References of "Doctoral thesis"
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See detailStrafgesetzlichkeit als völkerstrafrechtliches Legitimationsprinzip
Deffert, Dietmar UL

Doctoral thesis (2007)

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See detailGlobal and Local Gravity Field Recovery from Satellite-to-Satellite Tracking
Weigelt, Matthias UL

Doctoral thesis (2007)

The main objective of this thesis is the gravity field recovery using satellite-to-satellite tracking methods. Based on new technologies like the global positioning system and accelerometers satellite-to ... [more ▼]

The main objective of this thesis is the gravity field recovery using satellite-to-satellite tracking methods. Based on new technologies like the global positioning system and accelerometers satellite-to-satellite tracking yields a dramatic improvement in the de- termination of the Earth gravity field. Two dedicated satellite missions, namely the CHAllenging Minisatellite Payload (CHAMP) and the Gravity Recovery And Climate Experiment (GRACE) are underway. This work describes the processing of the satel- lite data from CHAMP and GRACE based on the energy balance approach. The first part discusses the global gravity field recovery from CHAMP. Specifically, it aims at a reprocessing of kinematic position data and at a refinement of the data processing strategies. Although the energy balance approach is theoretically simple, its imple- mentation proved to be quite challenging. By refining the processing techniques an improvement of up to 30\% is reached for the low degree spherical harmonic coefficients. Nevertheless, the solutions still depend strongly on the variability of the groundtrack. The quality of the monthly solutions can vary up to one order of magnitude. To ad- dress this challenge, an in-depth analysis gives new insight into the phenomenon, and a new and unique combination method with GRACE data is presented, which yields a more homogeneous set of solutions and reaches the edge of the recoverability of a time-variable gravity signal from high-low satellite-to-satellite tracking missions. In the second part the energy balance approach is applied to the GRACE mission. Pre- vious attempts of expressing the kinetic energy in terms of the K-band measurement make use of an approximation. In this work, an exact representation is introduced and is validated by simulations. In the third part, the aim is to make optimal usage of the data distribution in the high latitude area. For this, interpolation and downward continuation techniques are investigated and an improvement, compared to the global solutions, is achieved. Overall, the analysis provides new and valuable insight into the data processing of satellite-to-satellite tracking data using the energy balance approach. [less ▲]

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See detailRelating to Nature: The Performative Spaces of Icelandic Tourism
Olafsdottir, Gunnthora UL

Doctoral thesis (2007)

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See detailZum Tragverhalten von Flachdecken mit integrierten hohlkastenförmigen Stahlprofilen
Schäfer, Markus UL

Doctoral thesis (2007)

Due to the demand for slim constructions and improvement of erection methods on building site composite slim-floor systems become more important. In the present european and national codes do not include ... [more ▼]

Due to the demand for slim constructions and improvement of erection methods on building site composite slim-floor systems become more important. In the present european and national codes do not include complete design rules for slim-floor constructions. Therefore the objective of this thesis is concentrated on the development of design rules for slim-floor girders. During the erection stage the elastic design resistance of the steel girder is decisive. Because of the slight plate thickness and sometimes considerable torsional stressing the influence of the shape deformation becomes more important and has to be considered. In this approach the steel sections are filled with concrete in the final state. Thereby the concrete in the openings, arranged in the web or upper flange, work concurrently as concrete dowels. The determination of moment resistance follows the rules for composite structures, respectively whereas in many cases the strain limited design is relevant and additionally the influences from transverse bending in the bottom flange have to be considered. Because of the sheathing of the concrete encasement by the steel section a hybrid truss model with a compression strut in the concrete section is developed, increasing the shear of the section. In case of fire, the directly flamed bottom flange can be substituted by longitudinal reinforcement bars and a high fire resistance period can be realized without any additional activities. For the analysis in case of fire, a design-method is extracted according to EN 1994-1-2. Based on a transient analysis, thermal analytic functions are developed to describe the temperature distribution in the cross section. The crack behaviour of the concrete slab has already a significant impact on the girder deformation in the serviceability limit state. The concrete flange adopts a remarkable part of the bending-moment. Compared to general treatment of common composite girders, the neglecting of these bending influences can lead to unrealistic camber of the girder. Therefore, an approximation procedure is derived that considers the bearing of the resilience of composite connector and the crack behaviour on the structure deformation. [less ▲]

