Frank Reichenbach

Learn More
− In sensor networks, randomly distributed sensor nodes have to determine its own positions to assign measurements to locations. Due to limited resources of the nodes, resourceaware positioning algorithms are required. In this paper, we present a solution to minimize the positioning error of the “Weighted Centroid Localization” algorithm (WCL) using hop(More)
The Bcl-2 proteins Bax and Bak can permeabilize the outer mitochondrial membrane and commit cells to apoptosis. Pro-survival Bcl-2 proteins control Bax by constant retrotranslocation into the cytosol of healthy cells. The stabilization of cytosolic Bax raises the question whether the functionally redundant but largely mitochondrial Bak shares this level of(More)
Modern sensor networks are deployed in various terrains of interest. As the complexity of their deployed areas is growing, existing geographic routing algorithms are facing challenges. Holes in networks often cause failures in message routing. Energy consumption, scalability, and routing efficiency are also key design challenges. In this paper, we propose a(More)
Localizing sensor nodes is essential due to their random distribution after deployment. To reach a long network lifetime, which strongly depends on the limited energy resources of every node, applied algorithms must be developed with an awareness of computation and communication cost. In this paper we present a new localization method, which places a(More)
Obstacles are but pleasing for many aspects of large real-world sensor networks. Among other things, the presence of obstacles distort the sensor node localization process and might lead to costly routing because of unnecessary detours and/or dead ends. In order to relieve these problems, this paper proposes a distributed obstacle localization algorithm,(More)
The localization process in wireless sensor networks must produce precise positions at minimal requirements. It is hard to comply with these conditions, due to the strong resource limitation of each sensor node. Although numerous algorithms have already been presented, so far there exist neither an extensive simulative comparison of them nor a qualified(More)
In this paper, we describe the optimization of techniques to determine the position of nodes in a wireless sensor network based on the "Coarse Grained Localization" algorithm. The algorithm features very low complexity at sufficient precision thus matching the low resources found in wireless sensor networks. All nodes in a sensor network calculate their(More)
With increasing system complexity and extensive use of computerized control of industrial processes and plants, it is essential to have a systematic approach for identifying failures that can expose people and environment for unacceptable risks. With focus on a drive system used to control a linear motor, the fault tree analysis method is utilized to reveal(More)