Böcker utgivna av Cuvillier

Non-proteinogenic amino acids are often important constituents of biologically potent natural products. The synthesis of these amino acids is often time-consuming, non-trivial and not sustainable. Thus, the central topic of this work was the formation of unusual amino acid structures by biocatalytic and catalytic methods. For the elucidation of the biosynthetic pathway of Streptomyces-produced muraymycins and related natural products, a ¿biosynthetic tool kit¿ was compiled and prepared. This does not only comprehend the completed synthesis of deuterium-labeled compounds, such as (3R)- and (3S)-3-hydroxy-[5-2H]-l-arginine and other potential intermediates with a nucleosidic structure, but it also includes the development of fermentation methodology including the possibility to detect the muraymycin derivatives by LC MS. Furthermore, different synthetic routes with catalytic key steps for the preparation of the non-proteinogenic amino acid enduracididine were investigated.

On 14 December 2010 the European Commission presented its Proposal to amend the most important instrument on European international civil procedure, the Regulation 44/2001 (¿Brussels I`). Against the background that European law guarantees economic freedoms cross-border recognition and enforcement of judgments within the European Union is of considerable and increasing importance. Brussels I provides for a simple and accelerated procedure to obtain the required declaration of enforceability (the exequatur) in the Member State of enforcement. In order to further enhance the free movement of judgments within the EU the general abolishment of this exequatur lies at the heart of the Proposal. It is accompanied by plans to reform the existing defences.This dissertation provides an analysis and discusses the most relevant aspects of the abolishment of the exequatur and the reform of the defences under the Proposal. After providing the background on the Proposal and its underlying principles, the cross-border enforcement regimes of Brussels I and the Commisson`s Proposal are briefly presented. The abolishment of the exequatur is critically discussed with regard to its underlying rationales and the functions of the exequatur. The chapter concludes with the implications of the abolishment for the existing defences. The reform of the defences is discussed in debt in the third chapter with regard to the questions whether the Proposal provides sufficient protection and complies with the principle of mutual recognition. Particular emphasis is put on the ordre public defence and its fundamental rights implications. Suggestions to amend the Commission`s Proposal are made throughout the paper and briefly summarised in the final conclusion.

Sloshing of cryogenic liquid propellants in launch vehicle tanks creates unwanted thermodynamic side-effects such as pressure changes in the tank.The goal of this PhD research was to develop a practical engineering model which is able to describe the influence of the sloshing of a cryogenic liquid on the heat and mass transfer and the associated temperature and pressure.The pressure changes caused by sloshing were investigated experimentally and numerically. Using the experimental and numerical results, a one dimensional (1D) engineering model was developed which is able to describe the experimental results.

Nowadays we are living in an era that is overloaded with information. Decision-making in this environment can sometimes become a nightmare. There are too many choices and we simply cannot explore them all. Therefore, it would be really helpful to have a system to help us to find the right choice. Such systems, which learn user preferences and provide personalized recommendations to them are called Recommender Systems.Evidently, the performance of recommender systems depends on the amount of information that users provide regarding items, most often in the form of ratings. This problem is amplified for new users because they have not provided any rating, which impacts negatively on the quality of generated recommendations. This problem is called new user problem or cold-start problem. A simple and effective way to overcome this problem, is by posing queries to new users so that they express their preferences about selected items, e.g. by rating them. Nevertheless, the selection of items must take into consideration that users are not willing to answer a lot of such queries. To address this problem, active learning methods have been proposed to acquire the most informative ratings, i.e ratings from users that will help most in determining their interests.The aim of this thesis is to take inspiration from the literature of active learning for machine learning and develop new methods for the new user problem in recommender systems. In the recommender system context, new users play the role of the Oracle and provide labels (ratings) to the queries (items). In this approach, we will take into consideration that although there are no data for new users, but there is abundant data for existing users. Such additional data can help us to develop scalable and accurate active learning methods for the new user problem in recommender systems.The thesis consists of two parts. In the first part, to be consistent with the settings of active learning in machine learning and the related works on the new user problem in recommender system, it is assumed that the new user is always able to rate the queried items. Next, this constraint is relaxed and new users are allowed not to rate the items.Most of the developed active learning methods exploit the characteristics matrix factorization because nevertheless, recent research (especially as has been demonstrated during the Netflix challenge) indicates that matrix factorization is a superior prediction model for recommender systems compared to other approaches.

La Meteorología se ha convertido en los últimos años en una de las más importantes disciplinas en el mundo actual que junto con la Climatología nos describen los fenómenos físicos desarrollados en la atmósfera, complementándose con el análisis para enfocar los efectos hacia los seres vivos y de manera particular a los humanos, ecosistemas. Las dos disciplinas han tomado la posición que desde siglos ya les pertenecía, todo esto gracias al flujo de información mundial y antes de nada por el manejo de datos de los elementos meteorológicos y climáticos por la comunidad científica mundial apoyándose en la bondad de las súper computadoras que pueden analizar millones de datos en los modelos desarrollados para de esta manera predecir futuros acontecimientos en tiempos muy cortos.El libro contiene 13 capítulos. Los cuatro primeros capítulos se relacionan con principios básicos de la atmósfera. Desde el capítulo 5 hasta el 7 se hace una recopilación de las fuerzas mecánicas que actúan sobre la Tierra. Los capítulos 8 y 9 corresponden a la Radiación proveniente del Sol que maneja la mayor parte de la energía del planeta. El capítulo 10 se ocupa de la descripción de la Termodinámica aplicada a los procesos en la atmósfera. Los movimientos del aire están especificados en los capítulos 11, 12 y 13. Se hace un pequeño resumen acerca de los principios de la Climatología.

