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In the modeling context, non-linearities and uncertainty go hand in hand. In fact, the utility function's curvature determines the degree of risk-aversion. This concept is exploited in the first article of this thesis, which incorporates uncertainty into a small-scale DSGE model. More specifically, this is done by a second-order approximation, while carrying out the derivation in great detail and carefully discussing the more formal aspects. Moreover, the consequences of this method are discussed when calibrating the equilibrium condition. The second article of the thesis considers the essential model part of the first paper and focuses on the (forward-looking) data needed to meet the model's requirements. A large number of uncertainty measures are utilized to explain a possible approximation bias. The last article keeps to the same topic but uses statistical distributions instead of actual data. In addition, theoretical (model) and calibrated (data) parameters are used to produce more general statements. In this way, several relationships are revealed with regard to a biased interpretation of this class of models. In this dissertation, the respective approaches are explained in full detail and also how they build on each other.
In summary, the question remains whether the exact interpretation of model equations should play a role in macroeconomics. If we answer this positively, this work shows to what extent the practical use can lead to biased results.
Auf der Grundlage einer Fragebogenstudie wurden unterschiedliche Elemente eines förderlichen Umgangs mit Gesundheitsinformationen betrachtet und ihre Zusammenhänge mit personspezifischen Merkmalen analysiert. Als zentrale Aspekte der Informationsprozesse wurden die drei Elemente Gesundheitsinformationskompetenz, Gesundheitsinteresse und gesundheitsspezifische Informationsgewohnheiten konzeptuell voneinander getrennt. Auf der Basis des bisherigen Forschungsstands wurde zunächst ein theoretisches Modell des Umgangs mit Gesundheitsinformationen entwickelt, das die Bedeutung der Kompetenz und des Interesses für gesundheitsbezogene Informationsgewohnheiten hervorhebt, individuelle Ausprägungen dieser drei Elemente mit soziodemografischen Faktoren, Persönlichkeitseigenschaften, Überzeugungen und dem Gesundheitszustand in Beziehung setzt sowie Verbindungen zu gesundheitsrelevanten Verhaltensweisen beschreibt. Dieses Modell wurde anschließend an einer Stichprobe von 352 Berufsschülerinnen und -schülern aus drei Berufsbereichen (Wirtschaft/Verwaltung, Technik und Gesundheit) empirisch überprüft. Über multiple Regressionsanalysen wurden bedeutsame Prädiktoren für die drei Hauptelemente Kompetenz, Interesse und Informationsgewohnheiten identifiziert, über logistische Regressionen und Korrelationen ihre Zusammenhänge mit dem Gesundheitsverhalten überprüft. Darüber hinaus wurden lineare Strukturgleichungsmodelle zur Vorhersage des Informationsverhaltens entwickelt. Die Ergebnisse bestätigen die konzeptionelle Trennung der drei Faktoren, die jeweils mit unterschiedlichen Prädiktoren verbunden waren. Auf der Basis der Befunde werden Ansatzpunkte für die weitere Forschung und die Förderung eines kompetenten Umgangs mit Gesundheitsinformationen diskutiert.
Although gravitropism forces trees to grow vertically, stems have shown to prefer specific orientations. Apart from wind deforming the tree shape, lateral light can result in prevailing inclination directions. In recent years a species dependent interaction between gravitropism and phototropism, resulting in trunks leaning down-slope, has been confirmed, but a terrestrial investigation of such factors is limited to small scale surveys. ALS offers the opportunity to investigate trees remotely. This study shall clarify whether ALS detected tree trunks can be used to identify prevailing trunk inclinations. In particular, the effect of topography, wind, soil properties and scan direction are investigated empirically using linear regression models. 299.000 significantly inclined stems were investigated. Species-specific prevailing trunk orientations could be observed. About 58% of the inclination and 19% of the orientation could be explained by the linear models, while the tree species, tree height, aspect and slope could be identified as significant factors. The models indicate that deciduous trees tend to lean down-slope, while conifers tend to lean leeward. This study has shown that ALS is suitable to investigate the trunk orientation on larger scales. It provides empirical evidence for the effect of phototropism and wind on the trunk orientation.
Systemische Resilienz
(2020)
This work deals with the current support landscape for Social Entrepreneurship (SE) in the DACH region. It provides answers to the questions of which actors support SE, how and why they do so, and which social ventures are supported. In addition, there is a focus on the motives for supporting SE as well as the decision-making process while selecting social ventures. In both cases, it is examined whether certain characteristics of the decision-maker and the organization influence the weighting of motives and decision-making criteria. More precise, the gender of the decision-maker as well as the kind of support by the organization is analyzed. The concrete examples of foundations and venture philanthropy organizations (VPOs) will give a deeper look at the SE support motives and decision-making behavior. In a quantitative empirical data collection, by means of an online survey, decision-makers from SE supporting organizations in the DACH region were asked to participate in a conjoint experiment and to fill in a questionnaire. The results illustrate a positive development of the SE support landscape in the German-speaking area as well as the heterogeneity of the organizational types, the financial and non-financial support instruments and the supported social ventures. Regarding the motives for SE-support, a general endeavor to change and to create an impact has proven to be particularly important at the organizational and the individual level. At the individual level female and male decision-makers have subtle differences in their motives to promote SE. Robustness checks by analyzing certain subsamples provide information about that. Individuals from foundations and VPOs, on the other hand, hardly differ from each other, even though here individuals with a rather social background face individuals with a business background. At the organizational level crucial differences can be identified for the motives, depending on the nature of the organization's support, and again comparing foundations with VPOs. Especially for the motives 'financial interests', 'reputation' and 'employee development' there are big differences between the considered groups. Eventually, by means of cluster analysis and still with respect to the support motives, two types of decision-makers could be determined on both the individual and the organizational level.
