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Learning-Based Quality of Service Prediction in Cellular Vehicle Communication
No full textNetwork communication has become a part of everyday life, and the interconnection among devices and people will increase even more in the future. A new area where this development is on the rise is the field of connected vehicles. It is especially useful for automated vehicles in order to connect the vehicles with other road users or cloud services. In particular for the latter it is beneficial to establish a mobile network connection, as it is already widely used and no additional infrastructure is needed. With the use of network communication, certain requirements come along.
One of them is the reliability of the connection. Certain Quality of Service (QoS) parameters need to be met. In case of degraded QoS, according to the SAE level specification, a downgrade of the automated system can be required, which may lead to a takeover maneuver, in which control is returned back to the driver. Since such a handover takes time, prediction is necessary to forecast the network quality for the next few seconds. Prediction of QoS parameters, especially in terms of Throughput (TP) and Latency (LA), is still a challenging task, as the wireless transmission properties of a moving mobile network connection are undergoing fluctuation. In this thesis, a new approach for prediction Network Quality Parameters (NQPs) on Transmission Control Protocol (TCP) level is presented. It combines the knowledge of the environment with the low level parameters of the mobile network. The aim of this work is to perform a comprehensive study of various models including both Location Smoothing (LS) grid maps and Learning Based (LB) regression ones. Moreover, the possibility of using the location independence of a model as well as suitability for automated driving is evaluated.Netzwerkkommunikation ist zu einem Teil des täglichen Lebens geworden, und die Vernetzung von Geräten und Menschen wird in Zukunft noch weiter zunehmen. Ein neuer Bereich, in dem diese Entwicklung zunimmt, sind vernetzte Fahrzeuge. Es ist vorteilhaft automatisierte Fahrzeuge mit anderen Verkehrsteilnehmern oder Cloud-Diensten zu verbinden. Insbesondere für letztere ist der Einsatz einer mobilen Netzwerkverbindung zweckmäßig, da sie bereits weit verbreitet ist und keine zusätzliche Infrastruktur erfordert. Mit der Nutzung des Netzwerkes gehen auch einige Anforderungen einher. Die Zuverlässigkeit der Verbindung ist entscheidend. Kann keine ausreichende Qualität der Verbindung erfüllt werden kann nach SAE Spezifikation das Herunterstufen der Automatisierungsstufe erforderlich sein. In letzter Konsequenz kann diese schließlich zu einem Übernahmemanöver führen, wobei die Kontrolle wieder an den Fahrer zurückgegeben wird. Da ein solcher Wechsel Zeit in Anspruch nimmt, ist eine Vorhersage erforderlich, um die Netzqualität in den nächsten Sekunden zu prognostizieren.
Eine solche Vorhersage der Dienstgüte (Quality of Service (QoS)), besonders hinsichtlich Durchsatz und Latenz, nach wie vor eine recht anspruchsvolle Aufgabe, da die drahtlosen Übertragungseigenschaften einer sich bewegenden mobilen Netzwerkverbindung großen Schwankungen unterliegen. In dieser Dissertation wird ein neuer Ansatz für die Vorhersage von Network Quality Parameters (NQPs) auf der Ebene des Transmission Control Protocol (TCP) vorgestellt. Er kombiniert das Wissen der Umgebung mit den Parametern des Mobilfunknetzes. Das Ziel dieser Arbeit ist eine umfangreiche Untersuchung verschiedener Modelle, darunter sind sowohl Lokalisationsglättende Kachel-Karten wie auch Regressionsverfahren aus dem Bereich des Maschinellen Lernens. Darüber hinaus wird dessen die Möglichkeit der Nutzung der Ortsunabhängigkeit eines Modells erörtert sowie Eignung für automatisiertes Fahren evaluiert
Gleitender Vermögenserwerb im Zugewinnausgleich - Eine Fallstudie anhand von lebenslangen Leistungspflichten und Nutzungsrechten an Immobilien für Fälle bei Ehescheidung
No full textBei landwirtschaftlichen Betriebsübergaben auf die nachfolgende Generation wird der übergebenden Partei als Gegenleistung oftmals ein lebenslanges Wohnrecht auf dem übertragenen Hof gewährt. Die Modalitäten einer derartigen landwirtschaftlichen Betriebsübergabe werden typischerweise in notariell beurkundeten Verträgen geregelt. Mit Hilfe dieser Verträge lassen sich bereits viele Probleme des lebenslangen Wohnrechts regeln. Aufgrund der ständigen Dynamik im Leben der Menschen und des lebenslangen Charakters des lebenslangen Wohnrechts ist es aber wahrscheinlich, dass immer wieder Konstellationen und Ereignisse eintreten, die nicht vertraglich geregelt wurden - vielleicht auch nicht vorhersehbar waren - und trotzdem durch das eingeräumte Recht beeinflusst werden oder mit diesem in Berührung kommen.
