05 Fakultät Informatik, Elektrotechnik und Informationstechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6
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Item Open Access Prozessbausteine(2014) Eberle, Hanna; Leymann, Frank (Prof. Dr.)Gegenwärtig existierenden Modellierungssprachen und Werkzeugen zur Umsetzung prozessbasierter Anwendungen liegt im Allgemeinen die Annahme eines zur Entwicklungszeit bekannten und in seiner Struktur vollständig ausmodellierten Prozessmodells zugrunde. Für Szenarien, in welchen eine prozessbasierte Anwendung neben stabilen, d.h. zur Modellierungszeit des Prozesses bekannten, auch durch dynamische, d.h. erst zur Anwendungslaufzeit geltende, Rahmenbedingungen beeinflusst wird, ist eine derartige statische Prozessmodellierung nur bedingt geeignet. In diesen Szenarien ist es vielmehr wünschenswert, (i) zur Entwicklungszeit bereits bekannte Prozessteile der Anwendung detailliert ausmodellieren zu können, und diese (ii) zur Laufzeit der Anwendung unter Berücksichtigung der zum Ausführungszeitpunkt geltenden dynamischen Rahmenbedingungen zum vollständigen Prozess der Anwendung zu integrieren. Das im Verlauf dieser Arbeit vorgestellte Konzept der Prozessbausteine setzt an diesem Punkt an und schafft ein Rahmenwerk für die Modellierung und Ausführung prozessbasierter Anwendungen unter Berücksichtigung sowohl stabiler als auch dynamischer Rahmenbedingungen. Kerngedanke des Konzepts ist die Abbildung stabiler Rahmenbedingungen zur Entwicklungszeit in Form teilweise unvollständiger Prozessmodelle, sogenannter Prozessbausteine. Zu einem späteren Zeitpunkt im Lebenszyklus der Anwendung werden diese Prozessbausteine dann, motiviert durch die jeweils geltenden dynamischen Rahmenbedingungen, mit weiteren Prozessbausteinen zum vollständigen Prozessmodell der Anwendung integriert. Zur vollständigen Unterstützung der Entwicklung von Anwendungen auf Grundlage dieses Konzepts umfasst die vorliegende Arbeit die Definition eines Metamodells für sowohl die Modellierung einzelner als auch die Repräsentation integrierter Prozessbausteine, die Beschreibung der Ausführung integrierter Prozessbausteine, sowie die Vorstellung einer Architektur für die Ausführung integrierter Prozessbausteine.Item Open Access Effiziente Synthese konsistenter Graphen und ihre Anwendung in der Lokalisierung akustischer Quellen(2015) Kreißig, Martin; Yang, Bin (Prof. Dr.-Ing.)In dieser Arbeit wird das Problem der simultanen, akustischen Mehrquellenlokalisierung in echobehafteten Umgebungen genauer betrachtet und daran beispielhaft die Anwendungsmöglichkeit der Synthese konsistenter Graphen gezeigt und analysiert. Dafür werden die Grundlagen der akustischen Lokalisierung eingeführt und unterschiedliche Ansätze vorgestellt. Im Besonderen werden die laufzeitdifferenzbasierten Lokalisierungsverfahren betrachtet, die das Problem der uneindeutigen Zuweisung der Laufzeitdifferenzen zu den Quellen haben. Anhand dieses konkreten Anwendungsbeispiels der Lokalisierung wird die Problematik auf ein graphentheoretisches Problem abstrahiert. Deshalb werden zunächst die graphentheoretischen Grundlagen und bereits bekannte Algorithmen, wie die Tiefen- und Breitensuche eingeführt, die beide einen aufspannenden Baum suchen. Der aufspannende Baum ist notwendig, um die Menge der fundamentalen Maschen zu bestimmen. Die Synthese konsistenter Graphen erfolgt durch das Zusammenführen der konsistenten fundamentalen Maschen. Dabei unterscheidet man folgende Vorgehensweisen: die Synthese voll konsistenter Graphen, die jeder Kante des Eingangsgraphen ein konsistentes Kantengewicht zuweisen und die Synthese partiell konsistenter Graphen, die nur eine Teilmenge von Kanten beinhalten. Beide Vorgehensweisen basieren auf den konsistenten fundamentalen Maschen, welche die Nullsummenbedingung erfüllen. Die Synthese voll konsistenter Graphen wird über ein Backtracking-Verfahren realisiert. Die Synthese partiell konsistenter Graphen wird aus dem Kompatibilitäts-Konflikt-Graph abgeleitet, der ein neuer Typus von Graph ist und die drei unterschiedlichen Zustände zwischen den konsistenten fundamentalen Maschen beschreibt: 1) zwei konsistente Maschen haben keine gemeinsame Kanten, 2) zwei konsistente Maschen haben gemeinsame Kanten und identische Kantengewichte (kompatibel) und 3) zwei konsistente Maschen haben gemeinsame Kanten und unterschiedliche Kantengewichte (Konflikt). Um alle möglichen, partiell konsistenten Graphen zu synthetisieren, wird der neue Algorithmus CCGsearch eingeführt und auf Vollständigkeit bewiesen. Die Berechnungskomplexitäten der beiden Syntheseverfahren werden sowohl analytisch hergeleitet als auch durch Simulationen verifiziert.Item Open Access The German boundary tones: categorical Perception, perceptual magnets, and the perceptual reference space(2012) Schneider, Katrin; Dogil, Grzegorz (Prof. Dr.)This thesis experimentally analyzes the perception of prosodic categories in German, using the two German boundary tones L% and H% postulated by German phonology. These two boundary tone categories were selected because they constitute the least disputed tonal contrast. In many languages, in German as well, the contrast between the low (L%) and the high (H%) boundary tone corresponds to a contrast in sentence mode. The low boundary tone is interpreted as a statement and the high boundary tone as a question. For all experiments presented in this thesis it is hypothesized that the different perception of L% and H% as statement versus question, respectively, can be attributed to a contrast between two prosodic categories, i.e. to Categorical Perception. The basis for this hypothesis is the observation that the sentence mode of a syntactically ambiguous utterance can only be determined by the height of its boundary tone. Assuming the existence of the two proposed boundary tone categories two experimental designs that can be used to confirm categories, perceptual differences inside a category or perceptual differences between categories are presented. These two designs are the test for the Categorical Perception (CP) and the test for the Perceptual Magnet Effect (PME). Originally, both designs were developed to examine perceptual differences in the segmental domain, especially for the evaluation of phoneme categories. Categorical Perception is confirmed when the boundary between these two categories corresponds to the point at which the discrimination performance between two adjacent stimuli is best. If for two speech events the Categorical Perception test is successful then these two events will be confirmed as being categories of the respective language. A Perceptual Magnet Effect includes a warping of the perceptual space towards a prototype of the respective category. Such a warping does not occur towards a non-prototype of the same category. The result of the warping is a significantly lower discrimination performance around the prototype, i.e. the prototype is not or only hard to discriminate from a adjacent stimulus. Such a warping is not found around a non-prototype, although the acoustic difference between a stimulus and the non-prototype is comparable to the acoustic difference between a stimulus and the prototype. For the analyses and the interpretation of the experimental results the Signal Detection Theory (SDT) and the Exemplar Theory are used. Signal Detection Theory postulates that despite similar auditory abilities subjects may differ in their perceptual results because of their individual response criterion. Exemplar Theory proposes that listeners store their perceived instances of speech events in exemplar clouds located in their perceptual space, and that these instances are stored with much phonetic detail. During speech production, the speaker uses these clouds of similar exemplars to produce an instance of a speech event. Thus, speech perception and production are inseparably connected. The more exemplars are stored the more stable a speech category will get. Only stable categories can develop a category center and a Perceptual Magnet Effect. In various studies reaction times were found to be a reliable indicator for the simplicity of a perceptual decision. Thus, in the experiment presented in this thesis reaction times were measured for each individual decision. The results support the already known correlation, i.e. the more simple a perceptual decision is the lower the reaction time will be. To summarize, the results discussed in this thesis support the existence of prosodic categories in general, and especially those of the high and the low boundary tone in German. These two prosodic categories are used to differentiate between the sentence modes statement versus question, but only in case of syntactically ambiguous phrases. Furthermore, the results support the use on Exemplar Theory for speech data. The category of the low boundary tone seems to contain much more exemplars than the category of the high boundary tone as the latter category is less often produced and thus less often perceived than the first one. This results in a clear Perceptual Magnet Effect for the L% category as there enough exemplar are stored to support the development of a category center, and only in the center of a category the PME can occur. For most listeners the H% category contains only a few exemplars which in turn inhibits the development of a Perceptual Magnet Effect there. The logged reaction times support the perceptual