In the present work, urgent issues in the reliability qualification of semiconductor devices are addressed, which particularly affect value chains such as those in the automotive industry. These have particularly high requirements for long lifetime and low failure rates of their products, which are additionally exposed to more extreme operating and environmental conditions than in most other areas of application. In particular, the question arises on how to assess a product or semiconductor technology against the requirement of an application-specific mission profile with multiple non-constant stressors.For this purpose, the behavior of failure distributions under varying and progressive stress loads is investigated and described using cumulative damage models. For the first time, the industry-wide approach of transforming non-constant mission profiles into effective constant stress and test conditions for reliability assessment and qualification can be physically justified and substantiated with measurement data. This stress transformation is exemplified using the time-dependent dielectric breakdown (TDDB) failure mechanism with the two stressors voltage and temperature; and then extended to include the use of multi-dimensional mission profiles and interdependent stressors. These measurements are performed on university metal-oxide-semiconductor (MOS) capacitors as well as on commercially available state-of-the-art transistors. Finally, it is demonstrated that the obtained findings in the field of cumulative damage can be applied to use reliability studies with ramp-stress for acceleration model verification and to determine model parameters with less time and experimental effort.

Die Dissertation beschreibt die Synthese und Charakterisierung verschiedener Münzmetallkomplexe an einem strukturgebenden tetradentaten monoanionischen PNNP Liganden. Von Interesse war die Frage nach einer möglichen Korrelation der lumineszenten Eigenschaften mit ausgewählten strukturellen Parametern. Es wurden daher selektiv Komplexe mit verschiedenen Kombinationen aus Art und Anzahl an Metallatomen innerhalb des Ligandensystems realisiert. Nach der Vorstellung von homometallischen zwei- und dreikernigen Komplexen, konnten, ausgehend von der zweikernigen Goldverbindung, verschiedene vierkernige und ein sechskerniger Goldkomplex synthetisiert werden. Die Verbindungen wurden intensiv bezüglich ihrer lumineszenten Eigenschaften, einige davon in verschiedenen Phasen, und zudem teilweise theoretisch untersucht.Aufbauend darauf gelang die Darstellung mehrerer Lanthanoid-Münzmetallkomplexe, die ebenfalls bezüglich ihrer lumineszenten Eigenschaften analysiert wurden.Außerdem wurden in einem kleinen Teil der Arbeit Münzmetallkomplexe mit einem Ferrocenylbisamidinatliganden vorgestellt, die teilweise eine kurze Fe M Distanz aufweisen

The automotive industry is pushing towards highly assisted and even autonomous driving cars. To gather a more precise and reliable representation of the car¿s surroundings, the sensors and the signal processing are improving over time and are a subject to continuous research. One essential sensor is the radar, which is robust and reliable even in harsh environmental conditions. The primary downside of a radar is its low resolution compared to lidar or camera-based systems.To mitigate these drawbacks the resolution of radar systems has to be improved. The bandwidth has to be increased to improve the range resolution, and the aperture has to be increased to improve the angular resolution.Primarily caused by the automotive industry, fully integrated radar on chip solutions are now available and allow the construction of more complex radar systems. These radar on chip devices lay the foundation for radars that fulfill the requirements of increased resolution for future systems.Although this work is focused automotive applications, most ideas, concepts, and calculations are also applicable to other fields. Similar systems may be used in the security sector, quality control in industrial processes, or gesture detection, to name a few examples.This thesis shows the development of a conceptual future radar system for automotive applications. The focus is on providing a large antenna aperture to achieve the required high angular resolution. Two genetic algorithms are developed to optimize the antenna array for a good side lobe level while providing high angular resolution.Two demonstrators are built to implement certain aspects of the proposed radar system and prove the general concept viable. The first demonstrator features a large aperture with a limited side lobe level and is using a modular approach. The modules are synchronized with a radio over fiber system. The second demonstrator uses the previously proposed antenna array, which is implemented with a synthetic aperture radar approach. The system¿s capabilities in a real scenario are demonstrated, and the reconstruction of a high-resolution three-dimensional image from the captured data is shown.As larger arrays for radar systems automatically come with higher manufacturing tolerances, larger thermal expansion, and other negative impacts on the actual antenna positions, this work also analyzes the impact of such imperfections. Additionally, an algorithm is proposed, which can estimate the actual antenna displacement during operation. Therefore, the system is capable of compensating for most of the negative effects.

