Matthias Großmann

Learn More
In this paper, we address the data management aspect of large-scale pervasive computing systems. We aim at building an infrastructure that simultaneously supports many kinds of context-aware applications, ranging from room level up to nation level. This all-embracing approach gives rise to synergetic benefits like data reuse and sensor sharing. We identify(More)
Meta data - data about data - improves the value of the operational data by giving applications and users additional information on the data's origin, its precision or staleness. We outline the benefits of modeling meta data in context models: it can be used for resource finding, enhanced data selection, trust and data quality issues and sensor fusion. We(More)
In order to allow blind people independent navigation in unknown areas, we have developed a navigation system that seamlessly integrates both static maps and dynamic location-based textual information from a variety of sources. Each information source requires a different kind of acquisition technique. The acquired information is integrated by a context(More)
Rule-based context reasoning is an expressive way to define situations, which are crucial for the implementation of many context-aware applications. Along the scenario of the Conference Guard application we show how this reasoning can be done both by leveraging an efficient context management (realized by the Nexus platform) and by a generic rule based(More)
Context-aware applications rely on models of the physical world. Within the Nexus project, we envision a World Wide Space which provides the conceptual and technological framework for integrating and sharing such context models in an open, global platform of context providers. In our ongoing research we tackle important challenges in such a platform(More)
The management of mobile objects like cars, persons, or workpieces in a factory is an important task in many context-aware environments. So far, most solutions can either cope with many small objects (few properties) or with a limited number of complex objects in a centralized way. In this paper, we face the challenge of managing a large number of bulky(More)
Location-based services (LBS) have gained tremendous popularity with millions of simultaneous users daily. LBS handle very large data volumes and face enormous query loads. Both the data and the queries possess high locality: spatial data is distributed very unevenly around the globe, query load is different throughout the day, and users often search for(More)
The main in-vivo metabolite of amiodarone, N-desethylamiodarone (DEAM), possesses clinically relevant class-III antiarrhythmic and vasodilator activities. Vasodilation by DEAM is endothelium dependent and involves a sustained and biphasic increase in cytosolic free Ca2+ concentration ([Ca2+]i). The aims of this study were to explore the mechanisms mediating(More)
OBJECTIVES Recent studies suggest that stimulation of beta-adrenergic receptors results in both endothelium-dependent and endothelium-independent venodilation, but results of former studies are inconsistent. This study was designed to elucidate the underlying mechanisms of isoproterenol (INN, isoprenaline)-induced venodilation by investigation of dorsal(More)