This doctoral thesis is focused into the area of multicarrier radio communications systems. These systems are perspective for current and incoming mobile communications and wireless networks. Advantages of multicarrier systems like better multipath propagation resistivity are redeemed by some disadvantages. The high peak to average power ratio of transmitted signal belongs to these disadvantages, for its inconvenience for high efficient power amplification. The thesis concerns with peak to average power ratio reduction methods for OFDM systems, that belongs to the most used multicarrier systems. One of the main objectives is the modification of the existing methods with the intention of complexity reduction. Following subject of interest is the analysis of suitable methods combinations possibilities for more significant peak to average power ratio reduction. One part of this thesis is research of influence of these methods on the OFDM signals with different parameters.

The presented dissertation thesis deals with a novel structure of delta-sigma () modulator which compensates influence of higher harmonic distortion and therefore it is possible to achieve high resolution up to 16 bits. This novel proposed structure combines advantages of one bit quantizer modulators with mutli-bit modulators. The novel second order structure is presented, correct function is verified in MATLAB simulation enviroment and requirements for partial block are studied. The second part of the work deals with design of converter with novel structure of modulator using switched capacitor technique utilizing ONSemi I3T25 technology. Advantages and disadvantages of the novel structure are evaluated and novel structure is compared with common structures of modulators.

This master thesis deals with design of a subsonic intake which is used to supply small jet engine integrate into the fuselage of agile small unmanned aerial vehicle (UAV). Some kinds of these intakes are listed in order to inspire and introduce future designers into this part of jet plane design. This thesis contains a small amount of theory about compressible flow, and necessary knowledge which are important to know before the very first attempt to design an intake. Two models were designed in order to prove that the theory listed in this thesis is useful and can be used as a guide in design process of subsonic intakes. Both designs have the same layout. S-duct design with one intake placed on the belly of fuselage was chosen. After CFD analysis of first model it was found that there are huge area with separated flow and vortex. Separated flow leads to big total pressure loss and pressure distortion. While designing the second model the emphasis was to avoid this vortex and improve flow conditions. This optimization was success and the second design have smaller pressure loss in compare to the first design. The difference is more than 50% at fly speed M=0,8.

In dieser Arbeit wird die Berechenbarkeit des Deformationsverhaltens von Aluminiumaußenhautbauteilen in einem für die Automobilindustrie typischen Lacktrocknungsprozess um den irreversiblen Kriecheffekt erweitert. Untersucht wird dabei die in Europa oft für Außenhautbauteile eingesetzte Legierung AA6016 mit Hilfe von Zug- und Biegetests, aus denen ein geeignetes Werkstoffmodell für die numerische Simulation abgeleitet wird. Dabei wird auch der Einfluss des Umformgrades im Blechbauteil aus dem Herstellprozess untersucht und bewertet. Die seriennahe Validierung des Werkstoffmodells findet anhand einer eigens ausgelegten Baugruppe statt, die nach dem Wärmeprozess optisch sichtbare Formabweichungen aufweist. Mittels optischer Messungen wird die Baugruppe dabei vor, im und nach dem Wärmeprozess analysiert und die berechneten Formänderungen validiert. Im Ergebnis kann mit dem Werkstoffmodell die Auswirkung thermisch induzierter Spannungen unterhalb der klassischen Streckgrenze auf die Formänderung von Aluminiumblech in der frühen Produktentwicklungsphase prognostiziert werden. / In this work, the computability of the deformation behaviour of aluminium car body panels in a typical automotive paint drying process is enhanced by the irreversible creep effect. The alloy AA6016, which is often used in Europe for aluminium car body panels, is examined with the aid of tensile and bending tests from which a suitable material model for numerical simulation is derived. The influence of the plastic deformation in the sheet metal component due to the manufacturing process is also examined and evaluated. The near-series validation of the material model takes place on the basis of a specially designed assembly which shows optically visible shape deviations after the heating process. Using optical measurements, the assembly is analyzed before, during and after the heating process and the calculated shape changes are validated. As a result, the material model can be used to predict the effect of thermally induced stresses below the classic yield strength on the deformation of aluminium sheet in the early product development phase.