In 1959 Anderson et. al publish their paper ¿The CAA Doppler Omnirange¿. In that contribution they present their analytically derived receiver¿model for quantifying the bearing error of the Doppler VOR (DVOR) due to multipath propagation. At that time this model exclusively serves for comparing the susceptibility of the DVOR with the one of its precursor which is the conventional VOR. For this purpose, they take the impact of a static omnidirectional scatterer solely upon one signal component into account, which is the frequency modulated one.Due to the number of already installed wind turbines and especially due to the desire to install way more turbines, the signal integrity of the DVOR has become a very timely topic in Germany in the context of renewables energies.In this dissertation Anderson¿s basic generic model is both improved and substantially extended with respect to the impact of wind turbines upon the multipath signal.In the first part of this work Anderson¿s error model is quantitively expended with respect to the relative amplitude of the scattering path. Furthermore, the analytical model is fundamentally improved with respect to quality: For the first time the analytical model allows to take the dynamic effects of wind turbines into account, i.e. both Doppler shifts as well as an additional amplitude modulation due to the scattering object ¿ namely the wind turbine. Additionally, this analysis is carried out for the DVOR¿s reference provided by an amplitude modulated signal component, which has been completely neglected so far by the current state of the art.These analytical models allow for extensive parameter studies, which are applicable e.g. for the validation of both numerical simulation tools as well as approaches by measurements.In the second part of this work the dynamic impact of wind turbines upon the DVOR¿s bearing intelligence is investigated by measurements. This is carried out in an environment scaled with a ratio of 1:144. It utilizes the equipment realized within the projects ¿Sk-ILS¿ and ¿min-Vor-Win¿ and expands it by inventing a procedure for crafting and electromagnetically characterizing voluminous scattering bodies. These allow for a systematic analysis of the impact of terrain topologies.A variety of measurements and the corresponding fundamental analysis address: Doppler shifts and Doppler spectra depending on the orientation of the plane of rotation, the blades¿ shape, revolutions per minute, and the position of the turbines as well as the amplitude and width of Doppler spectra.Fundamental results of this work are e.g.: A 10 km safety¿radius of the DVOR¿s protective area, up to now applied in Germany and as well recommended by the ICAO, can be considered way to restrictive. Furthermore, the receiver settings play a crucial role, when determining the bearing error. Thus, stating the latter makes it mandatory to state the receiver settings as well.

Particularly in the upper stage development of rockets (launchers), gravity dominated fluid motion in upper stage tanks (sloshing) during flight represents an undesired dynamic effect. On the one hand the sloshing forces lead to disturbances, which have to be compensated by the reaction control system. On the other hand, when cryogenic fluids are considered, the fluctuations in tank pressure may be critical under some circumstances compromising the structural stability of the tank. In this field, the utilization of cryogenic propellants represents a high challenge to layout and design of the propulsion components including the propellant tanks.This work deals with two effects that are directly coupled to the sloshing content inside the propellant tank. To investigate these effects a dedicated test setup has been developed. At first, the damping characteristics of sloshing cryogenic nitrogen ¿ which is used as a substitute for the rocket propellants liquid hydrogen and liquid oxygen ¿ are determined. The results are correlated to the theory based on storable propellants. The main part of this work is linked to a characteristic pressure drop inside the propellant tank caused by the sloshing liquid. For the effect to occur, the tank must be pressurized to enable the formation of a thermal stratification below the liquid surface. Sloshing leads to the mixing of liquid in this region with subcooled liquid from the bulk. This affects the decrease of the temperature at the free surface leading to the condensation of superheated vapor. Thus, the pressure in the tank must decreases. Three different pressurization concepts are introduced in this work; self-pressurization where the tank is pressurized by evaporating liquid caused by the heat flowing into the tank. Furthermore, the tank is pressurized with gaseous nitrogen taken from an external gas bottle and at last gaseous helium from an external supply is used for pressurization purpose. By the application of helium as non-condensable gas, a significant reduction of the pressure drop is expected. The experimental results confirm this working hypothesis and therefore support the theoretical considerations described by an approach of Das & Hopfinger.All results are presented in a non-dimensional form to allow the comparison to data from the literature. Furthermore, the upscaling of the current results enables the prediction for future cryogenic upper stages such as the ESC-B for the European space launcher Ariane 5.

A song was presented in the Kaweinag-Asmat language by people living in the south of the Asmat region in Papua in 1984. It conveyed parts of the story of Saunat, one of their mythical heroes. Several years later, a recording of this song served as the source for a research project.A presupposition for this project was the translation of the song-text. In 2007, the place where the recording was made was the locality for the attempt to translate the text. Elaborating a transcription and translating this transcript proved to be far more of a challenge than expected. The difficulties of this work and the uncertainties its results contain will not be concealed. On the contrary, they will become evident in the documentation of this scientific project.The elaborated transcription and translation versions of the song are reproduced in this book.The stories of Saunat belong to the wonderful testimonies of Asmat mythology. They illustrate a socially animating and innovating concept of surmounting dividing lines.