobilu / Analysis of natural frequencies and mode shapes of car cabin

Vokoun, Petr January 2009 (has links)
In analysis of natural frequencies and mode shapes of car cabin we shall investigate principle of measured values, we shall describe diferencies between analytic and FEM solution of simplified inside space. In next case we shall compute frequencies and mode shapes of sound inside car cabin of four different body and option of interference by one of them.
5

Sloupcové tvary jabloní, jejich charakteristika a praktické možnosti využití

Tomanová, Ladislava January 2017 (has links)
Valorization of the growth, harvesting and qualitative characteristics of apple tree varieties which are characterized by columnar growth pattern at ŠZP Žabčice. Focusing on the incidence of fungal diseases (apple scab, apple powdery mildew). Review of literature focusing on the characteristics of growth properties, harvesting data including the quality of fruits and their keeping.
6

Time-Varying Autoregressive Model Based Signal Processing with Applications to Interference Rejection in Spread Spectrum Communications

Shan, Peijun 13 August 1999 (has links)
The objective of this research is to develop time-varying signal processing methods for rapidly varying non-stationary signals based on time-varying autoregressive (TVAR) modeling, and to apply such methods to frequency-modulated (FM) interference rejection in direct-sequence spread spectrum (DSSS) communications. For fast varying non-stationary signal processing, such as the task to reject an FM interference that could chirp over the entire DSSS bandwidth in a symbol interval, an explicit description of the variation is necessary to form a time-varying filter. This is realized using the TVAR model, which is an autoregressive model whose coefficients are time-varying with the variation modeled as a linear combination of a set of known functions of time. In DSSS communications, when the strength of an interference - which could be a hostile jammer or overlaid communication signal - possibly exceeds the inherent spread spectrum processing gain, interference rejection is necessary to secure a usable bit-error-rate. The contributions of this research include: a) revealed the advantageous performance of TVAR model based instantaneous frequency estimation (TVAR-IF), which is expected to change the prevailing opinion that regards TVAR-IF as a poor estimator; b) proposed a time-varying Prony method to improve TVAR-IF at low SNR; c) proposed to use TVAR-IF for time-varying FIR notch filter based FM jammer suppression in DSSS communications; d) developed TVAR model based time-varying optimum filters, including the TVAR based Kalman filter (TVAR-KF) and the TVAR based Wiener filter (TVAR-WF); e) developed a TVAR-WF based formulation of FM interference soft-cancellation in DSSS communications; and f) proposed a TVAR based linear prediction error (TVAR-LPE) filter for soft-cancellation of FM interference in DSSS communications. For the interference rejection problem, our TVAR-IF controlled notch filter yields high processing gain close to that using the known IF and much higher than that using the WVD based IF estimate. Furthermore, unlike the IF based notch filter approaches, the proposed soft-cancellation methods utilize the full spectral information captured by the TVAR model. Our soft-cancellation approaches, including TVAR-WF and TVAR-LPE, maintain at least the DSSS system performance expected when no filtering is used, even under estimated conditions. The latter is in contrast to the notch filter based approaches, which may cause deterioration of overall system performance at low jammer-to-signal ratios. / Ph. D.
7

