• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 2
  • Tagged with
  • 10
  • 7
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 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

On Data Compression for TDOA Localization / Datakompression för TDOA-lokalisering

Arbring, Joel, Hedström, Patrik January 2010 (has links)
<p>This master thesis investigates different approaches to data compression on common types of signals in the context of localization by estimating time difference of arrival (TDOA). The thesis includes evaluation of the compression schemes using recorded data, collected as part of the thesis work. This evaluation shows that compression is possible while preserving localization accuracy.</p><p>The recorded data is backed up with more extensive simulations using a free space propagation model without attenuation. The signals investigated are flat spectrum signals, signals using phase-shift keying and single side band speech signals. Signals with low bandwidth are given precedence over high bandwidth signals, since they require more data in order to get an accurate localization estimate.</p><p>The compression methods used are transform based schemes. The transforms utilized are the Karhunen-Loéve transform and the discrete Fourier transform. Different approaches for quantization of the transform components are examined, one of them being zonal sampling.</p><p>Localization is performed in the Fourier domain by calculating the steered response power from the cross-spectral density matrix. The simulations are performed in Matlab using three recording nodes in a symmetrical geometry.</p><p>The performance of localization accuracy is compared with the Cramér-Rao bound for flat spectrum signals using the standard deviation of the localization error from the compressed signals.</p>
2

Posouzení asfaltového koberce drenážního a tenkého s asfaltem modifikovaným přísadou TecRoad / Evaluation of porous ashalt and acphalt conrete for very thin layers with asphalt modified by TecRoad additive

Kaška, Zdeněk January 2012 (has links)
This work is focused on the design and determination of the properties of porous asphalt and asphalt concrete for very thin layers with TecRoad addition. The water sensitivity, particle loss, stiffness, fatigue and low temperature characteristics and resistance to permanent deformation are determined for a description of mixtures properties. Subsequently, the mixtures are compared and recommendations for use in maintenance and reconstruction of roads are prepared.
3

On Data Compression for TDOA Localization / Datakompression för TDOA-lokalisering

Arbring, Joel, Hedström, Patrik January 2010 (has links)
This master thesis investigates different approaches to data compression on common types of signals in the context of localization by estimating time difference of arrival (TDOA). The thesis includes evaluation of the compression schemes using recorded data, collected as part of the thesis work. This evaluation shows that compression is possible while preserving localization accuracy. The recorded data is backed up with more extensive simulations using a free space propagation model without attenuation. The signals investigated are flat spectrum signals, signals using phase-shift keying and single side band speech signals. Signals with low bandwidth are given precedence over high bandwidth signals, since they require more data in order to get an accurate localization estimate. The compression methods used are transform based schemes. The transforms utilized are the Karhunen-Loéve transform and the discrete Fourier transform. Different approaches for quantization of the transform components are examined, one of them being zonal sampling. Localization is performed in the Fourier domain by calculating the steered response power from the cross-spectral density matrix. The simulations are performed in Matlab using three recording nodes in a symmetrical geometry. The performance of localization accuracy is compared with the Cramér-Rao bound for flat spectrum signals using the standard deviation of the localization error from the compressed signals.
4

Asfaltové směsi s vyšší životností za použití R-materiálu / Bituminous mixtures with a higher lifetime using recycled asphalt

Stromecký, Roman January 2019 (has links)
This diploma thesis deals with a project of asphalt mixtures with high stiffness modulus using R-material. The theoretical part describes the characteristics of these mixtures in the Czech Republic and in Switzerland. Further this part deals with the use of R-material in the Czech Republic and chosen other countries of the world, it also deals with the ways of recycling roads. The theoretical part also deals with the testing methods used. In the practical part two new asphalt mixtures of the high stiffness modulus type with the addition of 25 % R-material are suggested. As a base for these two mixtures a mixture of the high stiffness modulus type, which was taken from an asphalt mixing plant, was used. Tests were run on the binders and several functional tests (stiffness modulus, fatigue resistance, low temperature qualities) wer done on the suggested asphalt mixtures and also the mixture taken from the mixing plant. Consequently, the results were compared. The conclusion of the thesis is devoted to modelling a construction of a road using the program LayEps, which verified if the suggested mixtures could reduce the thickness of roads.
5

Inovativní asfaltové směsi pro netuhé vozovky s použitím R-materiálu / Inovative asphalt mixtures to flexible pavement structure with using reclaimed asphalt

