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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

Modelování lavinového ohrožení na území CHKO Jeseníky pomocí metod DPZ a GIS

Školoud, Libor January 2014 (has links)
This diploma thesis presents a comparison of the accuracy level of elevation data and 3D elevation countours and digital relief model 5. generation. These data are used in modeling of avalanche danger Velke Kotliny on the territory of CHKO Jeseniky. In ArcGIS 10.2 software model calculations are performed of break off zones using two equations, resulting in potential break off zones. The equation is based on the same basis, but it differs in approach of their authors inclusion of horizontal and vertical curvature of the terrain. Furthermore, the equations are different with their assigned values of individual variables, which may result in changing the source data and the associated change in details and accuracy. This facet follows modeling of avalanche paths in RAMMS software (Rapid Mass Movement System), wherein the input data are crucial for simulation of individual avalanches. Distinguishing of input date significantly affects the accuracy of the simulation of avalanche paths and calculating thier final values (pressure, speed, snow depth) in individual section of their paths.
2

Srovnání různých zdrojů digitálních modelů terénu v prostředí GIS pro hydrologické účely / The comparison of digital terrain model sources in GIS for hydrological purposes

Klempíř, Hynek January 2016 (has links)
This thesis deals with comparsion of digital terrain models from different sources processed in GIS for hydrological purposes. The diploma thesis is composed from several parts. First part sis consist of characteristics related to watershed and water flow, which are important for the understanding this work. The thesis also describes digitial terrain model, his creation and methods for obtainig digitial models. Then, there are described data sources from which is possible to gain digitial models. Next chapter is dedicated to the coordinate system. The last parts of this thesis describes drain alghorithms. Characteristic of this area was collected on experimental watershed Modrava II with the ESRI ArcGIS Desktop software that would mainly Spatial Analyst and ArcHydro extensions. The results of this diploma thesis can be concluded that the free digital terrain model SRTM 90 is not suitable for small regions with diverse terrain structure. Thereason is a small resolution model. Other terrain models provided free of chargé are sufficient even for small areas as the selected area of interest. Paid digitial models can al lbe established for the area of interest as appropriate.
3

Podklady pro tvorbu mapy pro orientační běh / Data for the Creation Orienteering Maps

Panchártek, Jan January 2013 (has links)
This thesis is about using airborne laser scanning data for making maps for Orienteering. In this thesis were used altimetry data DMR 4G and DMR 5G. These data are provided by ČUZK. The control measuring was made in choosen area to verify the accuracy. In this thesis is described procedure of data collection and their treatment. The results of this thesis are two illustrations of the orienteering maps.
4

Réponse du méthylome suite à l'exposition au froid chez une espèce à génome complexe : le maïs (Zea mays ssp. mays) / Methylome response following cold exposure in a complex genome species : maize (Zea mays ssp. mays)