findings and reveal the hypothesis that reaction times correlate with the simplicity of a perceptual decision.Item Open Access Test planning for low-power built-in self test(2014) Zoellin, Christian G.; Wunderlich, Hans-Joachim (Prof. Dr. rer. nat. habil.)Power consumption has become the most important issue in the design of integrated circuits. The power consumption during manufacturing or in-system test of a circuit can significantly exceed the power consumption during functional operation. The excessive power can lead to false test fails or can result in the permanent degradation or destruction of the device under test. Both effects can significantly impact the cost of manufacturing integrated circuits. This work targets power consumption during Built-In Self-Test (BIST). BIST is a Design-for-Test (DfT) technique that adds additional circuitry to a design such that it can be tested at-speed with very little external stimulus. Test planning is the process of computing configurations of the BIST-based tests that optimize the power consumption within the constraints of test time and fault coverage. In this work, a test planning approach is presented that targets the Self-Test Using Multiple-input signature register and Parallel Shift-register sequence generator (STUMPS) DfT architecture. For this purpose, the STUMPS architecture is extended by clock gating in order to leverage the benefits of test planning. The clock of every chain of scan flip-flops can be independently disabled, reducing the switching activity of the flip-flops and their clock distribution to zero as well as reducing the switching activity of the down-stream logic. Further improvements are obtained by clustering the flip-flops of the circuit appropriately. The test planning problem is mapped to a set covering problem. The constraints for the set covering are extracted from fault simulation and the circuit structure such that any valid cover will test every targeted fault at least once. Divide-and-conquer is employed to reduce the computational complexity of optimization against a power consumption metric. The approach can be combined with any fault model and in this work, stuck-at and transition faults are considered. The approach effectively reduces the test power without increasing the test time or reducing the fault coverage. It has proven effective with academic benchmark circuits, several industrial benchmarks and the Synergistic Processing Element (SPE) of the Cell/B.E.™ Processor (Riley et al., 2005). Hardware experiments have been conducted based on the manufacturing BIST of the Cell/B.E.™ Processor and shown the viability of the approach for industrial, high-volume, high-end designs. In order to improve the fault coverage for delay faults, high-frequency circuits are sometimes tested with complex clock sequences that generate test with three or more at-speed cycles (rather than just two of traditional at-speed testing). In order to allow such complex clock sequences to be supported, the test planning presented here has been extended by a circuit graph based approach for determining equivalent combinational circuits for the sequential logic. In addition, this work proposes a method based on dynamic frequency scaling of the shift clock that utilizes a given power envelope to it full extent. This way, the test time can be reduced significantly, in particular if high test coverage is targeted.Item Open Access Automated composition of adaptive pervasive applications in heterogeneous environments(2012) Schuhmann, Stephan Andreas; Rothermel, Kurt (Prof. Dr. rer. nat. Dr. h. c.)Distributed applications for Pervasive Computing represent a research area of high interest. Configuration processes are needed before the application execution to find a composition of components that provides the required functionality. As dynamic pervasive environments and device failures may yield unavailability of arbitrary components and devices at any time, finding and maintaining such a composition represents a nontrivial task. Obviously, many degrees of decentralization and even completely centralized approaches are possible in the calculation of valid configurations, spanning a wide spectrum of possible solutions. As configuration processes produce latencies which are noticed by the application user as undesired waiting times, configurations have to be calculated as fast as possible. While completely distributed configuration is inevitable in infrastructure-less Ad Hoc scenarios, many realistic Pervasive Computing environments are located in heterogeneous environments, where additional computation power of resource-rich devices can be utilized by centralized approaches. However, in case of strongly