Horáček, Daniel January 2020 (has links)
The diploma thesis is focused on the design and production of two innovative asphalt mixtures of the VMT 22 type into the base asphalt course. The newly produced blends contain modified binders, such as polymer modified bitumen (PMB) and Crumb rubber modified bitumen (CRMB). The theoretical part of the thesis describes the current state of the use of Reclaimed asphalt pavement in the base asphalt course. Furthermore, there are described types of asphalt mixtures for the base asphalt course are used in the Czech Republic and other countries. The conclusion of the theoretical part is devoted to the description of Reclaimed asphalt pavement (RAP), its storage and processing in a hot mix center. In the practical part of this thesis, there is described design and test of two High modulus asphalt mixture VMT 22, into which 25% RAP is dosed cold without rejuvenators. These asphalt mixtures are then subjected to functional tests (Stiffness of asphalt mixture test, Resistance to fatigue test, Low temperature properties of asphalt mixture test). The results of the functional tests are compared with the functional requirements in the Czech regulation TP 151. In the end of this thesis it is verified by means of the LayEps software that a suitable design of the asphalt mixture can significantly extend the road life.
6

Uplatnění pryžového granulátu v asfaltových pojivech a hutněných asfaltových směsích / Application of crumb rubber in bituminous binders and in bituminous mixtures

Dašek, Ondřej Unknown Date (has links)
Presented dissertation thesis is focused on the possibility of using the crumb rubber from waste tires for modification of paving grade bitumen. The resulting asphalt rubber can be used as an alternative to polymer modified bitumen in compacted bituminous mixtures. The theoretical part describes the rheological properties of asphalt binders and the history and today state of the art in the world and in the Czech Republic. The practical part of the work contains a description of the properties of chosen crumb rubbers and produced asphalt rubbers focused on their rheological properties and on change of these properties caused by the aging at high temperature. Subsequently, the chosen empirical and functional properties of bituminous mixtures with asphalt rubber are described. Laboratory properties of these mixtures were verified under real service conditions on 32 test sections. Based on the dissertation thesis results the preliminary technical specification of the Ministry of Transport (TP 148) and their following revision were approved. The conclusion of the work summarizes and highlights the results of the dissertation.
7

Inovativní asfaltové směsi pro obrusné vrstvy s použitím vyššího množství R-materiálu / Innovative Asphalt Mixtures for Wearing Course with a Higher Content of Reclaimed Asphalt Pavement

Spies, Karel Unknown Date (has links)
This master's thesis deals with the design of two asphalt mixtures for a wearing course containing 35 % R-material. The asphalt mixtures use a soft bitumen modified with crumb rubber (CRMB) or the unmodified soft binder itself with a penetration grade of 70/100. The work verifies the effect of crumb rubber as a bitumen modifier on the properties of the asphalt mixture with reclaimed asphalt pavement (RAP). At the same time, the work deals with the possibility of using higher amounts of reclaimed asphalt pavement only in combination with a softer binder without the use of rejuvenating additives. The properties of asphalt binders and mixtures are verified using suitable functional tests. Furthermore, the proposed mixtures and their results are compared from various perspectives. At the same time, the thesis in the theoretical part deals with the dosing of a reclaimed asphalt pavement into the asphalt mixture and describes the handling and use of reclaimed asphalt pavement in the Czech Republic and abroad
8

Návrh a posouzení směsi pro asfaltové vrstvy se zvýšenou odolností proti šíření trhlin (SAL) / Desing and evaluation of Bituminous Stress Absorbing Pavement Layer

Coufalík, Pavel January 2013 (has links)
This master's thesis deals with the possibility of special asphalt-rubber mixture using - Stress Absorbing Layer (SAL). In the theoretical part the SAL and test methods are described. In the practical part, several different mixtures are designed and selected mixtures were tested. Low-temperature characteristics, permanent deformations, bending tensile relaxation, stiffness modulus and fatigue properties were determined. Based on the test results the mixtures were compared and their benefit is evaluated according to Performance Pavement Design Method, the pavement structure was evaluated by using of computer programme LayEps.
9

Porovnání švédského a amerického konceptu návrhu směsí s CRmB / Swedish and US AR mixture design comparison

Puda, Adam January 2015 (has links)
This master's theseis deals with comparison of two design concepts for producting asphalt mixture with CRmB. These design concepts are from Sweden and USA. The theoretical part sets parameters for design of asphalt mixture and chracteristic tests. In the practical part test speciements of design asphatl mixture undergo performace tests that simulate climate and traffic load. Results are compared to mathematical model used in program LayEps.
10

Relaxace smykového napětí asfaltových pojiv v DSR / Shear stress relaxation of bituminous binders in DSR

Musil, Vladimír January 2015 (has links)
The thesis describes the relaxation properties of bituminous binders determined in dynamic shear rheometer (DSR). Paving bitumen, polymer modified bitumen (PMB) and crumb rubber modified bitumen (CRmB) were chosen for comparison. In order to describe the effects of ageing on asphalt binders relaxation properties, the laboratory simulation of ageing using RTFOT and 3xRTFOT method was performed. For each binder were simultaneously conducted tests of needle penetration, softening point and elastic recovery. Selected bitumens were used for the production of asphalt mixtures. The low-temperature properties tests (TSRST) were performed for these mixtures, when the results were compared to the relaxation properties of binders determined in the DSR.

Page generated in 0.0143 seconds