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Data management is a cornerstone for any kind of information system - including the aerospace and aviation sector. In contrast to conventional domains, software development in the avionics domain must adhere to a legally binding certification process, called qualification. The success of the process depends on compliance with international standards, such as DO-178: Software Considerations in Airborne Systems and Equipment Certification. From a software developer's perspective, challenges arise in terms of methods and tools. Techniques that have a potential impact on the deterministic and predictable execution of avionics software are prohibited.
The objective of this thesis' research is to develop a scalable method to realize data-management for multi-variant avionics software under the restrictions and constraints of the domain. Since avionics software faces very long-term life-cycles (up to 75 years), a particular focus is being placed on maintenance and evolution. Based on the insights gained in a semi-structured interview at Airbus Helicopters, industrial established approaches to implement qualified avionics software are assessed at first and compared with respect to strengths and weaknesses for data-management afterwards. As a result, a novel development approach is proposed, combining model-based techniques and product-line technology to derive the source code of highly specific data-management variants, as well as the majority of assets required for the qualification process, from a declarative system specification.
In order to demonstrate the practicability of the approach in industry, a framework is presented that is deployed and applied at Airbus Helicopters to generate qualifiable data-management components for the variants of the NH90 helicopter. The maintainability is shown by means of a domain-specific optimization, in which the model-based and generative approach is used to establish safe memory overlays at compile-time. Key findings reveal a substantially reduced memory footprint (29,1% in case of a real-world scenario), as well as an significantly facilitated implementation process, which would not be accomplishable using conventional methods for software development in the avionics domain.
This paper aims at the documentation of the results of a study dealing with the relationship between in-group and out-group attitudes. The research enquires into the question whether nationalistic, patriotic, and anti-immigration attitudes are only correlated with each other or whether there is a causal relationship. The presentation of the Mplus output together with the correlation and covariance matrices will allow the readers to control the results and, if they want to do it, to test alternative models.
The Linear Ordering problem consists in finding a total ordering of the vertices of a directed graph such that the number of backward arcs, i.e., arcs whose heads precede their tails in the ordering, is minimized. A minimum set of backward arcs corresponds to an optimal solution to the equivalent Feedback Arc Set problem and forms a minimum Cycle Cover.
Linear Ordering and Feedback Arc Set are classic NP-hard optimization problems and have a wide range of applications. Whereas both problems have been studied intensively on dense graphs and tournaments, not much is known about their structure and properties on sparser graphs. There are also only few approximative algorithms that give performance guarantees especially for graphs with bounded vertex degree.
This thesis fills this gap in multiple respects: We establish necessary conditions for a linear ordering (and thereby also for a feedback arc set) to be optimal, which provide new and fine-grained insights into the combinatorial structure of the problem. From these, we derive a framework for polynomial-time algorithms that construct linear orderings which adhere to one or more of these conditions. The analysis of the linear orderings produced by these algorithms is especially tailored to graphs with bounded vertex degrees of three and four and improves on previously known upper bounds. Furthermore, the set of necessary conditions is used to implement exact and fast algorithms for the Linear Ordering problem on sparse graphs. In an experimental evaluation, we finally show that the property-enforcing algorithms produce linear orderings that are very close to the optimum and that the exact representative delivers solutions in a timely manner also in practice.
As an additional benefit, our results can be applied to the Acyclic Subgraph problem, which is the complementary problem to Feedback Arc Set, and provide insights into the dual problem of Feedback Arc Set, the Arc-Disjoint Cycles problem.
Der deutsche Markt für Abschlussprüfungen: Marktstruktur, Regulierungsmaßnahmen und Prüferwechsel
(2018)
Diese Dissertation ist eine empirische Untersuchung über die Entwicklung des deutschen Markts für Abschlussprüfungen in den Jahren 2005 bis 2014. Das Ziel ist es, eine Beurteilung über die Notwendigkeit, die Auswirkungen sowie die Zielerreichung regulatorischer Eingriffe in diesem Zeitraum abzugeben. Dabei folgt die Arbeit einer Dreiteilung. Die Analyse der Marktstruktur soll u. a. über die Notwendigkeit der Einführung rechtlicher Normen Aufschluss geben. Auf Basis der Untersuchung von Regulierungsmaßnahmen werden Auswirkungen sowie die Zielerreichung dieser Normen untersucht. Eine Ereignisstudie zur Kapitalmarktreaktion auf Prüferwechsel soll schließlich die Einschätzung des Kapitalmarkts gegenüber der kontrovers diskutierten Regulierungsmaßnahme einer externen Rotationspflicht aufzeigen. Die methodische Vorgehensweise basiert auf Mehrebenenmodellen. Mit einem Paneldatensatz von 2.636 Beobachtungen (353 Unternehmen) weist die Arbeit eine der umfangreichsten Basisstichproben der deutschen Prüfungsmarktforschung auf. Die Resultate zeigen, dass die Notwendigkeit für regulatorische Eingriffe durch die analysierte Erhöhung der Prüferunabhängigkeit im Untersuchungszeitraum gerechtfertigt werden kann. Hinsichtlich der Auswirkungen ergeben sich ein Anstieg der Prüferhonorare sowie eine Verringerung der Bilanzpolitik. Die Zielerreichung einer Stärkung der Prüferunabhängigkeit sowie einer Erhöhung der Qualität der Abschlussprüfung kann zudem nachgewiesen werden. Zuletzt wird aufgezeigt, dass der Kapitalmarkt negativ auf Prüferwechsel reagiert.