heterogeneous pervasive environments including several resource-rich and resource-weak devices, both centralized and decentralized approaches may lead to suboptimal results concerning configuration latencies: While the resource-weak devices may be bottlenecks for decentralized configuration, the centralized approach faces the problem of not utilizing parallelism. Most of the conducted projects in Pervasive Computing only focus on one specific type of environment: Either they concentrate on heterogeneous environments, which rely on additional infrastructure devices, leading to inapplicability in infrastructure-less environments. Or they address homogeneous Ad Hoc environments and treat all involved devices as equal, which leads to suboptimal results in case of present resource-rich devices, as their additional computation power is not exploited. Therefore, in this work we propose an advanced comprehensive adaptive approach that particularly focuses on the efficient support of heterogeneous environments, but is also applicable in infrastructure-less homogeneous scenarios. We provide multiple configuration schemes with different degrees of decentralization for distributed applications, optimized for specific scenarios. Our solution is adaptive in a way that the actual scheme is chosen based on the current system environment and calculates application compositions in a resource-aware efficient manner. This ensures high efficiency even in dynamically changing environments. Beyond this, many typical pervasive environments contain a fixed set of applications and devices that are frequently used. In such scenarios, identical resources are part of subsequent configuration calculations. Thus, the involved devices undergo a quite similar configuration process whenever an application is launched. However, starting the configuration from scratch every time not only consumes a lot of time, but also increases communication overhead and energy consumption of the involved devices. Therefore, our solution integrates the results from previous configurations to reduce the severity of the configuration problem in dynamic scenarios. We prove in prototypical real-world evaluations as well as by simulation and emulation that our comprehensive approach provides efficient automated configuration in the complete spectrum of possible application scenarios. This extensive functionality has not been achieved by related projects yet. Thus, our work supplies a significant contribution towards seamless application configuration in Pervasive Computing.Item Open Access Visualization challenges in distributed heterogeneous computing environments(2015) Panagiotidis, Alexandros; Ertl, Thomas (Prof. Dr.)Large-scale computing environments are important for many aspects of modern life. They drive scientific research in biology and physics, facilitate industrial rapid prototyping, and provide information relevant to everyday life such as weather forecasts. Their computational power grows steadily to provide faster response times and to satisfy the demand for higher complexity in simulation models as well as more details and higher resolutions in visualizations. For some years now, the prevailing trend for these large systems is the utilization of additional processors, like graphics processing units. These heterogeneous systems, that employ more than one kind of processor, are becoming increasingly widespread since they provide many benefits, like higher performance or increased energy efficiency. At the same time, they are more challenging and complex to use because the various processing units differ in their architecture and programming model. This heterogeneity is often addressed by abstraction but existing approaches often entail restrictions or are not universally applicable. As these systems also grow in size and complexity, they become more prone to errors and failures. Therefore, developers and users become more interested in resilience besides traditional aspects, like performance and usability. While fault tolerance is well researched in general, it is mostly dismissed in distributed visualization or not adapted to its special requirements. Finally, analysis and tuning of these systems and their software is required to assess their status and to improve their performance. The available tools and methods to capture and evaluate the necessary information are often isolated from the context or not designed for interactive use cases. These problems are amplified in heterogeneous computing environments, since more data is available and required for the analysis. Additionally, real-time feedback is required in distributed visualization to correlate user interactions to performance