TY - THES A1 - Herder, Jens T1 - A Sound Spatialization Resource Management Framework N2 - In a virtual reality environment, users are immersed in a scene with objects which might produce sound. The responsibility of a VR environment is to present these objects, but a practical system has only limited resources, including spatialization channels (mixels), MIDI/audio channels, and processing power. A sound spatialization resource manager, introduced in this thesis, controls sound resources and optimizes fidelity (presence) under given conditions, using a priority scheme based on psychoacoustics. Objects which are spatially close together can be coalesced by a novel clustering algorithm, which considers listener localization errors. Application programmers and VR scene designers are freed from the burden of assigning mixels and predicting sound source locations. The framework includes an abstract interface for sound spatialization backends, an API for the VR environments, and multimedia authoring tools. KW - audio rendering KW - human perception KW - Resource Management KW - Sound Spatialization Y1 - 1999 UR - http://vsvr.medien.hs-duesseldorf.de/publications/phd99-abstract.html PB - University of Tsukuba CY - Tsukuba ER - TY - THES A1 - Deckert, Carsten T1 - Wissensorientiertes Projektmanagement in der Produktentwicklung BT - Zugl.: Aachen, Techn. Hochsch., Diss., 2002. Y1 - 2002 PB - Shaker Verlag CY - Herzogenrath ER - TY - THES A1 - Neef, Matthias T1 - Analyse des Schlagfluges durch numerische Strömungsberechnung N2 - Mit Hilfe eines Finite-Volumen-Verfahrens wird die dreidimensionale reibungsbehaftete Stroemung um einen schlagenden Fluegel berechnet. Die Bewegungsparamter sind dabei vergleichbar mit den Bedingungen im Reiseflug grosser Voegel. Das numerische Verfahren wird fuer den gezeigten Anwendungsfall, indem eine Methode zur Realisierung von beliebigen periodischen Bewegungen implemetiert wird. Eine Verifizierung erfolgt durch den Vergleich mit analytischen, numerischen und experimentellen Ergebnissen aus der Literatur. Mit dem verifizierten Verfahren werden die instationaeren Groessen wie Druck und Geschwindigkeiten in der Umgebung des bewegten Fluegels berechnet. Daraus ergeben sich ferner die zeitlich gemittelten Groessen wie Schub und Wirkungsgrad des Schlagfluges. Ausserdem wird die Interaktion von Laengs- und Querwirbeln im Nachlauf des schlagenden Fluegels untersucht. Es zeigt sich ein dominanter Einfluss der pulsierenden Randwirbel aufgrund der endlichen Spannweite, waehrend die Anfahr- und Stoppwirbel, verursacht durch die Fluegelbewegung, im Reiseflug grosser Voegel nahezu vernachlaessigbar erscheinen. N2 - The three-dimensional viscous flow around a flapping wing is calculated by means of a finite volume code. The invoked motion parameters are comparable with the conditions in cruising flight of large birds. For the described application the numerical procedure is extended by implementing a method for realisation of arbitrary periodic motions. The verification is obtained by comparison with analytical, numerical and experimental results from existing literature. With the verified method the instationary quantities such as pressure and velocity are known in the vicinity of the wing. This also yields the time averaged values such as thrust and propulsive efficiency of the flapping wing propulsion. Additionally, the interaction between longitudinal and transverse vortices in the wake of the flapping wing is investigated. A dominant influence of the oscillating tip vortices due to the finite span can be seen, while the starting and stopping vortices due to the wing motion appear almost negligible in the cruising flight of large birds. Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:084-14501 UR - http://www.digibib.tu-bs.de/?docid=00001361 VL - ZLR-Forschungsbericht, 2 ER - TY - THES A1 - Braun, Alexander T1 - Addressing Single Yb+ Ions: A new scheme for quantum computing in linear ion traps Y1 - 2007 SN - 978-3-86727-276-6 PB - Cuvillier Verlag CY - Göttingen ER - TY - THES A1 - Richter, Nicole T1 - Interne Kommunikation im Krisenmanagement Y1 - 2007 SN - 978-3-89936-584-9 VL - Personal, Organisation und Arbeitsbeziehungen, 43 PB - Lohmar CY - Köln ER - TY - THES A1 - Grote, Wolfgang T1 - Ein Beitrag zur modellbasierten Regelung von Entnahmedampfturbinen KW - Dynamische Modellierung KW - Dampfturbine KW - Prädiktive Regelung KW - Dampfkraftwerk Y1 - 2009 UR - https://hss-opus.ub.ruhr-uni-bochum.de/opus4/2109 PB - Bochum ER - TY - THES A1 - Franz, Thomas T1 - Semantic Personal Information Management BT - Zugl.: Koblenz, Univ., Diss., 2010 Y1 - 2010 SN - 978-3-86853-706-2 PB - Universität Koblenz-Landau CY - München ER - TY - THES A1 - Stuhlsatz, André T1 - Machine learning with Lipschitz classifiers N2 - complex image, like for example that of a known person, and to distinguish it from other objects within half a second. While for a solution of this task the brain has access to a massive parallelism and a vast, hierarchically organized, and auto-associative memory, common computer architectures are just able to a sequential processing of information stored in a non auto-associative memory. Even modern, parallelly operating, multi-processor systems are far away from the performance of our brain. However, nowadays, it is possible to solve complex and memory extensive pattern recognition problems, like the recognition of handwritten digits or the transcription of speech, satisfactorily with a common computer by the use of modern statistical and algorithmic learning approaches. One of the most successful pattern recognition methods is the so-called Support Vector Machine (SVM). The SVM is based on the learning paradigm of structural risk minimization, which outperforms empirical approaches if only few data is available for solving the considered classification problem. Although the SVM has proven very good recognition performances in many cases, the SVM also comes up with limitations, for example if specific a priori knowledge shall be used. In particular, the increasing complexity of applications requires a high adaptivity of the classification method to the specific problem. Also concerning this point, the SVM is limited due to a restricted variety of implementable classification functions. The objective of the present thesis is the development of new learning algorithms for the classification of patterns, that on the one hand overcome the limitations of the SVM, but on the other hand are based on the same theoretical concepts facilitating the good performance of the SVM. Two new algorithms will be presented that are justified by a theoretical generalization of the SVM, and which will be utilized for the first time for a practical implementation. In contrast to the SVM, the new methods make accessible a much larger function class for constructing a classifier. This is an important prerequisite for flexible adaptation of the classifier to difficult classification tasks with particular requirements as well as for the integration of a priori knowledge about the problem at hand. In this work, the way to implementable algorithms leads across different mathematical reformulations of the original problem. Starting with the theoretical generalization of the SVM, it results a restricted optimization problem that is difficult to solve in general. In a first step, this problem is expressed in terms of a restricted minimax-problem by a modification of the suitable classification functions to a still very large function class consisting of (affine-)linear combinations of at least one-time continuously differentiable functions. In the next step, the minimax-problem is converted into a so-called Semi-Infinite Problem (SIP). It turns out, that this particular mathematical problem is appropriate in order to obtain a solution of the original problem for the considered function class using well-known optimization methods. To further exploit the problem structure, an equivalent dual problem is derived from the SIP. Therefore, we prove a duality theorem about the equality of the optimal values of the dual and the original problem. For solving the dual problem, a multilevel iterative approach is developed from which the