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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Adjustable white-light emission from a photo-structured micro-OLED array

Krotkus, Simonas, Kasemann, Daniel, Lenk, Simone, Leo, Karl, Reineke, Sebastian 10 January 2017 (has links)
White organic light-emitting diodes (OLEDs) are promising candidates for future solid-state lighting applications and backplane illumination in large-area displays. One very specific feature of OLEDs, which is currently gaining momentum, is that they can enable tunable white light emission. This feature is conventionally realized either through the vertical stacking of independent OLEDs emitting different colors or in lateral arrangement of OLEDs. The vertical design is optically difficult to optimize and often results in efficiency compromises between the units. In contrast, the lateral concept introduces severe area losses to dark regions between the subunits, which requires a significantly larger overall device area to achieve equal brightness. Here we demonstrate a color-tunable, two-color OLED device realized by side-by-side alignment of yellow and blue p-i-n OLEDs structured down to 20 μm by a simple and up-scalable orthogonal photolithography technique. This layout eliminates the problems of conventional lateral approaches by utilizing all area for light emission. The corresponding emission of the photo-patterned two-unit OLED can be tuned over a wide range from yellow to white to blue colors. The independent control of the different units allows the desired overall spectrum to be set at any given brightness level. Operated as a white light source, the microstructured OLED reaches a luminous efficacy of 13 lm W−1 at 1000 cd m−2 without an additional light outcoupling enhancement and reaches a color rendering index of 68 when operated near the color point E. Finally, we demonstrate an improved device lifetime by means of size variation of the subunits.
92

The impact of molecular weight, air exposure and molecular doping on the charge transport properties and electronic defects in dithienyldiketopyrrolopyrrole- thieno[3,2-b]thiophene copolymers

Di Pietro, Riccardo, Erdmann, Tim, Wang, Naixiang, Liu, Xuhai, Gräfe, David, Lenz, Johannes, Brandt, Josef, Kasemann, Daniel, Leo, Karl, Al-Hussein, Mahmoud, Gerasimov, Kirill L., Doblas, David, Ivanov, Dimitri A., Voit, Brigitte, Neher, Dieter, Kiriy, Anton 10 January 2020 (has links)
We performed an in-depth study of high molecular weight poly[3,6-(dithiophene-2-yl)-2,5-di(2-octyldodecyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-thieno[3,2-b]thiophene] P(DPP2OD-TT) synthesized through the Stille coupling polycondensation in order to understand the correlation between molecular weight, processing conditions and charge transport. We observed a rapid increase in its aggregation in solution with increasing molecular weight which strongly limits the solubility and processability for weight average molecular weights beyond 200 kg mol⁻¹. This results in severe limitation in the charge transport properties of the polymer. We further observe the presence of bulk electronic defects in all different polymer batches that severely limit the current flow and manifest themselves in organic field effect transistors as apparent charge density dependence of the mobility. These defects are passivated by exposure to an ambient atmosphere, as confirmed by an increase in current and mobility that is no more charge density dependent. This is further confirmed by the result of chemical doping using 2,2-(perfluoronaphthalene-2,6-diylidene)dimalononitrile, F₆TCNNQ, which leads to the filling of the trap states and a higher charge density independent mobility of up to 1 cm2 V⁻¹ s⁻¹.
93

AL: Unified Analytics in Domain Specific Terms

Luong, Johannes, Habich, Dirk, Lehner, Wolfgang 13 June 2022 (has links)
Data driven organizations gather information on various aspects of their endeavours and analyze that information to gain valuable insights or to increase automatization. Today, these organizations can choose from a wealth of specialized analytical libraries and platforms to meet their functional and non-functional requirements. Indeed, many common application scenarios involve the combination of multiple such libraries and platforms in order to provide a holistic perspective. Due to the scattered landscape of specialized analytical tools, this integration can result in complex and hard to evolve applications. In addition, the necessary movement of data between tools and formats can introduce a serious performance penalty. In this article we present a unified programming environment for analytical applications. The environment includes AL, a programming language that combines concepts of various common analytical domains. Further, the environment also includes a flexible compilation system that uses a language-, domain-, and platform independent program intermediate representation to separate high level application logic and physical organisation. We provide a detailed introduction of AL, establish our program intermediate representation as a generally useful abstraction, and give a detailed explanation of the translation of AL programs into workloads for our experimental shared-memory processing engine.
94