Ein unvorhergesehenes Ereignis im Leben kann das Scheitern einer Beziehung zwischen zwei Personen sein. Gerade in Fällen der Ehescheidung kann - sofern auch keine weiteren ehevertraglichen Regelungen vorhanden sind - ein lebenslanges Wohnungsrecht aus einer vorhergehenden Betriebsübergabe zu komplizierten rechtlichen Fallkonstellationen führen. Hat die betriebsübernehmende Partei die mit einem lebenslangen Wohnrecht belastete Immobilie beispielsweise nach Eingehung der Ehe mit Rücksicht auf ein künftiges Erbrecht erworben und wird die Ehe nach der Übertragung der Immobilie geschieden, so stellt sich nämlich die Frage, ob und inwieweit die Immobilie mit dem lebenslangen Wohnrecht im Zugewinnausgleich zu berücksichtigen ist. Aber nicht nur die Immobilie selbst kann hier den Zugewinn beeinflussen. Da das Wohnrecht lebenslang eingeräumt wurde, stellt sich auch die Frage, ob und inwieweit das zunehmende Alter der Wohnrechtsbegünstigten den Wert von Wohnrecht und Immobilie beeinflusst. Eine fortlaufende altersbedingte Wertabnahme des Wohnrechts könnte einen Vermögenszuwachs beim geschiedenen Ehegatten hervorrufen und damit Auswirkungen auf den Zugewinn haben. Dieses Problem wird mit dem Begriff „gleitender Vermögenserwerb“ umschrieben.
Gerade mit dem Problem des gleitenden Vermögenserwerbs setzt sich die Dissertation auseinander und überprüft die materiellen und verfahrensrechtlichen Konsequenzen einer lebenslangen Belastung an Immobilien im Zugewinnausgleich. Dabei werden auch die unterschiedlichen Arten von Nutzungsrechten und Leistungspflichten betrachtet, mit denen die Immobilie belastet ist oder die als Ausgleichsleistung für die Immobilienübertragung erbracht werden. Der Umfang der Dissertation wird hierbei auf die Nutzungsrechte und Leistungspflichten mit Bezug zum Recht auf Wohnen und Lebensunterhalt begrenzt. Die Problematik des gleitenden Vermögenserwerbs wird an Fällen dargestellt, in denen die Ehe durch Ehescheidung beendet wurde
Data as a Common Good: Essays on Data Portability and B2B Industrial Data Sharing
No full textData is an important resource in our economy and society, substantially improving overall business efficiency, innovativeness and competitiveness, and shaping our everyday lives. Yet, to leverage the data's full potential, its access and availability is vital. Thus, data sharing across organizations is of particular importance. This thesis examines the role of data sharing in the digital economy and contributes to a better understanding why data sharing matters, why it is still underutilized, and how data sharing can be encouraged. Thereby, the thesis contributes to the ongoing academic debate as well as the practical and political efforts on how to promote data sharing.
The thesis is comprised of three studies. Study 1 examines personal data sharing among (competing) online services. Particularly, it investigates the consequences of Article 20 in the General Data Protection Regulation (GDPR, May 2018), ensuring the right to data portability. This relatively new right allows online service users to transfer any personal data from one service provider to another. Focusing on a) the amount of data provided by users and b) the amount of user data disclosed to third party data brokers by service providers, the study investigates the right to data portability's effect on competitiveness and consumer surplus. Study 2 and Study 3 focus on non-personal data sharing among competing firms. Study 2 examines the literature to identify and classify barriers to non-personal, machine-generated data sharing. The study explains firms' reluctance to sharing data and discusses policy and managerial implications for overcoming the data sharing barriers. Study 3 focuses on data sharing via platforms. It investigates the Business-to-Business (B2B) data sharing platform design implications for promoting industrial data sharing. In particular, Study 3 investigates the dimensions control and transparency regarding their effect in eliciting cooperation and encouraging data sharing among firms.