Modelos de séries temporais com coeficientes variando no tempo

Souza, Leandro Teixeira Lopes de 26 February 2009 (has links)
Made available in DSpace on 2016-06-02T20:06:02Z (GMT). No. of bitstreams: 1 2524.pdf: 3173626 bytes, checksum: 444d75f97bd088459e470db31df717a5 (MD5) Previous issue date: 2009-02-26 / Financiadora de Estudos e Projetos / In this work they are presented extensions of Auto Regressive and Auto Regressive Conditional Heteroscedasticity models with coefficients varying in time. These coefficients have been used as models for non stationary real time series, specially for financial series. The objective of this work is to present the models and the techniques involved in estimating time-varying coefficients, moreover, it is made an introduction to financial modeling and some suggestions in order to facilitate implementation and use of models with time-varying coefficients. The simulation studies and the application on real data showed that the models have great potential to be exploited in the analysis of non-stationary series. The suggestions in confidence band and forecasting for the Auto regressive models with time-varying coefficients enable the use of models in financial data and other series that show a non-stationary characteristic. The modified algorithm for estimation of ARCH models varying in time was to increase the rate of convergence. The creation of a method for forecasting for ARCH models require a deeper study, although the algorithm has shown promising results in simulation study, giving some evidences that it can be applied in real situation. Finally, the contributions in the creation of functions for a free software that facilitate the use and the analysis of the models studied and the use of the proposed methods. / No presente trabalho são apresentadas extensões dos modelos Auto Regressivo e Auto Regressivo Condicionalmente Heteroscedasticos com coeficientes variando ao longo do tempo. Estes têm sido utilizados como modelos para séries temporais reais não estacionárias, em especial as séries financeiras. O objetivo desse trabalho é apresentar os modelos e as técnicas envolvidas para estimar esses coeficientes que variam no tempo, além disso, é feito uma introdução a modelagem financeira e algumas sugestões para facilitar a aplicação e utilização dos modelos com coeficientes variando no tempo. Os estudos de simulação e a aplicação em dados reais mostraram que os modelos têm um grande potencial a ser explorados na análise de séries não estacionárias. As sugestões de banda de confiança e previsão para os modelos Auto Regressivos com coeficientes variando no tempo viabilizam a utilização dos modelos em dados financeiros e outras séries que apresentam uma característica de não estacionariedade. As modificações no algoritmo de estimação dos modelos ARCH variando no tempo foram para aumentar a taxa de convergência. A criação de um método para previsão dos modelos ARCH necessitam de um estudo mais profundo, porém o algoritmo mostrou resultados promissores no estudo de simulação, dando alguns indícios de que pode ser aplicada na prática. Por fim, as contribuições na criação de funções para um software livre que facilitam a utilização e a análise dos modelos estudados bem como a utilização dos métodos propostos.
8

Modelování vybraných geometrických parametrů lesních porostů z dat leteckého laserového skenování / Modelling of selected forest geometric parameters from airborne laser scannig data

Sedláčková, Oldřiška January 2014 (has links)
Modelling of selected forest geometric parameters from airborne laser scanning data Abstract The main aim of this work is to approximate the shape of a tree crown with mathematically describable 3D shape based on airborne laser scanning (ALS) data. And consequently derive geometrical parameters describing the tree from this model. Included in the work is a custom designed algorithm based on angular segmentation. Measured results of this algorithm are then compared to an algorithm based on RANSAC and field measurement. The first part of this work describes airborne laser scanning, its use to derive characteristics of forest stands and individual trees and the theory of tree crown modelling. The next part contains a description of both algorithms and presentation of results and field measurements. The conclusion summarizes and evaluates the outputs of the custom angular segmentation algorithm and discusses its possible modifications. Keywords: airborne laser scanning, tree height, crown width, crown height, crown cover, crown volume, crown shape, RANSAC
9

Ochrana prostorových ochranných známek a průmyslových vzorů / Protection of three dimensional trade marks and designs

Čech, Jakub January 2011 (has links)
Resumé Protection of Three-Dimensional Trade Marks and Designs The aim of this work was to examine the registration requirements of three- dimensional trade marks and designs, to compare the rights and protection conferred by each of these forms of intellectual property and to observe the interaction of trade mark and design when their subject matter is identical or similar. First part of this work focuses on the questions regarding the registration requirements of the three-dimensional trade marks. The work looks closely on what constitutes a sign and which absolute grounds for refusal of registration are mostly employed when dealing with the three-dimensional trade marks. Furthermore this work looks at exclusion of registration of certain types of shapes, on the requirement of good faith when applying for trade mark registration and briefly at the average consumer. The landmark cases cited in this part of the work are Dyson v Registrar of Trade Marks, Philips v Remington, Henkel v OHIM, Lego v OHIM and Lindt v Franz Hauswirth. Second part of this work looks at the definition of design and its relationship to product itself. It also looks at the background of design protection and closely at the registration requirements of designs, namely the novelty requirement, the individual character and exclusion of...
10

Comparison of soil microbial activity on sites with different forest management practices

Volánek, Jiří January 2016 (has links)
Presented thesis is focused on microbial activity of forest soils and aims at characterizing some of its parameters on sites with different silvicultural management practices. Coppice, coppice-with-standard and high forest stands were compared in terms of carbon and nitrogen content, content of microbial biomass, enzymatic activity and selected physical properties of soil. Study was conducted between September 2015 and April 2016 on pre-existing TARMAG II research plot near Soběšice, Brno, Czech Republic. Samples were collected during three different calendar seasons, allowing for seasonal dynamicity assessment of the studied parameters. Statistical evaluation detected significant effect of management type on potential respiration of studied soil samples as well as significant effect of seasonality on microbial biomass content in incubated samples, phosphatase activity in fresh soil samples, catalase activity in both fresh and incubated samples and potential respiration of studied samples. Results also show that the overall potential activity of urease and catalase was at its highest during the winter season.

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