characteristics and to decide on the validity and correctness of the data and its visualization. This thesis presents contributions to all of these aspects. Two approaches to abstraction are explored for general purpose computing on graphics processing units and visualization in heterogeneous computing environments. The first approach hides details of different processing units and allows using them in a unified manner. The second approach employs per-pixel linked lists as a generic framework for compositing and simplifying order-independent transparency for distributed visualization. Traditional methods for fault tolerance in high performance computing systems are discussed in the context of distributed visualization. On this basis, strategies for fault-tolerant distributed visualization are derived and organized in a taxonomy. Example implementations of these strategies, their trade-offs, and resulting implications are discussed. For analysis, local graph exploration and tuning of volume visualization are evaluated. Challenges in dense graphs like visual clutter, ambiguity, and inclusion of additional attributes are tackled in node-link diagrams using a lens metaphor as well as supplementary views. An exploratory approach for performance analysis and tuning of parallel volume visualization on a large, high-resolution display is evaluated. This thesis takes a broader look at the issues of distributed visualization on large displays and heterogeneous computing environments for the first time. While the presented approaches all solve individual challenges and are successfully employed in this context, their joint utility form a solid basis for future research in this young field. In its entirety, this thesis presents building blocks for robust distributed visualization on current and future heterogeneous visualization environments.Item Open Access German clause-embedding predicates : an extraction and classification approach(2010) Lapshinova-Koltunski, Ekaterina; Heid, Ulrich (Prof. Dr. phil. habil.)This thesis describes a semi-automatic approach to the analysis of subcategorisation properties of verbal, nominal and multiword predicates in German. We semi-automatically classify predicates according to their subcategorisation properties by means of extracting them from German corpora along with their complements. In this work, we concentrate exclusively on sentential complements, such as dass, ob and w-clauses, although our methods can be also applied for other complement types. Our aim is not only to extract and classify predicates but also to compare subcategorisation properties of morphologically related predicates, such as verbs and their nominalisations. It is usually assumed that subcategorisation properties of nominalisations are taken over from their underlying verbs. However, our tests show that there exist different types of relations between them. Thus, we review subcategorisation properties of morphologically related words and analyse their correspondences and differences. For this purpose, we elaborate a set of semi-automatic procedures, which allow us not only to classify extracted units according to their subcategorisation properties, but also to compare the properties of verbs and their nominalisations, which occur both freely in corpora and within a multiword expression. The lexical data are created to serve symbolic NLP, especially large symbolic grammars for deep processing, such as HPSG or LFG, cf. work in the LinGO project (Copestake et al. 2004) and the Pargram project (Butt et al. 2002). HPSG and LFG need detailed linguistic knowledge. Besides that, subcategorisation iformation can be applied in applications for IE, cf. (Surdeanu et al. 2003). Moreover, this information is necessary for linguistic, lexicographic, SLA and translation work. Our extraction and classification procedures are precision-oriented, which means that we focus on high accuracy of our extraction and classification results. High precision is opposed to completeness, which is compensated by the application of extraction procedures on larger corpora.Item Open Access Segmental factors in language proficiency : degree of velarization, coarticulatory resistance and vowel formant frequency distribution as a signature of talent(2011) Baumotte, Henrike; Dogil, Grzegorz (Prof. Dr.)The present PhD proposes a reason for German native speakers of various proficiency levels and multiple English varieties producing their L2 English with different degrees of a foreign accent. The author took into account phonetic measurements to investigate the degree of velarization and coarticulation or coarticulatory resistance respectively in German and English, taking non-words and natural language