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See detailUse of commercial simulation software for analyzing the dynamics of an injection-molding clamp unit
Hostert, Claude UL

Doctoral thesis (2006)

Today, the interest in integrated dynamic analysis of mechatronic systems increases. Different approaches are possible depending on the nature of the system, on the required complexity of the model, or ... [more ▼]

Today, the interest in integrated dynamic analysis of mechatronic systems increases. Different approaches are possible depending on the nature of the system, on the required complexity of the model, or simply on the tools available to the engineer. During this work, the aim was to implement specialized commercial simulation software packages and to combine them in order to simulate the dynamic behavior of mechatronic systems as for example an injection molding machine. The multi-body simulation software is the backbone of the current analysis as it inherently models large non-linear motions. It is possible to account for the flexibility of components in the MBS model if necessary. Furthermore, other simulation codes were used to model the hydraulic and controls systems. The case studies show the interest and the potential of a combined analysis of mechatronic systems. Once the different sub-models, generated with the adequate simulation tool, have been successfully linked and validated by measurements, various scenarios can be simulated and analyzed. The model provides the engineer with an additional insight into the overall system and thus with a better understanding of its dynamic characteristics. The interactions between the subsystems, which may be of very distinctive nature, can be investigated. Generally, it is difficult to predict such relations intuitively. Finally, the model allows to simulate with different design parameters and to asses the effect of modifications to these on the overall performance of the machine. This helps to identify the significant parameters that are crucial for an optimized functioning. [less ▲]

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See detailDie Rolle der Landwirtschaft in der Eigenständigen Regionalentwicklung der Region "West" Irlands
Sprenger, Birte UL

Doctoral thesis (2005)

Die Bedeutung der Landwirtschaft für die Eigenständige Regionalentwicklung unter Berücksichtigung der Multifunktionalität der landwirtschaft am Fallbeispiel der peripherem agrarstrukturell geprägten ... [more ▼]

Die Bedeutung der Landwirtschaft für die Eigenständige Regionalentwicklung unter Berücksichtigung der Multifunktionalität der landwirtschaft am Fallbeispiel der peripherem agrarstrukturell geprägten region West in der Republik Irland wird untersucht und bewertet. [less ▲]

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See detailFamily adjustment to disability and chronic illnessin children
Pit-Ten Cate, Ineke UL

Doctoral thesis (2004)

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See detailDie bakterielle Signalverarbeitung am Beispiel des Sucrose Phosphotransferasesystems in Escherichia coli : Modellierung und experimentelle Überprüfung
Sauter, Thomas UL

Doctoral thesis (2003)

Bacterial signal processing was investigated concerning the sucrose phosphotransferase system (sucrose PTS) in the bacterium Escherichia coli as an example. The about 20 different phosphotransferase ... [more ▼]