Conjunctive Queries with Inequalities Under Updates

Idris, Muhammad, Ugarte, Martín, Vansummeren, Stijn, Voigt, Hannes, Lehner, Wolfgang 15 June 2022 (has links)
Modern application domains such as Composite Event Recognition (CER) and real-time Analytics require the ability to dynamically refresh query results under high update rates. Traditional approaches to this problem are based either on the materialization of subresults (to avoid their recomputation) or on the recomputation of subresults (to avoid the space overhead of materialization). Both techniques have recently been shown suboptimal: instead of materializing results and subresults, one can maintain a data structure that supports efficient maintenance under updates and can quickly enumerate the full query output, as well as the changes produced under single updates. Unfortunately, these data structures have been developed only for aggregate-join queries composed of equi-joins, limiting their applicability in domains such as CER where temporal joins are commonplace. In this paper, we present a new approach for dynamically evaluating queries with multi-way θ-joins under updates that is effective in avoiding both materialization and recomputation of results, while supporting a wide range of applications. To do this we generalize Dynamic Yannakakis, an algorithm for dynamically processing acyclic equi-join queries. In tandem, and of independent interest, we generalize the notions of acyclicity and free-connexity to arbitrary θ-joins. We instantiate our framework to the case where θ-joins are only composed of equalities and inequalities (<, ≤, =, >, ≥) and experimentally compare this algorithm, called IEDyn, to state of the art CER systems as well as incremental view maintenance engines. IEDyn performs consistently better than the competitor systems with up to two orders of magnitude improvements in both time and memory consumption.
95

Direct laser interference patterning of metallic sleeves for roll-to-roll hot embossing

Lang, Valentin, Rank, Andreas, Lasagni, Andrés Fabián 05 September 2019 (has links)
Surfaces equipped with periodic patterns with feature sizes in the micrometer, submicrometer and nanometer range present outstanding surface properties. Many of these surfaces can be found on different plants and animals. However, there are few methods capable to produce such patterns in a one-step process on relevant technological materials. Direct laser interference patterning (DLIP) provides both high resolution as well as high throughput. Recently, fabrication rates up to 1 m²·min-1 could be achieved. However, resolution was limited to a few micrometers due to typical thermal effects that arise when nanosecond pulsed laser systems are used. Therefore, this study introduces an alternative to ns-DLIP for the fabrication of multi-scaled micrometer and submicrometer structures on nickel surfaces using picosecond pulses (10 ps at a wavelength of 1064 nm). Due to the nature of the interaction process of the metallic surfaces with the ultrashort laser pulses, it was not only possible to directly transfer the shape of the interference pattern intensity distribution to the material (with spatial periods ranging from 1.5 μm to 5.7 μm), but also to selectively obtain laser induce periodic surface structures with feature sizes in the submicrometer and nanometer range. Finally, the structured nickel sleeves are utilized in a roll-to-roll hot embossing unit for structuring of polymer foils. Processing speeds up to 25 m·min-1 are reported.
96

Demonstrating Efficient Query Processing in Heterogeneous Environments

Karnagel, Tomas, Hille, Matthias, Ludwig, Mario, Habich, Dirk, Lehner, Wolfgang, Heimel, Max, Markl, Volker 30 June 2022 (has links)
The increasing heterogeneity in hardware systems gives developers many opportunities to add more functionality and computational power to the system. As a consequence, modern database systems will need to be able to adapt to a wide variety of heterogeneous architectures. While porting single operators to accelerator architectures is well-understood, a more generic approach is needed for the whole database system. In prior work, we presented a generic hardware-oblivious database system, where the operators can be executed on the main processor as well as on a large number of accelerator architectures. However, to achieve fully heterogeneous query processing, placement decisions are needed for the database operators. We enhance the presented system with heterogeneity-aware operator placement (HOP) to take a major step towards designing a database system that can efficiently exploit highly heterogeneous hardware environments. In this demonstration, we are focusing on the placement-integration aspect as well as presenting the resulting database system.
97

