Holger Friedrich

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Programming by Demonstration (PbD) is a programming method that allows software developers to add new functionalities to a system by simply showing them in the form of few examples. In the robotics domain it has the potential to reduce the amount of time required for programming and also to make programming more natural. Just imagine the task of assembling(More)
Performance prediction methods can help software architects to identify potential performance problems, such as bottlenecks, in their software systems during the design phase. In such early stages of the software life-cycle, only a little information is available about the system’s implementation and execution environment. However, these details are crucial(More)
Risk stratification of patients with idiopathic dilated cardiomyopathy (IDC) is an epidemiologically relevant question. But the results based on conventional heart rate variability (HRV) analysis are still unsatisfactory. The adjustments within the cardiovascular system incorporate nonlinear and complex mechanisms of information exchange which may have(More)
BACKGROUND Multiple organ dysfunction syndrome (MODS) is the sequential failure of several organ systems after a trigger event, like cardiogenic shock or decompensated heart failure. Mortality is high, up to 70%. Autonomic dysfunction (AD) may substantially contribute to the development of MODS. In cardiology, it has recently been shown that nonlinear(More)
Service robots require interactive programming interfaces that allow users without programming experience to easily instruct the robots. Systems following the Programming by Demonstration (PbD) paradigm that were developed within the last years are getting closer to this goal. However, most of these systems lack the possibility for the user to supervise and(More)
PURPOSE Complex autonomic communication can be assessed by autonomic information flow (AIF) functions. The objective was to evaluate new complexity measures involving physiologically relevant time scales to predict the length of stay (LOS) in the hospital after abdominal aortic surgery (AAS). Our hypothesis was that AAS disrupts AIF, that restoration of AIF(More)
We present a view-based method for steering a robot in a network of positions; this includes navigation along a prerecorded path, but also allows for arbitrary movement of the robot between adjacent positions in the network. The approach uses an upward-looking omnidirectional camera; even a very modest quality of the optical system is sufficient, since all(More)
In this paper, we propose the extension of a view-based method for autonomous track following formerly introduced as Optical Rails by [3, 6], to vector-valued feature images. Instead of gray or color values, the whole analysis works on local orientations, extracted from omnidirectional input images and represented as low-frequency vector-valued view(More)
In software development, it is important to assure a high level of process and software quality. In the agile context, suitable approaches to measure and analyze these aspects are hard to find. CMMI and SPICE are too heavyweighted, while EN ISO 9001 is too lightweight. To fill this gap, andrena objects ag developed ISIS, a navigation system for process and(More)
Optical Rails is a purely view-based method for steering a robot through a network of positions in a known environment. Navigation is based on images aquired by an upward-looking omnidirectional camera; even a very modest quality of the optical system is sufficient, since all views are represented in terms of low-order basis functions (spherical harmonics).(More)