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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.
101

"Konsten att ta russinen ur kakan" : läs- och skrivundervisning i skolans tidiga år / "The art to pick the raisins from the cake" : - literacy in early years of school

Borg, Jenny, Nilmarkson, Sandra January 2015 (has links)
Syftet med föreliggande arbete är att undersöka hur lärare i ett urval skolor talar om sitt arbete med den tidiga läs- och skrivundervisningen i årskurs F-3. Undersökningens fokus kommer i huvudsak vara lärares beskrivning av undervisningens utformning samt vilka faktorer och modeller som ligger till grund för deras läs- och skrivundervisning. Utifrån syftet görs en enkätundersökning där lärare yrkesverksamma i årskurs F-3 deltar. Undervisningsmodellerna Bornholmsmodellen, LTG-metoden, Att skriva sig till läsning, Wittingmetoden och Whole language ligger till grund för en del av enkätens frågor. Undervisningsmodellerna presenteras under arbetets forskningsbakgrund och enkätsvaren redovisas under arbetets empiriska del. Avslutningsvis leds arbetet in i en diskussion med utgångspunkt i arbetets syfte, forskningsfrågor och enkätsvar. Undersökningen visar att lärare använder sig av olika modeller i den tidiga läs- och skrivundervisningen. De slutsatser som lyfts fram i diskussionen är betydelsen av att kombinera olika undervisningsmodeller för att tillgodose elevers individuella behov och förutsättningar. Det visar sig även i arbetets undersökning att lärares yrkeserfarenhet är en faktor till hur lärarna väljer att utforma den tidiga läs- och skrivundervisningen.
102

Top - Down Design eines universellen Kegelrollenlagermodells in Pro/MECHANICA

Kloninger, Paul 12 May 2011 (has links) (PDF)
In dieser Präsentation wird das universelle FE-Modell eines Kegelrollenlagers vorgestellt. Mittels eines Pro/ENGINEER-Layouts, basierend auf dem Top-Down Designkonzept, kann automatisch innerhalb einer kurzen Bearbeitungszeit ein geprüftes und lauffähiges FE-Modell eines Kegelrollenlagers abgeleitet werden. Dieses Modell kann z.B. in großen Getriebemodellen eingebaut werden, um eine quasistatische Betrachtung mit korrekten Lagersteifigkeiten zu ermöglichen.
103

Neue Methoden zur Verhaltensmodellierung und Charakterisierung eines analog-digital-Systems am Beispiel einer Phasenregelschleife

Hinz, Michael January 2008 (has links)
Zugl.: Braunschweig, Techn. Univ., Diss., 2008
104

Modulare Datentypdefinitionen und ihre Beziehungen zur Logik erster Stufe

Treinen, Ralf. Unknown Date (has links) (PDF)
Universiẗat, Diss., 1991--Saarbrücken.
105

Hierarchical optimization of large-scale analog, mixed-signal circuits based-on Pareto-optimal fronts

Zou, Jun January 2009 (has links)
Zugl.: München, Techn. Univ., Diss., 2009
106

Isolation, Purification and Characterization of Photosynthetic Membrane Proteins from Galdieria sulphuraria and Chlamydomonas reinhardtii

January 2010 (has links)
abstract: In oxygenic photosynthesis, Photosystem I (PSI) and Photosystem II (PSII) are two transmembrane protein complexes that catalyze the main step of energy conversion; the light induced charge separation that drives an electron transfer reaction across the thylakoid membrane. Current knowledge of the structure of PSI and PSII is based on three structures: PSI and PSII from the thermophilic cyanobacterium Thermosynechococcus elonagatus and the PSI/light harvesting complex I (PSI-LHCI) of the plant, Pisum sativum. To improve the knowledge of these important membrane protein complexes from a wider spectrum of photosynthetic organisms, photosynthetic apparatus of the thermo-acidophilic red alga, Galdieria sulphuraria and the green alga, Chlamydomonas reinhardtii were studied. Galdieria sulphuraria grows in extreme habitats such as hot sulfur springs with pH values from 0 to 4 and temperatures up to 56°C. In this study, both membrane protein complexes, PSI and PSII were isolated from this organism and characterized. Ultra-fast fluorescence spectroscopy and electron microscopy studies of PSI-LHCI supercomplexes illustrate how this organism has adapted to low light environmental conditions by tightly coupling PSI and LHC, which have not been observed in any organism so far. This result highlights the importance of structure-function relationships in different ecosystems. Galdieria sulphuraria PSII was used as a model protein to show the amenability of integral membrane proteins to top-down mass spectrometry. G.sulphuraria PSII has been characterized with unprecedented detail with identification of post translational modification of all the PSII subunits. This study is a technology advancement paving the way for the usage of top-down mass spectrometry for characterization of other large integral membrane proteins. The green alga, Chlamydomonas reinhardtii is widely used as a model for eukaryotic photosynthesis and results from this organism can be extrapolated to other eukaryotes, especially agricultural crops. Structural and functional studies on the PSI-LHCI complex of C.reinhardtii grown under high salt conditions were studied using ultra-fast fluorescence spectroscopy, circular dichroism and MALDI-TOF. Results revealed that pigment-pigment interactions in light harvesting complexes are disrupted and the acceptor side (ferredoxin docking side) is damaged under high salt conditions. / Dissertation/Thesis / Ph.D. Biochemistry 2010
107