Polypropylene and Natural Rubber based Thermoplastic Vulcanizates by Electron Induced Reactive Processing: Polypropylene and Natural Rubber based Thermoplastic Vulcanizates by Electron Induced Reactive Processing

Mondal, Manas 26 September 2013 (has links)
Thermoplastic Vulcanizates (TPVs) are itself a commercially high valued group of polymer blend. They render technological properties of conventional vulcanized elastomers with the ease of thermoplastic melt (re)processability. With ever growing market, TPVs have got plenty of applications among various fields. Here, the technological properties of these TPVs were tailored according to the purpose by interplaying physical parameters of polymers and advanced high energy electron technology. Electron irradiation, though a well-known technique for cross-linking in polymer industry, is only restricted to final product treatment. We take it to the next level by coupling a conventional internal mixer and a high energy electron accelerator. Polypropylene (PP) and natural rubber (NR) based TPVs have been prepared using this new reactive processing technology, named Electron Induced Reactive Processing (EIReP). Various electron treatment parameters were explored to maximize technological properties of TPVs. Effects of various polyfunctional monomers (PFM) were also studied. In an endeavor to develop a potential method for customization, deep insights of macroscopic and microscopic structure of these TPVs were presented with the help of various advanced scientific characterization techniques. Commonly faced difficulties like viscosity mismatch, cure rate mismatch, and incompatibility due to different molecular structures were furnished along with plausible solutions. Investigation of phase inversion from co-continuous matrix to thermoplastic matrix was dealt with special care as it helps to understand structure property correlation for all TPVs. To make the whole effort relevant, at the end of this thesis a summary of various technological properties has been given for the newly processed and commercially available TPVs.
98

Identification of Essential Components and Novel Regulators of Non-canonical and DNA damage-induced NF-κB Pathways

Tufan, Ahmet Bugra 17 December 2021 (has links)
Als Reaktion auf DNA-Schäden aktivieren Zellen den NF-κB-Signalweg, der die apoptotischen Reaktionen reguliert. Die Signalwege, die die zytoplasmatischen NF-κB-Dimere als Reaktion auf eine breite Palette von Immun- und Entzündungssignalen aktivieren, sind umfassend untersucht worden; die molekularen Mechanismen, die die Kern-DNA mit der zytoplasmatischen Aktivierung von NF-κB verbinden, sind jedoch relativ wenig bekannt. Hier haben wir mithilfe genomweiter siRNA-Screens systematisch Regulatoren und wesentliche Komponenten identifiziert, die für die durch DNA-Schäden ausgelöste Aktivierung des NF-κB-Signalwegs erforderlich sind. Von den identifizierten Komponenten konnten wir nachweisen, dass TSG101 die NF-κB-Aktivierung durch DNA-Schäden reguliert. Wir konnten zeigen, dass TSG101 mit PARP1 interagiert und dessen katalytische Aktivität kontrolliert. Die Ausrichtung auf TSG101 führt dazu, dass PARP1 in DNA-Läsionen gefangen wird und die durch DNA-Schäden ausgelöste NF-κB-Aktivierung vermindert wird. In Abwesenheit von TSG101 fehlen den Zellen PAR-abhängige zelluläre Reaktionen und sie sind für die durch DNA-Schäden ausgelöste Apoptose sensibilisiert. Die signalinduzierte Verarbeitung von p100 ist ein wesentlicher Schritt für die Aktivierung des nicht-kanonischen NF-κB-Wegs. Trotz seiner Bedeutung für die Immunantwort, die Entwicklung und verschiedene bösartige Erkrankungen wurden die Komponenten des Ubiquitin-Proteasom-Systems, die die Verarbeitung von p100 regulieren, nie mit endogenen Systemen analysiert. In dieser Studie haben wir mit Hilfe eines CRISPR-Cas9-basierten Knock-out-Screening-Systems nicht-redundante E3-Ligasen identifiziert, die für die signalinduzierte p100-Verarbeitung erforderlich sind. Außerdem haben wir das TWEAK-induzierte Ubiquitinom mittels Massenspektrometrie charakterisiert. / In response to DNA damage, cells activate the NF-κB pathway that regulates the apoptotic responses. The signaling pathways that activate the cytoplasmic NF-κB dimers in response to a wide range of immune and inflammatory signals have been investigated extensively; however, the molecular mechanisms that link the nuclear DNA with cytoplasmic activation of NF-κB is relatively less known. Here we systematically identified regulators and essential components required for the DNA damage-induced activation of the NF-κB pathway using genome-wide siRNA screens. Amongst the identified components, we validated that TSG101 regulates the NF-κB activation by DNA damage. We showed that TSG101 interacts with PARP1 and controls its catalytic activity. Targeting TSG101 consequently achieves trapping of PARP1 in DNA lesions and diminishes the DNA damage-induced NF-κB activation. In the absence of TSG101, cells lack PAR-dependent cellular responses and are sensitized to DNA damage-induced apoptosis. The signal-induced processing of p100 is an essential step for the activation of the non-canonical NF-κB pathway. Despite of its importance in immune responses, development, and several malignancies, the ubiquitin-proteasome system components regulating p100 processing were never analyzed using endogenous systems. In this study, utilizing a CRISPR Cas9 based knock out screening system we identified non-redundant E3 ligases required for the signal-induced p100 processing. We also characterized the TWEAK-induced ubiquitinome via mass spectrometry.
99