Das zunehmende Aussterben des VHS- und SVHS-Systems sowie weiterer magnetbandbasierter Videosysteme zwingt lokale sächsische Fernsehsender zu einer raschen Digitalisierung großer Mengen analoger Videobänder. Die darauf befindlichen Aufnahmen stellen wichtige Zeitzeugnisse aus der Wendezeit dar und dokumentieren die Herausforderungen, welchen sich die ostdeutschen Bürger nach dem Wechsel von einem sozialistischen zu einem marktwirtschaftlichen System gegenüber sahen. Oftmals ist diese Massendigitalisierung nur von einer generellen Sicherung ohne optimierende Maßnahmen geprägt, sodass qualitative Mängel erst nach der Digitalisierung aufwändig manuell retuschiert werden können. Hierzu ist zunächst ein Überblick über qualitativ gute und schlechte Sequenzen wünschenswert. Bislang existieren jedoch keine Verfahren für eine automatisierte Qualitätsanalyse von Digitalisaten analoger Archivbestände. An dieser Stelle setzt der in der vorliegenden Arbeit vorgestellte Ansatz für eine automatisierte Erkennung und Klassifikation von Störerscheinungen an. Anhand einer extensiven Literaturrecherche und Materialanalyse werden mögliche Störquellen und Störerscheinungen theoretisch identifiziert und systematisiert. Dabei wird die vage, t.w. überlappende und z.T. auch widersprüchliche Terminologie von über 800 Begrifflichkeiten eingeordnet und neu definiert. Die Erkenntnisse werden durch Tabellen und Abbildungen ergänzt, sodass eine bisher nicht existente Übersicht über die diskutierten Phänomene präsentiert werden kann. Zudem wird ein Vorschlag für ein geeignetes Verfahren für deren automatisierte Detektion und Darstellung evaluiert. Die vorgestellte Methode wird mit Hilfe der im Deep Learning üblichen CNN umgesetzt und beinhaltet die Generierung von Datensätzen, das Training des Systems sowie die Klassifikation der zuvor systematisierten Phänomene. Zusätzlich wird eine nutzerfreundliche Darstellung präsentiert, welche es erlaubt, brauchbares und unbrauchbares Videomaterial ohne vertiefte Kenntnisse über Störerscheinungen oder Künstliche Neuronale Netze und ohne Zeitaufwand auf einen Blick zu unterscheiden und semantische Strukturen zu erkennen. Die vorgestellte Methode arbeitet ressourcenschonend und stellt eine Zeit-, Personal- und Kostenersparnis für den Anwender dar. Darüber hinaus lässt sich die Methode auf andere Videoformate adaptieren und auf große Datenbestände erweitern. / Due to the imminent disappearance of magnetic tape-based video systems like VHS and SVHS, local Saxon television stations are forced to digitize large amounts of analog video tapes. The captured scenes provide an insight into the era of German reunification and they document challenges which East German citizens had to face in the transfer from a centrally-planned economy to a free market system. Often, this mass digitization has the purpose as a general 'backup' without any optimization procedures. Qualitative deficiencies of the material must then be reviewed manually in a time-consuming process after the digitization. An overview of high- and low-quality sequences can help to speed up this practice. So far, no methods for an automated quality analysis of digitized archives transferred from analog sources exists.This dissertation presents an approach for classification and automated detection of visual distortions in digitized analog video material. Possible sources of interference and visual distortion were identified and systematized through extensive research of available literature and material analysis. The vague, partially overlapping and even contradictory terminology of over 800 terms was classified and redefined. The findings have then been supplemented by tables and figures to create a new overview of the discussed phenomena, which has not been available beforehand. Furthermore, a proposal for a suitable method for their automated detection and visualization is being evaluated. The presented method was implemented with the help of a deep convolutional neural network and includes the generation of datasets, the training of the system and the classification of the previously systematized phenomena. Additionally, a user-friendly visualization is proposed, which allows to distinguish between useful and unusable video material as well as recognizing semantic structures without an in-depth knowledge of technical or visual disturbances or artificial neural networks. The presented method is resource-efficient and can be adapted to other video formats and expanded to large datasets.

