Doctoral Thesis
Refine
Year of publication
Institute
- Fachbereich Medizintechnik und Technomathematik (27)
- IfB - Institut für Bioengineering (20)
- Fachbereich Energietechnik (10)
- Fachbereich Luft- und Raumfahrttechnik (10)
- Fachbereich Bauingenieurwesen (6)
- Fachbereich Elektrotechnik und Informationstechnik (6)
- Fachbereich Wirtschaftswissenschaften (5)
- INB - Institut für Nano- und Biotechnologien (4)
- Fachbereich Chemie und Biotechnologie (3)
- Nowum-Energy (3)
Has Fulltext
- no (79)
Language
- German (46)
- English (30)
- Multiple languages (2)
- Russian (1)
Document Type
- Doctoral Thesis (79) (remove)
Keywords
- 3. EU Legislativpaket (1)
- Aachen (1)
- CCD-Bildwandler (1)
- Choleratoxin B (1)
- Combustion (1)
- Datenschutz (1)
- Datenschutz-Management (1)
- Deutschland (1)
- Dreidimensionale Bildverarbeitung (1)
- EU-Datenschutz-Grundverordnung (1)
- Efficiency side-effects (1)
- Effizienz (1)
- Energiewirtschaft (1)
- Geschichte (1)
- Hydrogen (1)
- Hypothesentests (1)
- Klassifikator <Informatik> (1)
- Kohlefeuerung (1)
- Kunstmarkt (1)
- Low NOx (1)
- Low emission (1)
- Management (1)
- Objekterkennung (1)
- Ownership Unbundling (1)
- Rebound effect (1)
- Reduktion <Chemie> (1)
- Referenzmodelle (1)
- Resource-optimization (1)
- Rohrreaktor (1)
- Social Media (1)
- Socio-economics (1)
- Stickstoffoxide (1)
- Stromnetz (1)
- Trinkwassersicherheit (1)
- Unternehmensstrukturen (1)
- Vergleich von Experimenten (1)
- Vorverarbeitung (1)
- Wirbelschichtfeuerung (1)
- cholera toxin B (1)
- drinking water safety (1)
- efficiency (1)
- magnetic frequency mixing technique (1)
- testing hypotheses (1)
- Übertragungsnetz (1)
Soziale Netzwerke sind aus dem Alltag nicht wegzudenken. Es vergeht keine Sekunde, in der nicht abertausende Status-Updates, Kommentare und Nachrichten rund um den Globus versendet werden. Die Stellung als Informations- und Kommunikationsmedium macht die Betreiber solcher Plattformen - zahlreichen Skandalen zum Trotz - zu den Internetgiganten unserer Zeit. Insoweit ist es nicht verwunderlich, dass die Datenschutz-Grundverordnung (DSGVO) auch und gerade mit dem Ziel angetreten ist, soziale Netzwerke zu regulieren.
Die datenschutzrechtliche Diskussion fokussierte sich vor allem auf die Betreiber von sozialen Netzwerken. Unter welchen Umständen welches Recht auf wen Anwendung findet, wer für welche Tätigkeiten verantwortlich ist, und unter welchen Bedingungen eine Verarbeitung rechtmäßig ist, wurde bislang nur pauschal beantwortet. Bei Web 2.0-Plattformen wirkt jedoch eine Vielzahl von Beteiligten zusammen, bei denen Art der Verarbeitung, verfolgte Zwecke und mögliche Rechtsgrundlagen divergieren. Dies macht eine sorgfältige Differenzierung notwendig. Das vorliegende Werk analysiert die Handlungen von Netzwerkbetreibern, Fansite-Betreibern und Nutzern in sozialen Netzwerken und zeigt gleichermaßen Voraussetzungen wie praxistaugliche Lösungen für eine datenschutzkonforme Datenverarbeitung in Hinblick auf alle Beteiligten unter der DSGVO auf.
Schwerpunkte sind die Anwendbarkeit der DSGVO, der Umfang der Verantwortlichkeit der einzelnen Akteure und die Rechtmäßigkeit der Verarbeitung. Daneben werden auch jene Besonderheiten der DSGVO, die spezifische Relevanz für soziale Netzwerke entfalten, ausführlich behandelt. Hierzu zählt etwa das Haushaltsprivileg, die Verarbeitung "sensibler" Daten, das Kopplungsverbot, das Recht auf Datenübertragbarkeit, Privacy by Default oder das vielzitierte "Recht auf Vergessenwerden".