Gender agreement in Native and Heritage Greek: an attraction study

Paspali, Anastasia 29 November 2019 (has links)
Diese Dissertation betrachtet die Beziehung zwischen Parser und Grammatik bei Muttersprachlern (Native Speakers, NS) und Heritage- (Erb-) Sprechern (HS) des Griechischen, indem sie die Mechanismen untersucht, die einer pseudo-Lizenzierung bei Verletzungen der Kongruenz des grammatischen Geschlechts zugrunde liegen. Diese Verletzungen sind Fehler, die auftreten, wenn eine intervenierende Phrase (Attraktor) nicht mit den Genusmerkmalen des Kopfnomens übereinstimmt, ein Phänomen, das in der Literatur (Gender-)Agreement Attraktion, hier Attraktion von Genuskongruenz, genannt wird. Die Dissertation testet, ob eine solche Attraktion von Genuskongruenz im Griechischen vorhanden ist und ob ein- und zweisprachige Muttersprachler gleichermaßen anfällig für Fehler bei der Attraktion sind. Die Dissertation untersucht für die Gruppe der HS außerdem die Genuskongruenz beim Echtzeit-Sprachverstehen und -produzieren. In der Arbeit zeige ich, dass sowohl NS als auch HS anfällig für Attraktionsfehler bei der Genuskongruenz sind. Das zeigen die Reaktionszeitmuster und die Urteile. Gleichzeitig zeigten bei mündlichen Erzählungen beide Sprechergruppen die gleichen Übergeneralisierungsmuster für maskulines Genus bei belebten Nomen sowie bei mündlichen Erzählungen und beschleunigten Grammatikalitätsurteilen für Neutrum bei unbelebten Nomen. Zusammengenommen deuten diese Ergebnisse darauf hin, dass NS und HS anfällig für die Attraktion von Genuskongruenz sind und dass beide Gruppen ähnliche Hinweise zum Abruf des Genus verwenden und somit ähnliche Attraktionsmuster aufweisen. HS unterscheiden sich jedoch von NS in der Verarbeitung der Genuskongruenz an sich, insbesondere bei femininen Kopfnomen (markiertes Genus) in Objekt-Klitika, was darauf hindeutet, dass sowohl Markiertheit als auch Kongruenz an den Schnittstellen die Leistung von HS beeinflusst. Wenn Fehler auftreten, folgen beide Gruppen den gleichen Mustern der Übergeneralisierung. / This dissertation explores the relationship between the parser and the grammar in Native Speakers (NSs) and Heritage Speakers (HSs) of Greek by examining the mechanisms underpinning the illusory licensing of gender agreement violations: errors occurring when an intervening phrase (attractor) mismatches the gender cues of the head noun, a phenomenon which is usually called (gender) agreement attraction. In this work, I show that both NSs and HSs are prone to gender agreement attraction errors in the nominal domain of Greek, as their reaction time patterns and (speeded or scaled) judgements revealed. At the same time, both groups showed the same overgeneralization patterns of the masculine value in agreement errors with animate nouns in their oral narrations, and of the neuter value with inanimate nouns in their oral narrations and their online speeded judgements. Taken together, these results suggest that NSs and HSs are prone to gender agreement attraction in Greek and that both groups employ retrieval cues similarly showing similar attraction patterns. However, HSs differ from NSs in the processing of gender agreement per se, particularly with feminine head nouns (marked gender value) on object-clitics, suggesting that markedness as well as agreement at Interfaces influence HSs’ performance. Finally, when errors occur, both groups follow the same overegeneralization patterns.
100