Achour, Zeineb 15 May 2018 (has links)
La caractérisation moléculaire de la réponse des plantes aux contraintes environnementales permet de mieux comprendre les bases de l’adaptation des plantes à leur milieu, et pourrait aider à l’amélioration des plantes cultivées. L’épigénome est constitué de l’ensemble des marques présentes sur la chromatine et participe à la régulation de l’expression du génome, notamment au cours du développement. Il contribue aussi à la stabilité des génomes, notamment en empêchant la transposition des éléments transposables (ET). L’épigénome varie en fonction des contraintes environnementales et une meilleure compréhension de ces variations pourrait permettre d’apporter une vision nouvelle de l’interaction entre la plante et son environnement. Cependant, l’étendue des modifications de l’épigénome, le type de séquences affectées et les mécanismes impliqués restent à déterminer. Dans ce cadre, j’ai analysé l’impact du froid sur le méthylome du maïs, une plante à génome complexe riche en ET. Dans un premier axe, j’ai analysé le méthylome d’un génotype sensible au froid, B73, par séquençage haut-débit d’ADN traité au bisulfite de sodium (BS-seq). Cette analyse comparative entre plantes « stressées » et « non stressées » a été menée (i) à l’échelle chromosomique, sans a priori sur le niveau de variation de méthylation de l’ADN et (ii) à l’échelle locale (régions différentiellements méthylées, ou « DMR ») en fixant des niveaux de variations forts (>10%). Ces deux types d’analyses ont permis de montrer que le froid déclenche une hyperméthylation à l’échelle du génome, à laquelle se superposent des hyper- et hypométhylations à l’échelle locale. Ces variations sont observées pour les trois contextes de cytosine et dans différentes régions génomiques associées aux gènes et aux ET. Ceci suggère l’activation parallèle de plusieurs mécanismes de régulation de la méthylation de l’ADN en réponse au froid. Dans un second axe, j’ai suivi ces DMR au cours du développement et dans la descendance afin d’étudier leur transmission, en lien avec leur localisation génomique et les contextes de cytosine affectés. Dans un troisième axe, j’ai étudié le lien entre variations de méthylation et sensibilité au froid en comparant la réponse du méthylome chez trois génotypes de maïs (B73, F2 et F331) présentant une réponse phénotypique contrastée pour ce caractère. / Molecular characterization of plant response to environnemental constraints allows to both better understand plant adaptation and help crop improvement. The epigenome is composed of chromatin marks and participates to the regulation of genome expression, notably through development. It is also involved in genome stability, essentially by preventing the transposition of transposable elements (TE). The epigenome can be modified by environmental cues and better understanding this variation could give new insights on the interaction between the plant and its environnement. However, the extent of this modification, targeted sequences and underlying mecanisms remain to be elucidated. In this context, I analyzed the impact of cold on the methylome of maize, a plant with a complex genome with high proportion of TEs. In a first part, I analyzed the methylome of a cold-sensitive genotype, B73, using whole genome bisulfite sequecing (BS-seq). This comparative analysis between “stressed” and “unstressed” plants was carried out (i) at the chromosome scale, without a priori definition of a DNA methylation difference and (ii) at a localized scale (Differentially Methylated regions, « DMRs ») using high minimum methylation difference rate (10%). These two types of analysis revealed that cold triggers hypermethylation at the genome scale, as well as. hyper-and-hypo-methylation at the local scale. These variations were observed in the 3 contexts of cytosine and occur in different genomic regions associated with genes and TEs. This suggests the parallel activation of different regulatory pathways in response to cold. In a second part, I focused on following-up methylation changes through development and in the progeny in conjunction with the genomic sequences and the cytosine context involved. In a third part, I studied the relationship between methylome variations and cold sensitivity by comparing the methylomes of three maize genotypes (B73, F2 and F331) with a contrasted phenotypic response to cold.
5

Bio-statistical approaches to evaluate the link between specific nutrients and methylation patterns in a breast cancer case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) study / Approches bio-statistiques pour évaluer le lien entre nutriments et profils de méthylation du cancer du sein dans l’étude prospective Européenne sur le Cancer et la Nutrition (EPIC)