stimuli. To get an impression of the differences between the productions of proficient, average and less proficient speakers in German and English, the mean F2 and Fv values in /ə/ before /l/ and in /l/ were calculated, for then comparing the degree of velarization in /əlV/ non-word sequences with each other. Proficient speakers gained lower formant frequencies for F2 and Fv in /ə/ than less proficient speakers, i.e. proficient speakers velarized more than less proficient speakers. Within the comparisons with respect to coarticulation or coarticulatory resistance results respectively the difference values for F2 and F2' out of /ə/ in /əleɪ/ vs. /əlu:/, /əly/ vs. /əleɪ/ and /əly/ vs. /əlaɪ/ were created. In the whole series of measurements, an overwhelming trend for proficient speakers being more coarticulatory resistant, i.e. velarizing more, and more precisely pronouncing English vowel characteristics than less proficient speakers was present, while average speakers did not continuously behave according to prediction, as a result of being sometimes “worse” than less proficient speakers. On the basis of Díaz et al. (2008) who pled for pre-existing individual differences in phonetic discrimination ability which enormously influence the achievement of a foreign sound system, it is claimed for a derivation of foreign language from native phonetic abilities.Item Open Access Position sharing for location privacy in non-trusted systems(2015) Skvortsov, Pavel; Rothermel, Kurt (Prof. Dr. rer. nat. Dr. h.c.)Currently, many location-aware applications are available for mobile users of location-based services. Applications such as Google Now, Trace4You or FourSquare are being widely used in various environments where privacy is a critical issue for users. A general solution for preserving location privacy for a user is to degrade the quality of his or her position information. In this work, we propose an approach that uses spatial obfuscation to secure the users’ position information. By revealing the user’s position with a certain degree of obfuscation, the first crucial issue is the tradeoff between privacy and precision. This tradeoff problem is caused by limited trust in the location service providers: higher obfuscation increases privacy but leads to lower quality of service. We overcome this problem by introducing the position sharing approach. Our main idea is that position information is distributed amongst multiple providers in the form of separate data pieces called position shares. Our approach allows for the usage of non-trusted providers and flexibly manages the user’s location privacy level based on probabilistic privacy metrics. In this work, we present the multi-provider based position sharing approach, which includes algorithms for the generation of position shares and share fusion algorithms. The second challenge that must be addressed is that the user’s environmental context can significantly decrease the level of obfuscation. For example, a plane, a boat and a car create different requirements for the obfuscated region. Therefore, it is very important to consider map-awareness in selecting the obfuscated areas. We assume that a static map is known to an adversary, which may help in deriving the user’s true position. We analyze both how map-awareness affects the generation and fusion of position shares and the difference between the map-aware position sharing approach and its open space based version. Our security analysis shows that the proposed position sharing approach provides good security guarantees for both open space and constrained space based models. The third challenge is that multiple location servers and/or their providers may have different trustworthiness from the user’s point of view. In this case, the user would prefer not to reveal an equal level (precision) of position information to every server. We propose a placement optimization approach that ensures that risk is balanced among the location servers according to their individual trust levels. Our evaluation shows significant improvement of privacy guarantees after applying the optimized share distribution, in comparison with the equal share distribution. The fourth related problem is the location update algorithm. A high number of different location servers n (corresponding to n privacy levels) may lead to significant communication overhead. Each update would require n messages from the mobile user to the location servers, especially in cases of high update rate. Therefore, we propose an optimized location update algorithm to decrease the number of messages sent without reducing the number of privacy levels and the user’s privacy.Item Open Access Leistungseffiziente Analog-Digital-Umsetzer mit sukzessivem Approximationsregister(2015) Digel, Johannes; Berroth, Manfred (Prof. Dr.