In summary, this thesis examines and reveals how access and availability of data can be increased through creating beneficial data sharing conditions in B2B relationships. Particularly, the thesis contributes to the understanding of a) the implications of data sharing laws, defined in the GDPR for personal data and b) the challenges and measures of the not yet successfully established, non-personal data sharing
The diffusion of modern energy technologies in low-income settings - evidence from rural sub-Saharan Africa
No full textThis collection of three chapters responds to today’s energy challenges. It explores innovative policy aimed to equip the energy poor with access to improved cooking energy and electricity, looking both at the demand and supply side of modern energy technologies. Concretely, it discusses mechanisms to increase uptake of off-grid solar electricity in rural Rwanda based on experimental demand measurements (Chapter 1), it studies how to diffuse improved cooking technologies in rural Senegal via supply-side mechanisms (Chapter 2), and it identifies the need to target cooking technologies in consideration of the broader household context in rural Senegal and beyond (Chapter 3)
Holomorphic Extensions in the Structure R_{an,exp}
No full textIn this thesis we consider real analytic functions, i.e. functions which can be described locally as convergent power series and ask the following: Which real analytic functions definable in R_{an,exp} have a holomorphic extension which is again definable in R_{an,exp}? Finding a holomorphic extension is of course not difficult simply by power series expansion. The difficulty is to construct it in a definably way.
We will not answer the question above completely, but introduce a large non trivial class of definable functions in R_{an,exp} where for example functions which are iterated compositions from either side of globally subanalytic functions and the global logarithm are contained. We call them restricted log-exp-analytic. After giving some preliminary results like preparation theorems and Tamm's Theorem for this class of functions we are able to show that real analytic restricted log-exp-analytic functions have a holomorphic extension which is again restricted log-exp-analytic
The power of random information for numerical approximation and integration
No full textThis thesis investigates the quality of randomly collected data by employing a framework built on information-based complexity, a field related to the numerical analysis of abstract problems. The quality or power of gathered information is measured by its radius which is the uniform error obtainable by the best possible algorithm using it. The main aim is to present progress towards understanding the power of random information for approximation and integration problems.
In the first problem considered, information given by linear functionals is used to recover vectors, in particular from generalized ellipsoids. This is related to the approximation of diagonal operators which are important objects of study in the theory of function spaces. We obtain upper bounds on the radius of random information both in a convex and a quasi-normed setting, which extend and, in some cases, improve existing results. We conjecture and partially establish that the power of random information is subject to a dichotomy determined by the decay of the length of the semiaxes of the generalized ellipsoid.
Second, we study multivariate approximation and integration using information given by function values at sampling point sets. We obtain an asymptotic characterization of the radius of information in terms of a geometric measure of equidistribution, the distortion, which is well known in the theory of quantization of measures. This holds for isotropic Sobolev as well as Hölder and Triebel-Lizorkin spaces on bounded convex domains. We obtain that for these spaces, depending on the parameters involved, typical point sets are either asymptotically optimal or worse by a logarithmic factor, again extending and improving existing results.
Further, we study isotropic discrepancy which is related to numerical integration using linear algorithms with equal weights. In particular, we analyze the quality of lattice point sets with respect to this criterion and obtain that they are suboptimal compared to uniform random points. This is in contrast to the approximation of Sobolev functions and resolves an open question raised in the context of a possible low discrepancy construction on the two-dimensional sphere
An ICT architecture for enabling ancillary services in Distributed Renewable Energy Sources based on the SGAM framework
No full textSmart Grids are electrical grids that require a decentralised way of controlling electric power conditioning and thereby control the production and distribution of energy. Yet, the integration of Distributed Renewable Energy Sources (DRESs) in the Smart Grid introduces new challenges with regards to electrical grid balancing and storing of electrical energy, as well as additional monetary costs. Furthermore, the future smart grid also has to take over the provision of Ancillary Services (ASs). In this paper, a distributed ICT infrastructure to solve such challenges, specifically related to ASs in future Smart Grids, is described. The proposed infrastructure is developed on the basis of the Smart Grid Architecture Model (SGAM) framework, which is defined by the European Commission in Smart Grid Mandate M/490. A testbed that provides a flexible, secure, and low-cost version of this architecture, illustrating the separation of systems and responsibilities, and supporting both emulated DRESs and real hardware has been developed. The resulting system supports the integration of a variety of DRESs with a secure two-way communication channel between the monitoring and controlling components. It assists in the analysis of various inter-operabilities and in the verification of eventual system designs. To validate the system design, the mapping of the proposed architecture to the testbed is presented. Further work will help improve the architecture in two directions; first, by investigating specific-purpose use cases, instantiated using this more generic framework; and second, by investigating the effects a realistic number and variety of connected devices within different grid configurations has on the testbed infrastructure