Entwicklung eines Prototypen zur Prognose von Frühgeburten : ein biomedizintechnischer Ansatz
(2012)
This thesis introduces the Integrated Emitter Turn-Off (IETO) Thyristor as a new high-power device. Known state-of-the-art research activities like the Dual GCT, the ETO thyristor and the ICT were presented and critically reviewed. A comparison with commercialized solutions identifies the pros and cons of each type of device family. Based on this analysis, the IETO structure is proposed, covering most benefits of each device class. In particular the combination of a MOS-assisted turn-off with a thyristor-based device allows a voltage-controlled MOS switching and the low on-state voltage of the thyristors. The following synthesis of an IETO device stands on a three-dimensional field of optimization spanned by electric, mechanical and thermal aspects. From an electric point of view, the lowest possible parasitic inductance and resistance within the commutation path are optimization criteria. The mechanical construction has to withstand the required contact pressure of multiple kilo Newtons. Finally, thermal borders limit the maximum average current of the device. FEM simulations covering these three aspects are performed for several design proposals. An IETO prototype is constructed and measurements on various test benches attest thermal, mechanical and electric performance. A local decoupling of the external driver stage and the presspack housing is presented by a cable connection. This separation enables a thermal and mechanical independence, which is advantageous in terms of vibrations and thermal cycles including increased reliability. The electric pulse performance of the prototype device is a factor of 3.1 above today''s solutions. In single-pulse measurements, a current up to 1600 A was successfully turned off at 115°C with an active silicon area of 823 mm². One reason for this increased turn-off capability is the extremely low-inductive construction. Additional functionality of the IETO thyristor like over-current self-protection and defined short-circuit failure state are successfully verified.
Biodiversity and the coexistence of species have puzzled and fascinated biologists since decades and is a hotspot in todays’ natural sciences. Preserving this biodiversity is a great challenge as habitats and environments underlying tremendous changes like climate change and the loss of natural habitats, which are mainly due to anthropogenic influences. The coexistence of numerous species even in homogeneous environments is a stunning feature of natural communities and has been summarized under the term ‘paradox of plankton’. Up to now, there are several mechanisms discussed, which may contribute to local and global diversity of organisms. Several interspecific trade offs have been identified maintaining the coexistence of species like their abilities regarding competition and predator avoidance, their capability to disperse in space and time, and their ability to exploit variable resources. Further, micro-evolutionary dynamics supporting the coexistence of species have been added to our knowledge, and deriving from theoretical deterministic models, non-linear dynamics which describe the temporal fluctuation of abundances of organisms. Whereas competition and predation seem to be clue structural elements within interacting organisms, the intrinsic dynamic behavior – by means of temporal changes in abundance - plays an important role regarding coexistence within a community. The present work sheds light on different factors affecting the coexistence of species using experimental microbial model systems consisting of a bacterivorous ciliate as the predator and two bacteria strains as prey organism. Additionally, another experimental setup consisting of two up to five bacteria species competing for one limiting resource was investigated. Highly controllable chemostat systems were established to exclude extrinsic disturbances. According to theoretical analyses I was able to show - experimentally and theoretically - that phenotypic plasticity of one species within a microbial one-predator-two-prey food web enlarges the range of possible coexistence of all species under different dynamic conditions, compared to a food web without phenotypic plasticity. This was accompanied by non-linear (chaotic) population dynamics within all experimental systems showing phenotypic plasticity. The experiments on the interplay of competition, predation and invasion showed that all aspects have an influence on species coexistence. Under undisturbed controlled conditions all aspects were analyzed in detail and in combination. Populations showed oscillations which were shown by quasi-chaotic attractors in phase space diagrams. Competition experiments with two up to five bacteria species competing for one limiting resource showed that all organisms were able to coexist which was mediated by species oscillations entering a regime of chaos. Besides that fact it was found, that the productivity (biomass) as well as the total cell numbers – under the same nutrition supply – increased by an increasing number of species in the experimental systems. Up to now, the occurrence of non-linear dynamics in well controlled experimental studies has been recognized several times and this phenomenon seemed to be more common in natural systems than generally assumed.