Bacterial signal processing was investigated concerning the sucrose phosphotransferase system (sucrose PTS) in the bacterium Escherichia coli as an example. The about 20 different phosphotransferase systems (PTSs) of the cell fulfil besides the transport of various carbohydrates, also the function of one signal processing system. Extra- and intracellular signals are converted within the PTS protein chain to important regulatory signals affecting e.g. carbon metabolism and chemotaxis. A detailed dynamical model of the sucrose PTS was developed describing transport and signal processing function. It was formulated using a detailed description of complex formation and phosphate transfer between the chain proteins. Model parameters were taken from literature or were identified with own experiments. Using a formal algorithm including cluster analysis, PTS and glycolysis could be identified as biological functional units with limited autonomy. Simulation studies together with experimental hints showed that the dynamic behaviour of phosphate transfer in the PTS runs within one second. Therefore a description of steady state characteristics is sufficient for describing the signaling properties of the sucrose PTS. A steady state characteristic field describes the degree of phosphorylation of the PTS protein EIIACrr as a function of the input variables extracellular sucrose concentration and intracellular PEP:pyruvate ratio. The model has been validated with different experiments performed in a CSTR using an sucrose positive Escherichia coli W3110 derivative. A method for determining intracellular metabolite concentrations has been developed. A sample preparation technique using a boiling ethanol buffer solution was successfully applied. The PTS output signal degree of phosphorylation of EIIACrr was also measured. Steady state conditions with varying dilution rate and dissolved oxygen concentration and dynamical variations applying different stimuli to the culture were considered. Pulse, and stop feeding experiments with limiting sucrose concentrations were performed. Simulation and experimental results matched well. The same holds for the expanded sucrose PTS and glycolysis model. [less ▲]

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See detailDas modale Zeitgedächtnis
Klapproth, Florian UL

Doctoral thesis (2003)

Detailed reference viewed: 57 (2 UL)
See detailBenetzung in ternären Flüssigkeitsmischungen
Schilling, Tanja UL

Doctoral thesis (2001)

Detailed reference viewed: 78 (5 UL)
See detailMotologie zwischen objektiver und subjektiver Sinnesphysiologie
Wantz, Marc UL

Doctoral thesis (2000)

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See detailAggregation Operators for Multicriteria Decision Aid
Marichal, Jean-Luc UL

Doctoral thesis (1998)

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See detailDiscrete element analysis of granular materials
Van Baars, Stefan UL

Doctoral thesis (1996)

Discrete Element Analysis of Granular Materials During oil and gas production, several years after drilling a borehole, sand particles and small sandstone particles start to break away from the borehole ... [more ▼]

Discrete Element Analysis of Granular Materials During oil and gas production, several years after drilling a borehole, sand particles and small sandstone particles start to break away from the borehole surface. These particles can damage the transport pipes and other equipment in a short period of time. By simulating this borehole behaviour with the thick-walled cylinder test, four phenomena were found which cannot be explained by conventional continuum mechanics: 1. Despite the compressive stress, failure occurs on the micro level due to tension cracks. 2. These cracks are not diagonal to, but parallel to, the borehole surface. 3. These cracks cause two diametrically opposite breakouts. 4. The functional failure of the borehole starts at a higher radial pressure than predicted. In 1979, Cundall developed a computer model, based on the basic elements of granular materials, i.e. the grains themselves and their interactions, to describe the behaviour of these materials. Lindhout tried, in 1992, to use this model to describe the cylinder test. Due to compaction problems, stability problems and the large computational time, this could not be achieved. Therefore a new model was developed by the author, which does not use the equations of motion, but the equations of equilibrium, to calculate the new grain positions. This model can be used both for non-cohesive grains (sand) and for cohesive grains (sandstone). The results can generally be described by an advanced Mohr-Coulomb model. However, there are a few exceptions. Firstly, during loading of a granular structure, many contacts between the grains will collapse, not due to shear deformation as Coulomb suggests, but due to tension failure. Secondly, these micro cracks always occur in the direction of the major principal stress, which might be another direction than the observed failure surface. In this way, the axial micro cracks form a diagonal failure surface during a biaxial test, but the axial micro cracks in a cylinder test may form a failure surface parallel to the borehole surface. During the formation of natural sandstone, the difference between the horizontal and vertical stress causes anisotropy in the strength behaviour of this material. This or other anisotropies may explain the diametrically opposite breakouts. The conclusion that a borehole fails at a higher radial pressure than predicted, originates from the definition difference between local failure and functional failure and the large rest capacity of a thick-walled cylinder. [less ▲]