Perrier, Flavie 13 September 2018 (has links)
De par les centaines de milliers de données qui les caractérisent, les bases de données épigénétiques représentent actuellement un défi majeur. L’objectif principal de cette thèse est d’évaluer la performance d’outils statistiques développés pour les données de grande dimension, en explorant l’association entre facteurs alimentaires reliés au cancer du sein (CS) et méthylation de l’ADN dans la cohorte EPIC.Afin d’étudier les caractéristiques des données de méthylation, l’identification des sources systématiques de variabilité des mesures de méthylation a été effectuée par la méthode de la PC-PR2. Ainsi la performance de trois techniques de normalisation, très répandues pour corriger la part de variabilité non désirée, a été évaluée en quantifiant l’entendu de variabilité attribuée aux facteurs de laboratoire avant et après chaque méthode de correction.Une fois la méthode de normalisation la plus appropriée identifiée, la relation entre le folate, l’alcool et la méthylation de l’ADN a été analysée par le biais de trois approches : une analyse individuelle des sites CpG, une analyse de DMR et la régression fused lasso. Les deux dernières méthodes visent à identifier des régions spécifiques de l’épigénome grâce aux corrélations possibles entre les sites proches. La méthylation globale a aussi été utilisée pour étudier la relation entre méthylation et risque de CS.Grâce à une évaluation exhaustive d’outils statistiques révélant la complexité des données de méthylation de l’ADN, cette thèse offre un aperçu instructif de connaissances pour les études épigénétiques, avec une possibilité d’application de méthodologie similaire aux analyses d’autres types de données -omiques / Epigenetics data are challenging sets characterized by hundreds of thousands of features. The main objective of this thesis was to evaluate the performance of some of the existing statistical methods to handle sets of large dimension data, exploring the association between dietary factors related to breast cancer (BC) and DNA methylation within the EPIC study.In order to investigate the characteristics of epigenetics data, the identification of random and systematic sources of variability of methylation measurements was attempted, via the principal component partial R-square (PC-PR2) method. Using this technique, the performance of three popular normalization techniques to correct for unwanted sources of variability was evaluated by quantifying epigenetics variability attributed to laboratory factors before and after the application of each correction method.Once a suitable normalization procedure was identified, the association between alcohol intake, dietary folate and methylation levels was examined by means of three approaches: an analysis of individual CpG sites, of differentially methylated regions (DMRs) and using fused lasso regression. The last two methods aim at the identification of specific regions of the epigenome using the potential correlation between neighboring CpG sites. Global methylation levels were used to investigate the relationship between methylation and BC risk.By performing an exhaustive evaluation of the statistical tools used to disclose complexity of DNA methylation data, this thesis provides informative insights for studies focusing on epigenetics, with promising potentials to apply similar methodology to the analysis of other -omics data
6

License-free communication using digital mobile radio standards and spread spectrum

McQuay, Colter James Alexander 17 July 2019 (has links)
The concept of using spread spectrum and open radio standards to provide license-free, short range Peer-to-Peer (P2P) communication is explored. This research makes use of the Time Compression Overlap Add (TC-OLA) algorithm to transparently spread the spectrum of the Digital Mobile Radio (DMR) standard; this allows for reuse of existing hardware, software, and expertise relating to this well established protocol. Initial high level hardware designs of a communication device established the need to implement a proof of concept system which could be validated against Radio Frequency (RF) regulations. This proof of concept system was constructed using a hardware implementation of DMR processed through custom TC-OLA blocks in GNU Radio (GR). A spectral and performance analysis of this system was performed, showing that this approach has several benefits over existing license free communication options. / Graduate / 2020-07-11
7

Isotopic Characteristics of Asian Dusts and Their Physicochemical Succession of Long-Range Transport