The Myth of Responsibility: Colonial Cruelties and Silence in German Political Discourse
No full textGermany is considered a role model for dealing with past mass atrocities. In particular, the social reappraisal of the Holocaust is emblematic of this. However, when considering the genocide on the Herero and Nama in present-day Namibia, it is puzzling that an official recognition was only pronounced after almost 120 years, in May 2021. For a long time, silence surrounded this colonial cruelty in German political discourse. Although the discourse on German responsibility toward Namibia emerged after the end of World War II, it initially appeared detached from the genocide. That silence on colonial atrocities is to be considered a cruelty itself. Studies on silence have been expanding and becoming richer. Building on these works, the paper sets two goals: First, it advances the theorization of silence by producing a new typology, which is then integrated into discourse-bound identity theory. Second, it applies this theory to the analysis of the silencing and later acknowledging of the genocide on the Herero and Nama by German political elites. To this end, Bundestag debates, official documents, and statements by relevant political actors are analyzed in the period from 1980 to 2021. The results reveal the dynamics between hegemonic and counter-hegemonic discursive formations, how those are shifting in a period of 40 years, and what role silence plays in it. Beyond our emphasis on the genocide on the Herero and Nama, our findings might benefit future studies as the approach proposed in this paper can make silence a tangible research object for global studies
A Composite Syntactic-Semantic Interpretable Text Entailment Approach Exploring Commonsense Knowledge Graphs
No full textNatural Language Processing has an important role in Artificial Intelligence for easing human-machine interaction. Processing human language, though, poses many challenges, among which is the semantics-related phenomenon known as language variability, the fact that the same thing can be said in several ways. NLP applications' inputs and outputs can be expressed in different forms, whose equivalence can be verified through inference. The textual entailment paradigm was established to enable the creation of a unifying framework for applied inference, providing a means of delivering other NLP task from handling inference issues in an ad-hoc manner, using instead the outputs of an inference-dedicated mechanism.
Text entailment, the task of determining whether a piece of text logically follows from another piece of text, involves different scenarios, which can range from a simple syntactic variation to more complex semantic relationships between sentences. However, most approaches try a one-size-fits-all solution that usually favors some scenario to the detriment of another. The commonsense world knowledge necessary to support more complex inferences is also usually employed in a limited way, with most approaches sticking to shallow semantic information, leaving more elaborate semantic relationships aside. Furthermore, most systems still work as a "black box", providing a yes/no answer that does not explain the underlying reasoning process.
This thesis aims at addressing these issues by proposing a composite interpretable approach for recognizing text entailment where the entailment pair is analyzed so the most relevant phenomenon is detected and the suitable method can be used to solve it. Syntactic variations are dealt with through the analysis of the sentences' syntactic structures, and semantic relationships are detected with the aid of a knowledge graph built from natural language dictionary definitions. Also, if a semantic matching is involved, the answer is made interpretable through the generation of natural language justifications that explain the semantic relationship between the pieces of text. The result is the XTE - Explainable Text Entailment - a system that outperforms well-established tools based on single-technique entailment algorithms, and that also gives an important step towards Explainable AI, allowing the inference model interpretation, making the semantic reasoning process explicit and understandable
Essays on current topics in employee entrepreneurial behaviors and attitudes
No full textA firm's entrepreneurial orientation (EO) is its propensity to act proactively, innovate, take risks, and engage in competitive and autonomous behaviors. Prior research shows that EO is an im-portant factor for new ventures to overcome barriers to survival and fostering growth, measured by annual sales and employment growth rates. In particular, individual-level EO (IEO) is an important driver of a firm’s EO. The firm’s ability to exploit opportunities appearing in the mar-ket and to achieve superior performance depends on the employees’ skills and experiences to act and think entrepreneurially. The main objective of this dissertation is to investigate how and when employees engage in entrepreneurial behaviors at work. Building on three essays, this dissertation takes an interdisciplinary approach to employee entrepreneurial behaviors in new ventures, encompassing both entrepreneurship and gamification research. The first main contri-bution proposed in this field is a more nuanced understanding of how employee entrepreneurial behaviors help young firms cope with growth-related, organization-transforming challenges (i.e., changes in organizational culture that accompany growth, the introduction of hierarchical structures, and the formalization of processes). When new ventures grow, employees’ IEO tends to manifest in introducing technological innovations and business improvements rather than in actions related to risk-taking. Second, this dissertation reveals the relevance of self-efficacy for entrepreneurial behaviors and explores how gamification can enhance employee entrepreneurial behaviors in new ventures. Based on these findings, this dissertation contributes to EO research by highlighting the role of IEO as a building block for EO pervasiveness. This research further develops our knowledge on the use of gamification in new ventures. This cu-mulative dissertation is structured as follows. Part A is an introduction to the study of entrepre-neurial behaviors. Part B contains the three essays.