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See detailLe fait du prince étranger
Kinsch, Patrick UL

Doctoral thesis (1994)

Detailed reference viewed: 208 (14 UL)
See detailSequenz und Sequenz-Struktur Vergleiche und deren Anwendung für die Struktur- und Funktionsvorhersage von Proteinen
Schneider, Reinhard UL

Doctoral thesis (1994)

Zusammenfassung der Inaugural-Dissertation Name: Reinhard Schneider Titel: Sequenz und Sequenz-Struktur Vergleiche und deren Anwendung für die Struktur- und Funktionsvorhersage von Proteinen Betreuer ... [more ▼]

Zusammenfassung der Inaugural-Dissertation Name: Reinhard Schneider Titel: Sequenz und Sequenz-Struktur Vergleiche und deren Anwendung für die Struktur- und Funktionsvorhersage von Proteinen Betreuer: Prof. Dr. K. C. Holmes (MPI für medizinische Forschung, Heidelberg) Durch die sogenannten Genomprojekte wird es in den nächsten Jahren zu einer enormen Vergrößerung der biologischen Sequenzdatenbanken kommen. Eine unabdingbare Voraussetzung zur Nutzung dieses Rohmaterials stellt dabei die Analyse dieser Sequenzdaten mit Hilfe rechnergestützter Methoden dar. Eines der Hauptanwendungsgebiete von Rechnern für die Funktions- und Strukturvorhersage von Proteinen werden dabei selektive Datenbanksuche nach biologisch signifikanten Ähnlichkeiten sein. Zur Signifikanzabschätzung eines Proteinsequenzvergleiches (Alignment) wurde ein empirisch abgeleiteter Homologieschwellenwert definiert. Wichtigstes Merkmal ist dabei eine starke Abhängigkeit von der Länge des betreffenden Alignments. Diese Signifikanzabschätzung ermöglicht sowohl den Ausschluß von nicht verwandten Proteinen, wie auch die Detektion von schwachen Sequenzverwandtschaften. Aufgrund der Allgemeingültigkeit des Homologieschwellenwertes kann er als einfacher und effizienter zusätzlicher Filter für andere Methoden, wie z.B. schnelle Datenbanksuchen, verwendet werden. Es wurde ein neuer Algorithmus für den multiplen Sequenzvergleich entwickelt, der eine relativ geringe rechnerische Komplexität besitzt. Das Hauptmerkmal dieses Algorithmus besteht in der Ableitung von sogenannten positionsabhängigen Konservierungsgewichten, die als zusätzliche Parameter im dynamischen Programmieralgorithmus verwendet werden und zu einer deutlich gesteigerten Sensitivität bei Datenbanksuchen führt. Die programmiertechnische Auslegung des Algorithmus erlaubt die zukünftige Erweiterung auf den Vergleich einer Sequenz gegen ein Sequenzprofil bzw. den Vergleich zweier Sequenzprofile. Um auch zukünftig sensitive Datenbanksuchen in einer vertretbaren Rechenzeit durchführen zu können,, wurde das Programm auf parallele Rechner portiert. Die Ergebnisse zeigen, daß mit den heute verfügbaren massiv parallelen Rechnern ein beinahe interaktives Arbeiten möglich ist. Aufbauend auf dieser Arbeit wird derzeit im Rahmen eines europäischen Projektes die Implementierung der Profilmethoden auf Parallelrechner der neuesten Generation durchgeführt und der Nutzen für das industrielle “Protein design” bestimmt. Mit Hilfe des Homologieschwellenwertes konnte eine Datenbank für homologie-abgeleitete Proteinstrukturen (HSSP) entwickelt werden. Diese Datenbank wird der Öffentlichkeit auf verschiedenen Wegen zugänglich gemacht und hat sich als ein gewisser Standard etabliert. Die Datenbank findet dabei Verwendung im automatisierten dreidimensionalen Modellbau von Proteinstrukturen, sowie als Hilfsmittel und Datengrundlage für ein weitgestecktes Feld von statistischen und anderen theoretischen Arbeiten. Die Verwendung der Datenbank hat