Chin, Wei-Min 04 September 2009 (has links)
ABSTRACT In this study, we conducted an intensive sampling of Asian dusts at Pescadores Islands for heavy Asian continental sandstorms (ACS) from February 22 to March 6, 2008. To investigate the succession of anthropogenic and natural pollutants for the ACS transportation, PM2.5 and PM2.5-10 were sampled by two dichotomous samplers once every four hours during the ACS periods, and furthermore analyzed their physicochemical properties, including mass concentrations, particle size distribution, water-soluble ionic species, carbonaceous contents, and metallic contents. Experimental results indicated that it was mainly fine particles (PM2.5) prior to the ACS, and the percentage of anthropogenic species (i.e., SO42-, NH4+, NO3-, Zn, Mn and OC) increased dramatically. However, it changed to coarse particles while the ACS overwhelming, and the percentage of crustal/marine species (i.e., Cl-, Na+, Ca2+, Mg2+, Ca, Al, Mg and EC) increased. After the ACS, the concentrations of all species decreased substantially. However, the percentage of Cl- and Na+ increased, suggesting that sea breeze has constant influences on local suspended particles. In addition to the analysis of physicochemical properties of Asian dusts, this study applied a HYSPLIT MODEL to figure out the transportation routes and the source regions of the ACS. Backward trajectory analysis showed that the ACS was originated from the east portion of Inner Mongolia, namely the Onqin Daga Sandy Land and the Horqin Sandy Land. Moreover, seventeen soil samples were collected from the Tengger Desert, the Mu Us Desert, the Onqin Daga Sandy Land, and the Horqin Sandy Land in Inner Mongolia during the year of 2005. The soil samples were resuspended in a resuspension chamber and then collected by a dichotomous sampler. This study focused on PM2.5-10 particles that mainly influence the downwind regions, and then took the ACS samples and the resuspended soil samples to measure the Sr isotopic characteristics of 87Sr/86Sr ratios by a multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). To characterize the isotopic properties of resuspended dust particles from the ACS source regions in northern China, and to correlate Asian dusts at the downwind regions of ACS with the source regions by Duncan¡¦s Multiple Range Test (DMR). The DMR results showed that the ACS was probably originated from the east portion of Inner Mongolia, namely the Onqin Daga Sandy Land and the Horqin Sandy Land, which concurred with the backward trajectory analysis.
8

Určení záplavového území a hydrotechnické posouzení objektů na vybraném úseku vodního toku Mastník na podkladě DMR 5. generace / Determination of floodplains and hydrotechnical assessment of Mastník water flow based on the DMR 5G data

Čápová, Pavlína January 2016 (has links)
This work engages in the watercourse called Mastník. It focuses on the determination of flooded areas for couple of series (Q5, Q10, Q50, Q100) and hydro-technical assessment of particular objects. The chosen section is situated on cadastral area of town Sedlčany in the Central Bohemia region. Its length is 1.973 kms and there is located 5 water management objects reaching to the flow profile of the watercourse. The data for this dissertation has been gained by the Czech State Administration of Land Surveying and Cadaster. It is about the digital relief of the 5th generation of aerial laser scanning. The laser rays are not capable of penetration the water surface, and thus describe the shape of the water-sources bed. So the tool called CroSolver was used to dig the water-sources bed. Then the hydrodynamic model has been created in program called HEC-RAS. From the results of hydrodynamic model then was evaluated the real water-technical state of the object. The outgoing data (dots defining the flood range to the surroundings) was after then inserted to the program ArcMap. Here the flood lines and from them the flood zones were created based on the particular series of the flows.
9

Tvorba databáze krasových jevů na území ŠLP Křtiny z dat leteckého laserového skenování

Balková, Marie January 2016 (has links)
This diploma thesis deals with description of the karst and its typical phnenomenons with emphasis on surface figures sinkholes. Further, it dicribes the airborne laser scanning (ALS) technology, data collection and processing procedure and utilization for the puropose of terrain depressions indentification based on the researches and processes of foreign experts. From these available studies, the most suitable methodics is chosen and applied to Digital Elevation Model of 5th generation (DEM 5G) data. The results of this aplication are compared with available sinkholes databases kept in the PLA Moravian Karst office and own terrain research.
10

Stabilitní poměry sesuvného svahu v údolí Jíloveckého potoka v Semilech / Slope stability of Jizera river valley slopes in Semily region

Kujan, Ondřej January 2016 (has links)
The thesis deals with slope stability of a landslide "U Čtrnácti pomocníků", which is located in the north-eastern part of the city Semily in the Liberec district. The thesis is divided into theoretical and practical part. The theoretical part was carried out literature search on the issue and the natural conditions around the wider area of interest. The practical part consists of individual sections within which the research were conducted archival documentation, mapping areas of interest, own technical work, sampling and geophysical measurements and laboratory work and stability calculations. Also the engineering geological model of the landslide was created. The results of the practical part are used as the basis for the final engineering geological evaluation of this area.

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