Infant hearing screening (IHS) programs are not yet widespread in developing countries, such as South Africa. In order to ensure that the benefits of early hearing detection and intervention (EHDI) programs reach all infants, initial recommendations for the implementation of IHS programs in South Africa have been made by the Year 2002 Hearing Screening Position Statement by the Health Professions Council of South Africa. One of the platforms recommended for IHS in South Africa is the neonatal intensive care unit (NICU). South African NICU infants are at an increased risk for hearing loss, resultant of their high-risk birth histories, as well as the prevalence of context-specific environmental risk factors for hearing loss. There is currently a general scarcity of contextual data regarding the prevalence of risk indicators for hearing loss, and the prevalence of auditory impairment in the South African NICU population. The objective of this study was to describe an IHS program for NICU infants at a secondary hospital in Gauteng, South Africa. A quantitative descriptive research design was used to report on a cohort of 129 NICU infants followed up during a 29 month period. The objective of the study was achieved by describing the sample of infants in terms of the presence of specific risk indicators for hearing loss, the efficiency of the IHS program, and the incidence of auditory pathologies. Infants received their initial hearing screening as part of their medical and developmental follow-up visit at the hospital at three months of age. Routine rescreening visits were scheduled three monthly, whilst infants who failed the hearing screening were requested to return after three weeks for a follow-up. A data collection sheet was used to collect biographical information and risk indicators for hearing loss. Immittance measurements were recorded in the form of high-frequency and low-frequency tympanometry. Distortion product otoacoustic emissions (DPOAE) and automated auditory brainstem responses (AABR) were recorded, as well as diagnostic auditory brainstem responses (ABR) in cases where infants referred the screening protocol. Results revealed that environmental risk factors present in this sample included poor maternal education levels and prenatal HIV/AIDS exposure. At least 32% of mothers participating in this study did not complete high school. Prenatal HIV/AIDS exposure was present in at least 21% of the current sample of infants. The screening coverage rate fell short of the 95% benchmark set by the Joint Committee on Infant Hearing (JCIH, 2000). A 67% coverage rate was achieved with AABR screening, and an 88% coverage rate was achieved with DPOAE screening. 93% of infants had immittance screening performed on their initial visit to the IHS program. According to the Fisher’s two-sided exact test and the logistic regression procedure, high frequency tympanometry proved to be more effective than low frequency tympanometry, when assessing the middle ear functioning of infants younger than seven months when compared with DPOAE results. Normative pressure and admittance data was compiled for the use of high frequency tympanometry in NICU infants. Poor follow-up rates were recorded for both routine and non-routine visits, but are expected to improve over time. Furthermore, results indicated a high incidence of hearing impairment. Permanent congenital hearing loss was identified in 3% (n=4) of the sample. Half of these presented with sensorineural hearing loss, whilst the other half had auditory neuropathy. The incidence of auditory impairment is estimated to be 3.75% if the percentage of infants who did not return for follow-up is taken into account. A high incidence of middle ear pathology was recorded, with an incidence rate of 60.4%, including bilateral and unilateral middle ear pathology. The high prevalence of auditory impairment in South African NICU infants, and the lack of widespread IHS programs, indicates that many vulnerable infants are being the denied the benefits of early identification of and intervention for hearing loss. The implementation of widespread IHS programs in South Africa is therefore essential, in order to ensure that all South African infants receive the benefits of EHDI programs. / Dissertation (MCommunication Pathology)--University of Pretoria, 2007. / Speech-Language Pathology and Audiology / unrestricted

Den surrealistiska thrillern I´m thinking of ending things av Charlie Kaufman hade premiär på Netflix hösten 2020. Långfilmens narrativ är en utspelad fantasi och innehåller flera inslag som framställs och kan betraktas som verklighetsfrånvända. Syftet med uppsatsen var att undersöka hur overkligheten framställs genom filmklippning och hur kamerapositionering används för att skapa ett fantasi-perspektiv. Klipp-metoder diskuterade av bland annat Bordwell och Thompson, Karen Pearlman och Walter Murch ligger till grund för en audiovisuell analys. Resultatet visar att några av valda sekvenser bryter mot konventionella klippmetoder för att generera konflikt i betraktarens förväntningar. Temporala förvrängningar används för att skapa illusion och fungerar även väl för att skildra fantasi/dröm. / I´m thinking of ending things by Charlie Kaufman premiered on Netflix in the fall of 2020. The featurefilm is a surrealistic thriller who´s narrative is played out like a fantasy containing several elements deviating from reality. The purpose of the essay was to investigate how unreality is portrayled trough the film editing and how camera work is used to create a fantasy perspective. Editing methods discussed by Bordwell and Thompson, Karen Pearlman and Walter Murch, among others, form the basis for an audiovisual analysis. The result shows that several of the selected sequences violate conventional editing to generate conflict of expectations. The use of temporal distortions works as a tool for illusion and to portray dream/fantasy.