proposed algorithms follow by pursuing different solution strategies. Moreover, all sub-optimization methods of any stage necessary for an implementation in software are developed. Namely, these are an adapted interior-point-method, a simulated annealing based search heuristics and a particular gradient decent approach. Furthermore, options are depicted for an improvement of efficiency for future implementations. Besides the emphasis on the theoretical development of new learning methods and their practical implementations, all algorithms were implemented in the MATLAB(R) programming environment for the experimental part of the present thesis. Hence, they are also available for further research purposes in future. For the first time, classification results are explored and evaluated in comparison to the SVM on different data sets. As test data, an artificial 2d-dataset as well as two real-world datasets were used. In the concluding experiment, a scenario is prototypically considered to which the SVM is only inadequately applicable and which shall precisely prove the capability of the new methods in that case. It follows, regarding the considered datasets, the proposed learning methods reach comparably good classification accuracy like the SVM in standard applications. Moreover, the particular benefit of the new methods is reflected theoretically and experimentally in the ability to solve classification problems using decision functions that are not accessible to SVMs. Thereby, the underlying ideas, which make the SVM excel compared to other approaches with respect to generalization performances in case of few available learning information, are adequately transported into the proposed new environment. This opens the way for a design and a use of new classifiers that have not been implementable in a robust and generalizing basic concept so far. Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:101:1-201104192945 PB - Otto-von-Guericke-Universität Magdeburg CY - Magdeburg ER - TY - THES A1 - Steffens, Jochen T1 - "Wie viel Realität braucht der Mensch?" - Untersuchungen zum Einfluss der Versuchsumgebung auf die Geräuschbeurteilung von Haushaltsgeräten Y1 - 2013 U6 - https://doi.org/10.14279/depositonce-3732 PB - Technische Universität CY - Berlin ER - TY - THES A1 - Eilert, Eva T1 - New applications of heterologous gene expression in Hansenula polymorpha for protein and metabolite production N2 - The methylotrophic yeast Hansenula polymorpha has been established as a highly efficient expression system. Strong promoters derived from the methanol metabolism pathway and mitotically stable high-copy integration have made this organism very effective for heterologous protein expression. To improve the processing of secretory proteins targeted by the MFα prepro sequence, variations in the amino acid composition near the processing site of Kex2p were investigated (Manuscript I). The insertion of Ala-Pro between MFα prepro sequence and protein of interest leads to an improved processing of the signal sequence in case of interleukin-6 (IL-6) and interferon-α 2a (IFNα-2a). Modeling of the transition sequences confirmed a better exposition of the Kex2p-cleavage site in dependency of Ala-Pro insertions. Analysis of the secreted proteins revealed activity of an Ala-Pro specific endoprotease. Partial removal of the N-terminal Ala-Pro dipeptide was also detected during IFNα-2a processing. The putative protease responsible for the processing of Ala-Pro dipeptides was identified by gene deletion. Significant similarities with Saccharomyces cerevisiae Ste13p were identified. To generally improve productivity in the H. polymorpha system new fusion protein strategies were investigated (Manuscript II). The recombinantly strongly expressed cytosolic ferritin heavy chain (FTH1) was analyzed with regard to its potential as fusion partner for difficult-to-express target proteins. A fragment of the parathyroid hormone (PTH) was chosen to explore whether fusion to FTH1 enhances PTH stability. We could show that the expression level of this fusion protein was at least of the magnitude of