Visual saliency computation for image analysis

Zhang, Jianming 08 December 2016 (has links)
Visual saliency computation is about detecting and understanding salient regions and elements in a visual scene. Algorithms for visual saliency computation can give clues to where people will look in images, what objects are visually prominent in a scene, etc. Such algorithms could be useful in a wide range of applications in computer vision and graphics. In this thesis, we study the following visual saliency computation problems. 1) Eye Fixation Prediction. Eye fixation prediction aims to predict where people look in a visual scene. For this problem, we propose a Boolean Map Saliency (BMS) model which leverages the global surroundedness cue using a Boolean map representation. We draw a theoretic connection between BMS and the Minimum Barrier Distance (MBD) transform to provide insight into our algorithm. Experiment results show that BMS compares favorably with state-of-the-art methods on seven benchmark datasets. 2) Salient Region Detection. Salient region detection entails computing a saliency map that highlights the regions of dominant objects in a scene. We propose a salient region detection method based on the Minimum Barrier Distance (MBD) transform. We present a fast approximate MBD transform algorithm with an error bound analysis. Powered by this fast MBD transform algorithm, our method can run at about 80 FPS and achieve state-of-the-art performance on four benchmark datasets. 3) Salient Object Detection. Salient object detection targets at localizing each salient object instance in an image. We propose a method using a Convolutional Neural Network (CNN) model for proposal generation and a novel subset optimization formulation for bounding box filtering. In experiments, our subset optimization formulation consistently outperforms heuristic bounding box filtering baselines, such as Non-maximum Suppression, and our method substantially outperforms previous methods on three challenging datasets. 4) Salient Object Subitizing. We propose a new visual saliency computation task, called Salient Object Subitizing, which is to predict the existence and the number of salient objects in an image using holistic cues. To this end, we present an image dataset of about 14K everyday images which are annotated using an online crowdsourcing marketplace. We show that an end-to-end trained CNN subitizing model can achieve promising performance without requiring any localization process. A method is proposed to further improve the training of the CNN subitizing model by leveraging synthetic images. 5) Top-down Saliency Detection. Unlike the aforementioned tasks, top-down saliency detection entails generating task-specific saliency maps. We propose a weakly supervised top-down saliency detection approach by modeling the top-down attention of a CNN image classifier. We propose Excitation Backprop and the concept of contrastive attention to generate highly discriminative top-down saliency maps. Our top-down saliency detection method achieves superior performance in weakly supervised localization tasks on challenging datasets. The usefulness of our method is further validated in the text-to-region association task, where our method provides state-of-the-art performance using only weakly labeled web images for training.
108

Savanna woody plant community and trait responses to bottom-up and top-down controls, with a specific focus on the role of mammalian herbivory / Réponses des traits spécifiques et des communautés ligneuses de savane aux processus de contrôle ascendant et descendant (bottom-up/top-down), avec une emphase sur le rôle des mammifères herbivores