einen entscheidenden Beitrag bei der Entwicklung des derzeit besten Programms zur Vorhersage der Sekundärstruktur von Proteinen geleistet. Diese Vorhersagemethode basiert auf einem neuronalen Netzwerk, das die Informationen eines multiplen Sequenzvergleichs ausnutzt. Zur Berechnung der multiplen Sequenzalignments und der dazu notwendigen Datenbanksuche wird das in dieser Arbeit entwickelte Programm verwendet. Die Methode wurde in Form eines Vorhersagedienstes, der über internationale Datenleitungen verfügbar ist, der Öffentlichkeit zugänglich gemacht. Einen neuen Ansatz für die Vorhersage von Proteinstruktur bei fehlender Sequenzverwandtschaft zu einer bereits bekannten Struktur stellt die Methode für das Sequenz-Strukturalignment (“threading”) dar. Dazu wird eine dreidimensionale Struktur in Form von interatomaren Kontakten beschrieben und mit Hilfe von Präferenzparametern die Tauglichkeit einer Sequenz in eine Struktur bewertet. Die Ergebnisse zeigen, daß sowohl eine Verbesserung der abstrahierten Beschreibung für eine dreidimensionale Proteinstruktur, wie auch ein verbesserter Alignmentalgorithmus notwendig ist. Ein in der Praxis vielversprechender Ansatz ist die Verwendung von Methoden, die einerseits eine abstrahierte 3D-Beschreibung zulassen und zusätzlich einen gewissen Grad an Sequenzinformation, etwa in Form eines Sequenzprofils mit einbeziehen. Am Beispiel eines kompletten Chromosoms aus Hefe wurde eine komplexe funktionelle Genomanalyse durchgeführt. Hierbei konnten eine Reihe von biologisch interessanten Sequenzverwandtschaften aufgedeckt werden, waren jedoch mit einem hohen Arbeitsaufwand verbunden. Dabei stellte sich die ungenügende Integration der vorhanden Methoden und heterogenen Datenbanken als Hauptproblem heraus. Die dabei gesammelten Erfahrungen fließen derzeit in die Entwicklung eines integrierten Softwarepackets ein, mit dessen Hilfe es möglich sein wird, den Arbeitsaufwand, der zur Analyse von großen Datenmengen notwendig ist, drastisch zu reduzieren. [less ▲]

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See detailModelle der dreimodalen Faktorenanalyse
Krolak-Schwerdt, Sabine UL

Doctoral thesis (1991)

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See detailEvaluations distributionnelles sur une échelle de préférence qualitative
Bisdorff, Raymond UL

Doctoral thesis (1981)

In a first Chapter, we present a critical review of the weighted average when facing distributional performance evaluations measured on an essentially qualitative preference scale. In a second Chapter we ... [more ▼]

In a first Chapter, we present a critical review of the weighted average when facing distributional performance evaluations measured on an essentially qualitative preference scale. In a second Chapter we develop a general typology of qualitative preference scales between between ordinal and cardinal; from non gradual, non metrifyable, partially gradual, gradual, metrifyable, metric extensive to additive, additive-archemidian and measurable scales. The typology is based on the subjective degree of indeterminateness of the numerical representation of the performance contrasts. In a third Chapter we finally define a typology of subjective outranking situations: elementary, intensive or extensive; based on the corresponding underlying type of the preference measurement scale. [less ▲]

Detailed reference viewed: 86 (2 UL)
See detailData Integration for Image Guided Deep Brain Stimulation
Husch, Andreas UL

Doctoral thesis (n.d.)

Detailed reference viewed: 176 (30 UL)