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Konferenzveröffentlichung
Controlled magnetic devices in power electronic applications
(IEEE, 2017)
Almost all power electronic converters require magnetic devices and some properties of the converters can be controlled with magnetics. New magnetic materials enable implementation of magnetic control of converters also in high switching frequency applications. The presented paper gives an overview about controllability of magnetic devices in theory and practice, simulation approaches and examples. The focus is on electrically controllable magnetic devices. This means that an additional control winding is wound on ...
Dissertation
Large-scale modeling of bacterial contamination in rivers, to support the global assessment of pollutant concentrations in rivers
(2017-02-06)
Die räumliche Verteilung und der Zustand der Wasserqualität sind in vielen Teilen der Erde nicht bekannt und das, obwohl gesundes Leben und Wohlergehen auf Frischwasserressourcen mit einer guten bis exzellenten Wasserqualität beruhen. Heute sind 5,7% aller Behinderungen und Krankheiten sowie 4% aller Sterbefälle auf unsicheren Wasserzugang, mangelhafte sanitäre Anlagen und unzureichende persönliche und Haushaltshygiene zurückzuführen.
Im Rahmen dieser Arbeit wird mit dem großskaligen Wasserqualitätsmodell WorldQual ...
Dissertation
Self-Healing in Autonomous Robot Teams
(2017-05-24)
Today, robots are used in nearly every type of automated manufacturing and assembly process. Robot installations typically apply static actuator systems in clearly structured environments. These systems show impressive abilities in speed and accuracy for repetitive manipulation tasks. Future automation applications, however, require an increasing level of flexibility, where classical systems reach their physical limits. As a reaction, robots become mobile, intelligent and cooperative. These new characteristics, ...
Technischer Report
Software Stories Guide
(2017-07-31)
Software Stories are a simple graphical notation for requirements analysis and design in agile software projects. Software Stories are based on example scenarios. Example scenarios facilitate the communication between lay people or domain experts and software experts.
Dissertation
Transfer characteristics of white light interferometers and confocal microscopes
(2017-11-23)
Optical profilers present significant advantages in comparison with stylus profilometry and scanning probe microscopy due to their non-contacting technique and their ability to scan the entire measurement field simultaneously. However, optical profilers suffer from different systematical artifacts. The dissertation investigates the transfer characteristics of optical profilometers, namely white light interferometers and confocal microscopes.
In white light interferometry dispersion in the optical system leads to ...
Dissertation
Load Reducing Control for Wind Turbines: Load Estimation and Higher Level Controller Tuning based on Disturbance Spectra and Linear Models
(2017-05-08)
The aim of this work is to demonstrate an efficient and pragmatic approach for design and optimization of load reducing controllers for wind turbines. Load reducing control means that, besides the classical rotor speed control loop, load or oscillation signals are included as additional input signals into the controller. Thereby, a multiple-input-multiple-output (MIMO) control design problem arises.
While the basic concepts of load reducing control and the achievable load reductions are essentially known from ...
Dissertation
Supporting Researchers: Analyzing the Scholarly Publication Life Cycle and Social Bookmarking Systems
(2017-04-19)
Researchers must face the exponential growth of the body of available scholarly literature, which makes it ever harder to keep track with one’s own community, especially for newcomers. In this thesis, we explore different means of supporting researchers with that task. For this purpose, we follow two approaches: We provide analyses of research communities and of researchers’ interactions through data that can be obtained from the phases in the life cycle of scholarly publications (creation, dissemination, usage, and ...
Dissertation
An algorithmic approach to increase the context prediction accuracy by utilizing multiple context sources
(2017-09-06)
Heutzutage sind wir umgeben von technischen System und Geräten die unser alltägliches Leben unterstützen und vereinfachen sollen. Wir nutzen Mobiltelefone, um überall auf Informationen zugreifen zu können, intelligente Haussteuerungen, um unsere Sicherheit und unseren Wohnkomfort zu steigern und Fahrerassistenzsysteme im Automobil, um unsere Fahrten angenehmer und sicherer zu gestalten. Allerdings erwarten wir oft ein vorausschauendes Verhalten solcher Systeme: das Mobiltelefon soll die Bahnstörung einblenden bevor ...
Dissertation
Experimental Investigation of Augmented Electromagnetic Accelerators
(2017-03-03)
Elektromagnetische Schienenbeschleuniger verwenden elektrische Energie für die Beschleunigung von trägen Massen und erreichen Geschwindigkeiten, die mit konventionellen Beschleunigungstechnologien nur mit hohem Aufwand erreicht werden können. Die einfachste Konfiguration eines solchen Beschleunigers besteht aus zwei Schienen aus leitfähigem Material, die über eine gleitende Strombrücke elektrisch miteinander verbunden sind. Für die Beschleunigung der Strombrücke ist ein großer Strom erforderlich, der einige Mega-Ampere ...
Dissertation
Modellierung von raum-zeitlichen Eigenschaften der Windenergieeinspeisung für wetterdatenbasierte Windleistungssimulationen
(2017-02-08)
This thesis describes statistical and mathematical models for the quantification of today’s and the representation of future characteristics of the wind power generation in time and space.
These models serve particularly for the quantification of the spatial distribution of installed wind power capacities, the calculation of the average hub heights of wind farms, the development of wind energy scenarios, the inserting of wind speed fluctuations into given wind speed time series, the modeling of the intermittent ...