Wigley, Benjamin Joseph 09 September 2013 (has links)
Les savanes sont des écosystèmes complexes pilotées par plusieurs mécanismes ascendant (ex: les nutriments du sol ou pluviométrie) ou descendant (ex: feu ou herbivorie), mais l'importance relative de ces mécanismes reste largement débattue. En particulier, le rôle des herbivores brouteurs (browsers) reste mal compris en tant que source de perturbation, et donc de force de pression descendante influant sur la dynamique des savanes. Dans cette étude, deux approches ont été développées pour aborder le rôle des perturbations dans la dynamique des savanes. Dans un première partie, j'ai utilisé une approche comparative inter-site pour explorer les réponses des communautés de plantes, et des principaux traits de ces plantes associés aux feuilles, branches, architecture et défense, aux variations de quatre facteurs : les nutriments dans le sol, la pluviométrie, la pression d'herbivorie et l'intensité du feu. Seize sites de savane, en Afrique du Sud et au Zimbabwe, ont été sélectionnés sur des gradients de chacun de ces facteurs. Les espèces ligneuses dominantes (>80 % de la biomasse) sur chaque site ont été identifiées et échantillonnées, afin de mesurer les traits des feuilles et des branches associés à l'appétence, architecture, ainsi qu'aux défenses physiques et chimiques de ces plantes. Des mesures ont également été faites pour estimer les effets des meso-brouteurs et mega-brouteurs. Des transects ont permis d'estimer la fréquence et l'intensité du feu sur chaque site, et l'effet sur les plantes. En préambule à l'analyse, et devant le manque de protocole standard pour estimer la fertilité des sols dans la littérature écologique, je propose une méthode et un échantillonnage afin de définir de manière robuste la fertilité des sols sur chaque site. Dans cette partie inter-site, huit traits principaux ont été comparés sur le gradient de qualité de sol et de pluviométrie, et bien que quelques relations statistiques existent entre les traits des feuilles, le sol et la pluviométrie, ces relations sont très faibles comparées à celle trouvées dans les méta analyses inter-biomes publiées dans la littérature. Cependant, ces approches interbiome sont dominées par des sites tempérés qui ont des niveaux de perturbations bien inférieurs à ceux des savanes africaines. L'évaluation des effets des meso-brouteurs et mega-brouteurs le long des gradients de sol et de pluviométrie sur vingt traits associés aux défenses structurelles et chimiques des plantes montre que les défenses structurelles sont plus corrélées aux caractéristiques du sol que les défenses chimiques, mais que seules les défenses structurelles sont fortement corrélées à l'impact par les brouteurs. Le niveau d'utilisation des plantes par les mesobrouteurs apparaît plus prévisible en fonction des traits des plantes que celui par les mégabrouteurs. Dans une deuxième partie présentent des résultats de deux études basées sur des expériences d'exclos. Dans le parc national de Kruger, la composition de la communauté, l'abondance et la démographie des ligneux dominants ont été estimées à l'intérieur et à l'extérieur de trois exclos de 40 ans, et les brouteurs apparaissent comme ayant un impact significatif sur la distribution, la densité et la structure des populations des espèces arbustives et arborées ayant des traits préférés : forte concentration en azote foliaire et faible teneur en défenses chimiques. L'interaction entre les effets des brouteurs et du feu semble aussi affecter le recrutement des juvéniles ligneux dans les grandes classes de taille. Dans le parc de Hluhluwe-iMfolozi, cinq exclos ont été utilisé pour tester l'effet des brouteurs sur l'architecture, la croissance, les défenses chimiques et structurelles des jeunes individus de sept espèces d'acacia. Des différences nettes apparaissent entre les espèces d'acacia de savane semi-aride et plus humide dans les traits associés à l'appétence, l'architecture et les défenses … [etc] / Savannas are complex ecosystems affected by several bottom-up (e.g. soil nutrient availability and rainfall) and top-down (e.g. fire and herbivory) drivers. However, the relative importance of bottom-up vs. top-down drivers in influencing savanna dynamics is still widely debated. Within the top-down (disturbance) category of drivers, the role of mammal browsers in particular in driving savanna functioning is still not well understood. Two approaches were adopted to determine the role of disturbance in savannas. Firstly, by using a comparative approach, I attempted to address the so-called ‘savanna problem’ by investigating how savanna woody plant community compositions and key plant traits relating to the leaves, stems, architecture, and defence are influenced by soil nutrient status, rainfall, fire and browsing. Sixteen sites were selected along gradients of these four drivers from savanna parks throughout South Africa and Zimbabwe. The dominant woody species (species that accounted for >80% of standing biomass) at each site were identified and sampled for the key leaf and stem traits relating to plant functioning, palatability, architecture, physical and chemical defences. Measurements were undertaken for each species in order to determine both meso-browser and mega browser impact. Transects were undertaken in order to determine the relative abundance and the effects of fire on each species at each site. Due to the current lack of standardized soil sampling protocols in the ecological literature, and uncertainty around the definition of what denotes a fertile or infertile soil, I propose a number of standardized protocols and sampled according to these established protocols in order to accurately determine the soil nutrient status at each site. Following this, the relationships between climatic variables and soil nutrients with both species means and community weighted means for eight key leaf traits were explored. Although some significant relationships were found between savanna leaf traits of woody plants, climate, soil nutrients and their interactions, these tended to be weaker than those found in meta-analyses. These broad-scale studies usually include sites from many biome types, many of which are from temperate regions where inherent levels of disturbance are typically much lower than in African savannas. The high levels of disturbance typically found in African savannas are thought to partially account for the high within site variability found in leaf traits and the weak relationships found between leaf traits, soil nutrients and rainfall. To assess the importance of resources vs. disturbance in savannas functioning, the effects of soil nutrients, rainfall, fire and both meso-browser and mega-browser impact on twenty savanna woody plant traits relating to plant palatability, chemical and structural defences were explored. Structural defences were found to be more strongly correlated with soil characteristics than chemical defences, while browser impact was found to be strongly correlated with structural defences but not with chemical defences. Actual browser utilisation tended to be more predictable for meso-browsers than mega-browsers. Secondly using an experimental approach, two sets of herbivore exclosures were utilized to directly test how mammal browsers influenced woody species distributions, abundance, population structure and plant traits relating to palatability and defence. The effects of three longterm herbivore exclosures in the Kruger National Park on savanna woody plant community compositions, population demographics and densities were determined. Browsers were found to have significant impacts on species distributions, densities and population structures by actively selecting for species with favourable traits, particularly higher leaf N. An interaction between browsers and fire which limited the recruitment of seedlings and saplings into larger size classes was also demonstrated… [etc]
109

