Robert Mertens

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Energy harvesters [1] power energy-autonomous wireless sensor systems by converting ambient environmental energy into electrical energy. Thermoelectric generators (TEG’s) are a suitable compact power supply for both on-the-body and industrial sensors. Due to changing conditions, the generated power and voltage vary. Therefore a power management circuit(More)
Given the exponential growth of videos published on the Internet, mechanisms for clustering, searching, and browsing large numbers of videos have become a major research area. More importantly, there is a demand for event detectors that go beyond the simple finding of objects but rather detect more abstract concepts, such as "feeding an animal" or a(More)
In the current trend toward portable applications, highintegrated inductors are gaining a lot of importance. Using thin-film multilayer or multichip-module-deposition technology, highcircular inductors for RF and microwave applications may be integrated efficiently. Their quality factors may go up to over 100. In this paper, an accurate analytical model for(More)
Currently, two different solutions for filesystems on flash storage exist: Flash Translation Layers in combination with traditional filesystems and log-structured flash file systems. This paper analyzes the weaknesses of both approaches and derives a number of requirements that help avoiding these weaknesses. Finally the basic concept of a tree structured(More)
Vor Beginn der Diluvialzeit, wahrscheinlich im späteren Tertiär, ist die Stammform der beiden europäischenBombina-Arten aus Südostasien nach Mitteleuropa vorgedrungen und hat sich dort zunächst in zwei Lokalrassen, in eine westliche (Bombina „variegata”) und eine östliche (Bombina „bombina”) differenziert. Durch die Glazialzeiten wurden beide voneinander(More)
Recording live lectures has proven to be a fast and efficient way of creating content for e-learning (Lauer & Ottmann, 2002). This content can be used in a number of ways ranging from simply augmenting a lecture to profoundly changing its didactic setting. See (Mertens et al., 2004 a) for an overview. A number of application scenarios aim for replacing the(More)
Vector graphics are an ideal content format for slide based lecture recordings. File sizes can be kept small and graphics can be displayed in superior quality. Information about text and slide objects is stored symbolically which allows texts to be searched and objects on slides to be used interactively, e.g. for navigation purposes. The use of vector(More)