that of FTH1 without fusion partner. The solubility of the fusion protein was increased in comparison to FTH1 alone and no degradation of PTH occurred when fused C-terminally to FTH1. Ectoine and 5-hydroxyectoine belong to the family of compatible solutes which are known to contribute to the adaptation of the cell to osmotic stress by mediation of a constant turgor. H. polymorpha was engineered to express the enzymes of the H. elongata 5-hydroxyectoine biosynthesis pathway (Manuscript III). Expression of the enzymes EctB, EctA, EctC and EctD in H. polymorpha resulted in production of 5-hydroxyectoine in gram per liter scale with almost full conversion of ectoine to 5-hydroxyectoine. We showed that 5-hydroxyectoine synthesis was influenced by feeding of methanol during cultivation. Furthermore, 5-hydroxyectoine synthesis was downregulated by the addition of methionine, lysine or threonine indicating the existence of a feedback regulated aspartate kinase in H. polymorpha. N2 - Die methylotrophe Hefe Hansenula polymorpha hat sich als effizientes System zur heterologen Genexpression etabliert. Besondere Merkmale dieses Systems sind die starken Promotoren des Methanolstoffwechsels und die Fähigkeit zur mitotisch stabilen Integration einer Expressionskassette in einer hohen Kopienzahl. Am Beispiel der MF α prepro Sequenz sollte die Prozessierung sekretorisch exprimierter Proteine verbessert werden (Manuskript I). Hierfür wurden Veränderungen in der Nähe der Kex2p Erkennungssequenz durchgeführt. Durch das Einfügen von Ala-Pro zwischen MF_ prepro Sequenz und Zielprotein konnte die Prozessierung im Fall von Interleukin-6 (IL-6) und Interferon- α 2a (IFN α -2a) verbessert werden. Eine Modellierung dieses Sequenzübergangs zeigte eine verbesserte Präsentation der Kex2p-Schnittstelle. Nach Analyse des sekretierten IL-6 wurde außerdem die Aktivität einer Ala-Pro spezifischen Endoprotease festgestellt. Auch im Falle von IFN α -2a konnte eine partielle Abspaltung des N-terminalen Ala-Pro-Dipeptids festgestellt werden. Ein Protease, welche mutmaßlich an der Prozessierung dieser Ala-Pro-Dipeptide beteiligt ist, wurde per Gendeletion identifiziert. Diese Protease wies signifikante Ähnlichkeiten mit der S. cerevisiae Ste13p auf. Zur allgemeinen Verbesserung der Ausbeute bei der Produktion heterologer Proteine wurden neue Fusionsprotein-Strategien untersucht (Manuskript II). Hierfür wurde das rekombinant cytosolisch stark exprimierte Protein Ferritin (schwere Kette, FTH1) im Hinblick auf das Potenzial als Fusionspartner für schwierig zu exprimieren Zielproteine analysiert. Ein Fragment des Parathormons (PTH) wurde gewählt, um zu untersuchen, ob die Fusion beider Proteine die Stabilität von PTH erhöht. Wir konnten zeigen, dass die Expression dieses Fusionsproteins mindestens in der Größenordnung des FTH1 ohne Fusionspartner war. Die Löslichkeit des Fusionsproteins wurde gegenüber FTH1 allein erhöht und es trat kein Abbau des PTH in Fusion mit FTH1 auf. Ectoin und 5-Hydroxyectoin gehören zur Familie der kompatiblen Solute, die hauptsächlich zur Anpassung der Zelle bei osmotischem Stress durch Anpassung des Turgors beitragen. Ein H. polymorpha-Stamm wurde entwickelt, welcher die Enzyme der 5-Hydroxyectoin-Biosynthese aus H. elongata exprimiert (Manuskript III). Die Expression der Enzyme EctB, EctA, EctC und EctD in H. polymorpha resultierte in der Produktion von 5-Hydroxyectoin im Gramm pro Liter Bereich. Es fand außerdem eine nahezu vollständige Umwandlung von Ectoin in 5-Hydroxyectoin statt. Wir konnten zeigen, dass die 5-Hydroxyectoin-Synthese durch Zugabe von Methanol während der Kultivierung beeinflusst wurde. Desweiteren wurde die 5-Hydroxyectoin-Synthese durch die Zugabe von Methionin, Lysin oder Threonin herunterreguliert, was andeutet, dass in H. polymorpha eine Feedback-regulierte Aspartatkinase existiert. T2 - Neue Ansätze der heterologen Genexpression in Hansenula polymorpha zur Protein- und Metabolitenproduktion Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:061-20130527-092604-7 PB - Institut für Molekulare Mykologie, Institut für Mikrobiologie CY - Düsseldorf ER -