Hedda Rahel Schmidtke

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Smart phones have become a powerful platform for wearable context recognition. We present a service-based recognition architecture which creates an evolving classification system using feedback from the user community. The approach utilizes classifiers based on fuzzy inference systems which use live annotation to personalize the classifier instance on the(More)
Wireless Sensing and Radio Identification systems have undergone many innovations during the past years. This has led to short product lifetimes for both software and hardware compared to classical industries. However, especially industries dealing with long-term support of products, e.g. of industrial machinery, and product lifetime of 40+ years may(More)
This paper researches the potential of a novel ball switch as a wearable vibration sensor for activity recognition. The ball switch is available as a commercial, off-the-shelf sensor and is unique among such sensors due to its miniaturized design and the low mass of the ball. We present a detailed analysis of the physical properties of the sensor as well as(More)
A local spatial context is an area currently under consideration in a spatial reasoning process. The boundary between this area and the surrounding space together with the spatial granularity of the representation separates what is spatially relevant from what is irrelevant at a given time. The approach discussed in this article differs from other(More)
In this paper, we discuss the benefits of context prediction for an industrial application in open cast mining. The goal of context prediction is not only to recognize the current context, but also to predict the future context. Context prediction enables a system to become truly proactive. For industrial applications, this can entail concrete monetary(More)
In mobile and ubiquitous computing, there is a strong need for supporting different users with different interests, needs, and demands. Activity recognition systems for context aware computing applications usually employ highly optimized off-line learning methods. In such systems, a new classifier can only be added if the whole recognition system is(More)
Intelligent Environments are currently implemented with standard WSN technologies using conventional connection-based communications. However, connection-based communications may impede progress towards IE scenarios involving high mobility or massive amounts of sensor nodes. We present a novel approach based on collective transmission for item level tagging(More)