À partir d’un corpus ouvert de photographes et de cinéastes coloristes qui ont une fascination pour le nocturne, cette thèse explore les différentes gradations et significations de celui-ci, des plus évidentes aux plus abstraites. La thèse s’attache alors à démontrer que le régime nocturne transforme l’obscurité en valeurs chromatiques et qu’il éclaire, avec une subtilité qu’occulte la vision diurne, les aspects les plus complexes de la société et de l’esprit humain. La confrontation des analyses de séquences filmiques et de photographies dans une perspective articulant esthétique, philosophie et histoire de l’art, a permis de construire la thèse autour de trois grandes notions, Distorsion, Sublimation, Transfiguration, qui fondent le nocturne comme catégorie esthétique de l’image.Le corpus principal organisé sur des critères externes (nocturne, couleur post-années 1960-70) et internes (processus esthétiques conjoints) est composé de séquences de films en couleurs de Stanley Kubrick (1928-1999), de David Lynch (1946), de Brian de Palma (1940), de Francis Ford Coppola (1939) et de séries photographiques de Gregory Crewdson (1962), Bill Henson (1955), Rut Blees Luxemburg (1967) et Daniel Boudinet (1945-1990).Le corpus secondaire est constitué de séries photographiques de Darren Almond (1971), Jean-Christian Bourcart (1960), Nicolas Dhervillers (1981), Laurent Hopp (1974), Chrystel Lebas (1966), d’extraits d’un court métrage d’Antoine Barraud (1973) et d’une série TV de Nic Pizzolatto (1975) et Justin Lin (1973), nécessaire pour finaliser la démonstration. / Based on a large corpus of colorist film directors and photographers who share a fascination for the nocturne, this thesis explores the different gradations and meanings of this one, from the more obvious to the more abstracts. The thesis endeavours to demonstrate how the nocturne reasserts the darkness values to turn them into colors, and how it illuminates, with a subtlety absent in diurnal vision, the more complex aspects of society as well as the human mind.The confrontation between picture and film sequences analysis, with a perspective articulating aesthetic, philosophy and art history, leads to three main concepts: Distortion, Sublimation and Transfiguration. Thereby it establishes the nocturne as an image’s aesthetic category in cinema and photography.The main corpus in cinema and photography, organised by externals criteria (nocturne, post-1960-1970 years color) and internals criteria (similar operating processes aesthetic), is established with the movie extracts of Stanley Kubrick (1928-1999), David Lynch (1946), Brian de Palma (1940), Francis Ford Coppola (1939) as well as the photographic series of Gregory Crewdson (1962), Bill Henson (1955), Rut Blees Luxemburg (1967) and Daniel Boudinet (1945-1990).The second is based on the photographic series of Darren Almond (1971), Jean-Christian Bourcart (1960), Nicolas Dhervillers (1981), Laurent Hopp (1974) and Chrystel Lebas (1966), as well as Antoine Barraud’s (1973) movie extracts. Finally, for the requirement of the demonstration, a Nic Pizzolatto (1975) and Justin Lin (1973) TV show.

The master thesis is focused on current issues of concrete behaviour under high temperatures. In the theoretical part, a search of knowledge about changes in concrete, which take place when exposed to thermal loads, which simulates the effect of fire, is performed, and summarized. It is also important to summarize the changes in the individual components that are used to produce concrete. This work describes the effect of high temperatures on mechanical and physical properties as well. There is an information about the most used fibres and their function in concrete. Emphasis is placed on describing the possibility of using recycled PET or cellulose fibres due to the positive environmental impact. In the experimental part, recipes with different types and amounts of fibres are proposed. The subject of the research was to determine how individual types and amounts of fibres affect the physical mechanical properties of concrete and their suitability for use at high temperatures. Microscopic scanning and study of changes in the structure of concrete was also performed.

No description available.