In terms of the decision-making behavior, and the weighting of certain decision-making criteria respectively, it has emerged that it is worthwhile having a closer look: The 'importance of the social problem' and the 'authenticity of the start-up team' are consistently the two most important criteria when it comes to selecting social ventures for supporting them. However, comparing male and female decision-makers, foundations and VPOs, as well as the two groups of financially and non-financially supporting organizations, there are certain specifics which are highly relevant for SE practice. Here as well a cluster analysis uncovered patterns of criteria weighting by identifying three different types of decision-makers.
Das DIAMANT-Modell wurde im Rahmen des BMBF-geförderten Projekts „Prozessorientierte Entwicklung von Managementinstrumenten für Forschungsdaten im Lebenszyklus“ (PODMAN) entwickelt. Das grundsätzliche Ziel des Modells besteht darin, Hochschulen und außeruniversitäre Forschungseinrichtungen zu befähigen, eine integrierte Informationsarchitektur für die optimierte Bereitstellung und Weiterentwicklung von Forschungsdatenmanagement (FDM)-Technologien und -services aufzubauen und zu pflegen, sodass die Forschenden ihre Forschungsdatensätze zu „hochkarätigen Diamanten“ schleifen können. Das DIAMANTModell besteht zum einen aus dem FDM-Referenzprozess, der – angelehnt an die ARIS-Prozessmodellierung – den gesamten FDM-Prozess und die zugehörigen Akteur*innen darstellt und ihren Grad der Beteiligung / Verantwortung an einem FDM-Service benennt. Der FDM-Referenzprozess sieht die Etablierung einer zentralen FDM-Steuerungseinheit vor, die den Informationsfluss zwischen allen am FDM beteiligten Organisationseinheiten steuert. Ein weiterer Bestandteil des DIAMANT-Modells ist die FDM-Kompetenzmatrix, die sich aus dem FDM-Referenzprozess ableitet. Sie dient der IST- / SOLL-Analyse, um den Referenzprozess auf die eigene Institution übertragen zu können. Abgeleitet wurde auch ein Beschreibungsmodell für FDMServices, um einen FDM-Service- /-Anforderungskatalog zu entwickeln und institutsspezifisch fortzuschreiben. Letzter Teil des DIAMANT-Modells sind Empfehlungen, welche Aspekte hinsichtlich der Personalführung und des Organisationsmanagements bei der Implementierung der FDM-Servicelandschaft berücksichtigt werden sollten.
Hypothalamic-pituitary-adrenal (HPA) axis-related genetic variants influence the stress response
(2020)
The physiological stress system includes the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary system (SAM). Parameters representing these systems such as cortisol, blood pressure or heart rate define the physiological reaction in response to a stressor. The main objective of the studies described in this thesis was to understand the role of the HPA-related genetic factors in these two systems. Genetic factors represent one of the components causing individual variations in physiological stress parameters. Five genes involved in the functioning of the HPA axis regarding stress responses are examined in this thesis. They are: corticotropin-releasing hormone (CRH), the glucocorticoid receptor (GR), the mineralocorticoid receptor (MR), the 5-hydroxytryptamine-transporter-linked polymorphic region (5-HTTLPR) in the serotonin transporter (5-HTT) and the brain-derived neurotrophic factor (BDNF) gene. Two hundred thirty-two healthy participants were genotyped. The influence of genetic factors on physiological parameters, such as post-awakening cortisol and blood pressure was assessed, as well as the influence of genetic factors on stress reactivity in response to a socially evaluated cold pressor test (SeCPT). Three studies tested the HPA-related genes each on three different levels. The first study examined the influences of genotypes and haplotypes of these five genes on physiological as well as psychological stress indicators (Chapter 2). The second study examined the effects of GR variants (genotypes and haplotypes) and promoter methylation level on both the SAM system and the HPA axis stress reactivity (Chapter 3). The third study comprised the characterization of CRH promoter haplotypes in an in-vitro study and the association of the CRH promoter with stress indicators in vivo (Chapter 4).
In this thesis we study structure-preserving model reduction methods for the efficient and reliable approximation of dynamical systems. A major focus is the approximation of a nonlinear flow problem on networks, which can, e.g., be used to describe gas network systems. Our proposed approximation framework guarantees so-called port-Hamiltonian structure and is general enough to be realizable by projection-based model order reduction combined with complexity reduction. We divide the discussion of the flow problem into two parts, one concerned with the linear damped wave equation and the other one with the general nonlinear flow problem on networks.