Design of a Robust and Flexible Grammar for Speech Control

Ludyga, Tomasz 28 May 2024 (has links)
Voice interaction is an established automatization and accessibility feature. While many satisfactory speech recognition solutions are available today, the interpretation of text se-mantic is in some use-cases difficult. Differentiated can be two types of text semantic ex-traction models: probabilistic and pure rule-based. Rule-based reasoning is formalizable into grammars and enables fast language validation, transparent decision-making and easy customization. In this thesis we develop a context-free ANTLR semantic grammar to control software by speech in a medical, smart glasses related, domain. The implementation is preceded by research of state-of-the-art, requirements consultation and a thorough design of reusable system abstractions. Design includes definitions of DSL, meta grammar, generic system ar-chitecture and tool support. Additionally, we investigate trivial and experimental grammar improvement techniques. Due to multifaceted flexibility and robustness of the designed framework, we indicate its usability in critical and adaptive systems. We determine 75% semantic recognition accuracy in the medical main use-case. We compare it against se-mantic extraction using SpaCy and two fine-tuned AI classifiers. The evaluation reveals high accuracy of BERT for sequence classification and big potential of hybrid solutions with AI techniques on top grammars, essentially for detection of alerts. The accuracy is strong dependent on input quality, highlighting the importance of speech recognition tailored to specific vocabulary.:1 Introduction 1 1.1 Motivation 1 1.2 CAIS.ME Project 2 1.3 Problem Statement 2 1.4 Thesis Overview 3 2 Related Work 4 3 Foundational Concepts and Systems 6 3.1 Human-Computer Interaction in Speech 6 3.2 Speech Recognition 7 3.2.1 Open-source technologies 8 3.2.2 Other technologies 9 3.3 Language Recognition 9 3.3.1 Regular expressions 10 3.3.2 Lexical tokenization 10 3.3.3 Parsing 10 3.3.4 Domain Specific Languages 11 3.3.5 Formal grammars 11 3.3.6 Natural Language Processing 12 3.3.7 Model-Driven Engineering 14 4 State-of-the-Art: Grammars 15 4.1 Overview 15 4.2 Workbenches for Grammar Design 16 4.2.1 ANTLR 16 4.2.2 Xtext 17 4.2.3 JetBrains MPS 17 4.2.4 Other tools 18 4.3 Design Approaches 19 5 Problem Analysis 23 5.1 Methodology 23 5.2 Identification of Use-Cases 24 5.3 Requirements Analysis 26 5.3.1 Functional requirements 26 5.3.2 Qualitative requirements 26 5.3.3 Acceptance criteria 27 6 Design 29 6.1 Preprocessing 29 6.2 Underlying Domain Specific Modelling 31 6.2.1 Language model definition 31 6.2.2 Formalization 32 6.2.3 Constraints 32 6.3 Generic Grammar Syntax 33 6.4 Architecture 36 6.5 Integration of AI Techniques 38 6.6 Grammar Improvement 40 6.6.1 Identification of synonyms 40 6.6.2 Automatic addition of synonyms 42 6.6.3 Addition of same-meaning strings 42 6.6.4 Addition and modification of rules 43 6.7 Processing of unrecognized input 44 6.8 Summary 45 7 Implementation and Evaluation 47 7.1 Development Environment 47 7.2 Implementation 48 7.2.1 Grammar model transformation 48 7.2.2 Output construction 50 7.2.3 Testing 50 7.2.4 Reusability for similar use-cases 51 7.3 Limitations and Challenges 52 7.4 Comparison to NLP Solutions 54 8 Conclusion 58 8.1 Summary of Findings 58 8.2 Future Research and Development 60 Acronyms 62 Bibliography 63 List of Figures 73 List of Tables 74 List of Listings 75

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