An increasing number of companies report that eco-sustainable initiatives have a positive impact on firms’ economic performance and concurrently allow the combination of social and commercial goals by optimizing environmental and economic decisions simultaneously. These initiatives are considered an integral part of organizational sustainability transformations, which are a special case of multilayered, complex organizational change efforts that relate to environmental, organizational, and individual factors. Institutional logics and information systems (IS) have shown to be two important perspectives from which to explore mechanisms and processes central to organizational sustainability transformations. Institutional logics offer a unique perspective to investigate organizational change for sustainability because they provide a new approach to organizational change that incorporates macro structures, culture, and agency to explain how actions are enabled or constrained. It thus allows for insights into the complex and miscellaneous interplay of external and internal determinants that govern organizational transformation processes towards sustainability. By providing insights into institutional changes of practice and behaviors, an institutional logic perspective allows for a detailed analysis of organizational transformations. Within these change processes, IS have shown to be an efficient and pervasive tool to leverage sustainability by integrating human and technological factors. Since IS have become a key resource for the encouragement of organizational sustainability transformations, adopting an IS perspective allows for an understanding of mechanisms and processes that enable IS to foster sustainability in organizations. Thus, this dissertation draws on four studies by investigateing an institutional logic perspective as well as an IS perspective to explore organizational sustainability transformations and facilitate an in-depth understanding of organizational, human, and technological factors that encourage sustainability in organizational transformations.
The Semantic Web exists for about 20 years by now, but its applicability as well as its presence does not live up to the standards of its original idea. Incorporated Semantic Web Technologies do have an initial barrier to learn and apply, which can discourage many potential users. This leads to less available data overall in addition to decreased data quality.
This work solves parts of the aforementioned problem by supporting idiomatic entry to those Semantic Web Technologies, allowing for "easier" accessibility and usability. Anno4j is a Java library that implements a form of Object-Relational Mapping for RDF data. With its application, RDF data can be created via a mapping by simply instantiating Java objects - an object-oriented programming concept the user is familiar with. On the other side, requesting persisted data is supported by a path-based querying possibility, while other features like transactional behaviour, code generation, and automated validation of input contribute to a more effective, comprehensive, and straightforward usage.
A use-case is provided by the MICO Platform, a centralized software instance that connects autonomous multimedia extractors in a workflow-driven fashion. This leads to a rich metadata background for the inserted multimedia files, enabling them to be used in diverse scenarios as well as unlocking yet hidden semantics. For this task it was necessary to design and implement a metadata model that is able to aggregate and merge the varying extractor results under a common denominator: the MICO Metadata Model.
The results of this work allow the use case to incorporate idiomatic Semantic Web Technologies which are then usable natively by non-Semantic Web experts. Additionally, an increase has been achieved in forms of data integration, synchronisation, integrity and validity, as well as an overall more comprehensive and rich implementation of the multimedia extractors.
#WirSindMehrThemen
(2018)
Der #wirsindmehr steht für die Befürwortung einer pluralistischen Gesellschaft. Nicht nur Gesellschaften, sondern auch sozialwissenschaftliche Themen profitieren von Vielfalt. Um die große Bandbreite dieser Themen wertzuschätzen, trägt diese Ausgabe den Titel „#WirSindMehrThemen“.
Rebecca Gramlich befasst sich anhand des Theaterstücks „Mi Piedra Rosetta“ von J.R. Fernández mit der Frage, wie das Konzept „Aestethics of Acces“ einen Zugang für Gehörlose zum Theater darstellt. Die Frage „Was ist Geld?“ beantwortet Simon Rettenmaier mit Hilfe zweier Geldtheorien von Marcel Mauss und Christoph Türcke. Lena Keicher widmet sich in Ihrer Arbeit der neuen Identitätskonstruktion der Türkei und untersucht die Auswirkungen derer auf die Bezeigungen zur EU.
Inhalt:
Rebecca Gramlich
AESTHETICS OF ACCESS
Taubheit in J.R. Fernández' Mi Piedra Rosetta
Simon Rettenmaier
WAS IST GELD?
Zwei Theorien zu einer Frage
Lena Keicher
TURKEY IS STANDING ON ITS OWN FEET NOW
Wie die neue Identitätskonstruktion der Türkei unter der AKP die Beziehung zur EU beeinflusst
While in some Eastern European countries a wave of colored revolutions challenged existing political orders, Belarus has remained largely untouched by mass protests. In Minsk, the diffusion of democratic ideas leading to the mobilization of population meets a stable authoritarian regime. Nevertheless, the stagnating democratization process cannot be only attributed to the strong authoritarian rule and abuse of power. Indeed, Belarusian president Alexander Lukashenko still enjoys popularity by a large part of the population. Although international observers report that elections in Belarus have never been free and fair, few commentators doubt that Lukashenko would not have won in democratic elections. This evidence suggests that the regime succeeded in building a strong legitimizing basis, which has not been seriously challenged during the last two decades. This paper explores the authoritarian stability in Belarus by looking at the patterns of state ideology. The government effectively spreads state ideology since the early 2000s. Ideology departments have been created in almost all state institutions. The education sector has been affected by the introduction of the compulsory course "The Fundamentals of Belarusian State Ideology" at all universities, and increasing attention to the patriotic education at schools. Based on document analysis, I trace the creation of "ideological vertical" in Belarus and focuse on the issue of ideology in education and youth policy sectors.