The study around the linear damped wave equation relies on a Galerkin framework, which allows for convenient network generalizations. Notable contributions of this part are the profound analysis of the algebraic setting after space-discretization in relation to the infinite dimensional setting and its implications for model reduction. In particular, this includes the discussion of differential-algebraic structures associated to the network-character of our problem and the derivation of compatibility conditions related to fundamental physical properties. Amongst the different model reduction techniques, we consider the moment matching method to be a particularly well-suited choice in our framework.
The Galerkin framework is then appropriately extended to our general nonlinear flow problem. Crucial supplementary concepts are required for the analysis, such as the partial Legendre transform and a more careful discussion of the underlying energy-based modeling. The preservation of the port-Hamiltonian structure after the model-order- and complexity-reduction-step represents a major focus of this work. Similar as in the analysis of the model order reduction, compatibility conditions play a crucial role in the analysis of our complexity reduction, which relies on a quadrature-type ansatz. Furthermore, energy-stable time-discretization schemes are derived for our port-Hamiltonian approximations, as structure-preserving methods from literature are not applicable due to our rather unconventional parametrization of the solution.
Apart from the port-Hamiltonian approximation of the flow problem, another topic of this thesis is the derivation of a new extension of moment matching methods from linear systems to quadratic-bilinear systems. Most system-theoretic reduction methods for nonlinear systems rely on multivariate frequency representations. Our approach instead uses univariate frequency representations tailored towards user-defined families of inputs. Then moment matching corresponds to a one-dimensional interpolation problem rather than to a multi-dimensional interpolation as for the multivariate approaches, i.e., it involves fewer interpolation frequencies to be chosen. The notion of signal-generator-driven systems, variational expansions of the resulting autonomous systems as well as the derivation of convenient tensor-structured approximation conditions are the main ingredients of this part. Notably, our approach allows for the incorporation of general input relations in the state equations, not only affine-linear ones as in existing system-theoretic methods.
This dissertation details how Zeami (ca. 1363 - ca.1443) understood his adoption of the heavenly woman dance within the historical conditions of the Muromachi period. He adopted the dance based on performances by the Ōmi troupe player Inuō in order to expand his own troupe’s repertoire to include a divinely powerful, feminine character. In the first chapter, I show how Zeami, informed by his success as a sexualized child in the service of the political elite (chigo), understood the relationship between performer and audience in gendered terms. In his treatises, he describes how a player must create a complementary relationship between patron and performer (feminine/masculine or yin/yang) that escalates to an ecstasy of successful communication between the two poles, resembling sexual union. Next, I look at how Zeami perceived Inuō’s relationships with patrons, the daimyo Sasaki Dōyo in chapter two and shogun Ashikaga Yoshimitsu in chapter three. Inuō was influenced by Dōyo’s masculine penchant for powerful, awe-inspiring art, but Zeami also recognized that Inuō was able to complement Dōyo’s masculinity with feminine elegance (kakari and yūgen). In his relationship with Yoshimitsu, Inuō used the performance of subversion, both in his public persona and in the aesthetic of his performances, to maintain a rebellious reputation appropriate within the climate of conflict among the martial elite. His play “Aoi no ue” draws on the aristocratic literary tradition of the Genji monogatari, giving Yoshimitsu the role of Prince Genji and confronting him with the consequences of betrayal in the form of a demonic, because jilted, Lady Rokujō. This performance challenged Zeami’s early notion that the extreme masculinity of demons and elegant femininity as exemplified by the aristocracy must be kept separate in character creation. In the fourth chapter, I show how Zeami also combined dominance (masculinity) and submission (femininity) in the corporal capacity of a single player when he adopted the heavenly woman dance. The heavenly woman dance thus complemented not only the masculinity of his male patrons with femininity but also the political power of his patrons with another dominant power, which plays featuring the heavenly woman dance label divine rather than masculine.
In der Reaktion auf die Ausbreitung der Covid-19-Pandemie kam es weltweit für viele Menschen zum Bruch sozialer und räumlicher Routinen. In Deutschland haben die Landesregierungen die führende Rolle beim Versuch übernommen, durch Verfügungen und Verordnungen die weitere Ausbreitung der Pandemie einzudämmen. In diesem Kontext hat die Art und Weise wie Gesetze und Regeln Alltagsräume durchdringen für viele Menschen eine neue (unmittelbar erlebbare) Dimension angenommen. Ziel dieses Beitrags ist es, mit einem Fokus auf die getroffenen Maßnahmen der saarländischen Landesregierung diesbezüglich eine lokale Perspektive zu entwickeln. Durch die qualitative Methode der Autofotographie werden dabei individuelle Sichtweisen auf das zugrundeliegende Wechselspiel von Recht, Raum und Gesellschaft in den Vordergrund der Analyse gestellt. Durch den Blick auf sozialräumliche Zusammenhänge werden so die Auswirkungen der getroffenen Maßnahmen hinterfragt.