Some aspects of error correction of programming languages

Frentiu, M. January 1976 (has links)
The thesis treats the problem of error correction in a context free language, and the design of an error correcting parser for the BASIC language. Two important things can be said about this thesis. First, it presents the problem of error correction in a context free language, and the existing results in the field. The concept of a context free language as a model for a programming language, and the definitions and results used later are presented or reviewed. A distance between two strings is defined and used to develop a “minimum distance error correcting parser”. Second, the thesis develops two global error correcting parsers. The first one is the top-down global error correcting parser, obtained by transforming Unger’s top-down parser into an error correcting one. Then the idea of Graham and Rhodes, of condensing the surrounding context of error, is extended, and a global simple precedence error correcting parser is obtained by analysing the whole content of the error, available from the input string. These parsers, and other known methods are then used to design and partially implement an error correcting parser for BASIC.
110

Caractérisation du glioblastome multiforme et suivi de ses chimiothérapies par imagerie MALDI couplée à l'approche top-down / Glioblastoma characterization and monitoring of its chemotherapies by MALDI imaging coupled to top down analysis

Ait-Belkacem, Rima 08 December 2014 (has links)
Le glioblastome est la forme la plus agressive des tumeurs du système nerveux central. Le traitement de référence consiste en l'exérèse chirurgicale, suivie d'une radiothérapie associée à une chimiothérapie concomitante et adjuvante par le témozolomide. Son bénéfice est démontré par une médiane de survie entre 12 et 14 mois. Le glioblastome est caractérisé par une population cellulaire hétérogène hautement infiltrante, angiogénique et résistante à la chimiothérapie. Dans le but d'optimiser l'effet des molécules thérapeutiques, un suivi de leur pharmacocinétique ainsi qu'une bonne caractérisation tumorale sont nécessaires. L'imagerie par désorption laser assistée par matrice en spectrométrie de masse (IMS MALDI) a été utilisée pour l'identification de marqueurs diagnostiques, pronostiques et prédictifs de réponse aux traitements. Elle a aussi permis de suivre la pharmacocinétique in situ des chimiothérapies.L'identification de protéines directement sur tissu par fragmentation en source a permis la mise en évidence de différents isotypes de tubuline, une des cibles majeures en thérapie anticancéreuse. Le couplage de cette stratégie d'identification à l'imagerie MALDI a permis d'identifier et de localiser dans des zones tumorales, des protéines impliquées dans la tumorigenèse. La distribution intra-tissulaire du bévacizumab et du témozolomide a été étudiée pour la première fois.Des marqueurs de réponse aux traitements ont ensuite été identifiés par comparaison des profils d'expression protéique de tumeurs avec et sans traitement. Ces résultats montrent l'intérêt de l'imagerie MALDI pour l'étude des chimiothérapies et permettent d'envisager son utilisation clinique future. / Glioblastoma is the most aggressive of the gliomas, a collection of tumors arising from glia or their precursors within the central nervous system. The current standard of care, comprised of surgical resection followed by radiation and the chemotherapeutic agent temozolomide, only provides patients with a 12-14 months survival period post-diagnosis. The glioblastoma is characterized by a heterogeneous population of cells that are highly infiltrative, angiogenic and resistant to chemotherapy. In order to optimize the therapy effect, a pharmacokinetic monitoring and a better understanding and characterization of tumor biology are needed. For this purpose, matrix assisted laser desorption/ionization imaging mass spectrometry imaging mass spectrometry (MALDI IMS) technology was applied to identify diagnostic, prognostic and predictive markers of therapy response; and to understand/follow the pharmacokinetic of chemotherapies. The top-down in-source decay strategy was used for protein identification directly on tissue. This strategy allowed tubulin protein isoforms distinction and identification, which is one of the main targets in cancer therapy. MALDI imaging coupled to ISD identified tumorigenesis proteins within tumor structures. Bevacizumab and temozolmide distribution was followed within brain tissue sections. For the first time a monoclonal antibody was deciphered on tissue. Finally, markers that predict therapy response were demonstrated by a comparison between protein expression profiles from tumors with and without chemotherapy treatment. These results highlight the interest of MALDI imaging for chemotherapy improvement and open the way for its use in the clinics.

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