-Ing.)In der Signalverarbeitung und Kommunikation zeichnet sich ein Trend weg vom Analogen hin zum Digitalen ab. Vorteile von digitalen Daten sind, dass ihre physikalische Darstellung losgelöst davon ist, was sie physikalisch repräsentieren, dass zu ihrer Verarbeitung standardisierte Schaltungskomponenten angewendet und spezialisierte Komponenten synthetisiert werden können, sowie dass sie verlustfrei übertragen und gespeichert werden können. Dafür müssen analoge Signale, die beispielsweise von einem Sensor generiert oder von einer Antenne empfangen werden, verstärkt und anschließend in digitale Daten umgesetzt werden. Für die Analog-Digital-Umsetzung sind unterschiedliche Konzepte bekannt, von denen sich manche besonders gut für bestimmte Technologien eignen. Die Konzepte unterscheiden sich durch die Kennzahlen und Parameter, die mit ihnen erreicht werden können. Eines der Konzepte, um ein analoges in ein digitales Signal umzusetzen, nennt sich „Sukzessive Approximation“. Dieses Konzept verwendet ein schrittweises, binär abgestuftes Wägeverfahren, um die digitale Repräsentation einer analogen Spannung zu bestimmen. Wegen seines schrittweisen Fortschritts erlaubt es grundsätzlich eine Analog-Digital-Umsetzung mit mittlerer Geschwindigkeit. Die Abtastrate kann jedoch erhöht werden, indem einige Umsetzer mit Zeitverschachtelung arbeiten. Der Analog-Digital-Umsetzer mit sukzessiver Approximation erreicht mittlere Auflösungen im Bereich von 10 bit, ohne dass er eine Kalibrierung oder Kompensation von Fehlern benötigt. Jede weitere Erhöhung der Auflösung um ein Bit fügt dem Umsetzungszyklus einen Schritt hinzu, alle Komponenten müssen jedoch die Anforderungen in Bezug auf Rauschen, Linearität und Genauigkeit für die geforderte Auflösung erfüllen. Der Analog-Digital-Umsetzer mit sukzessiver Approximation beinhaltet ein sukzessives Approximationsregister, das mit statischer CMOS-Logik arbeitet. Es speichert das digitale Ausgangscodewort des Umsetzers und steuert den Umsetzungszyklus. Eine weitere Komponente ist durch einen Digital-Analog-Umsetzer gegeben, der für gewöhnlich als passive Schaltung mit einem kapazitiven Spannungsteiler mit binär gewichteten Kondensatoren realisiert wird. Die einzige aktive, analoge Komponente dieses Umsetzers ist ein Komparator, der entscheidet, ob ein Binärwert „0“ oder „1“ ist. Wegen der geringen Anzahl an aktiven, analogen Komponenten eignen sich moderne CMOS-Technologien besonders für Analog-Digital-Umsetzer mit sukzessiver Approximation und ermöglichen sehr leistungseffiziente Entwürfe. Veröffentlichte Entwürfe von Analog-Digital-Umsetzern mit sukzessiver Approximation mit Abtastraten im Bereich von einigen Kilosamples bis zu dutzenden Gigasamples pro Sekunde zeigen eine sehr gute Leistungseffizienz. Sie eignen sich für ein großes Anwendungsfeld wie für biomedizinische Beobachtung, Sensorsysteme, die Beobachtung analoger Spannungen innerhalb einer Schaltung oder drahtlose oder -gebundene Kommunikation. Wegen ihrer Kompatibilität mit skalierten CMOS-Technologien können sie zusammen mit digitalen Schaltungen zur Signalverarbeitung in einem Mikrochip integriert werden. Diese Arbeit behandelt den Entwurf von Analog-Digital-Umsetzern mit sukzessiver Approximation, die Abtastraten im Bereich von Megasamples pro Sekunde haben. Die vorgestellten Komponenten sollen den Entwurf von Umsetzern mit gegebenen Anforderungen in einer gebräuchlichen Technologie ermöglichen. Dabei soll eine dem Stand der Technik entsprechende Leistungseffizienz erreichbar sein, ohne dass die Schaltung eine komplexe Kalibrierung oder Fehlerkorrektur benötigt. Die vorgestellten Entwürfe beschränken sich auf Umsetzer mit einem Kern, die ohne Zeitverschachtelung arbeiten. Alle enthaltenen Umsetzer beinhalten genau einen Komparator, der einen Binärwert pro Vergleich bestimmt. Damit wird in jedem Schritt des Umsetzungszyklus genau ein Bit bestimmt. Nach der Einführung grundlegender Eigenschaften und Parameter von Analog-Digital-Umsetzern werden einige Konzepte und Algorithmen für die sukzessive Approximation angegeben. Es werden alle Schaltungsblöcke vorgestellt, die zur Realisierung der aufgeführten Algorithmen notwendig sind. Besondere Beachtung finden die begrenzenden Eigenschaften eines jeden Blocks wie die Linearität des Eingangskreises, die Empfindlichkeit des Entscheiders oder der Einfluss von Prozessschwankungen. Für alle gezeigten Schaltungsvarianten werden gefertigte Analog-Digital-Umsetzer zusammen mit den zugehörigen Messergebnissen gezeigt. Das Abschlusskapitel ordnet die in dieser Arbeit entworfenen Schaltungen in den Stand der Technik ein.