Technical University of Dortmund

About: Technical University of Dortmund is a education organization based out in Dortmund, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Context (language use) & Large Hadron Collider. The organization has 13028 authors who have published 27666 publications receiving 615557 citations. The organization is also known as: Dortmund University & University of Dortmund.

Adaptation to visuomotor rotations in younger and older adults.

Abstract: Adaptation to a visuomotor rotation is known to be impaired at older adult age. The authors examined whether the impairment is present already at preretirement age and whether it depends on the difficulty of the adaptation task. Moreover, the authors tested predictions of the hypothesis that the age-related impairment pertains primarily to strategic corrections and the explicit knowledge on which they are based but not to the acquisition of an (implicit) internal model of the novel visuomotor transformation. The authors found an age-related impairment of adaptation and explicit knowledge already at preretirement age but no age-related change of aftereffects. With an incremental simplification of the adaptation task, age-related changes were able to be eliminated. Individual differences of the quality of explicit knowledge were associated with differences of adaptation, but not of aftereffects. When age groups were matched by explicit knowledge, age-related impairments of adaptation largely disappeared. However, a reliable difference remained in one of the experiments, suggesting that other processes of adjustment to a visuomotor rotation might be affected by aging as well.

Measurement of the inclusive e ± p scattering cross section at high inelasticity y and of the structure function F L

Abstract: A measurement is presented of the inclusive neutral current e\pm p scattering cross section using data collected by the H1 experiment at HERA during the years 2003 to 2007 with proton beam energies Ep of 920, 575, and 460 GeV. The kinematic range of the measurement covers low absolute four-momentum transfers squared, 1.5 GeV2 < Q2 < 120 GeV2, small values of Bjorken x, 2.9 \cdot 10-5 < x < 0.01, and extends to high inelasticity up to y = 0.85. The structure function FL is measured by combining the new results with previously published H1 data at Ep = 920 GeV and Ep = 820 GeV. The new measurements are used to test several phenomenological and QCD models applicable in this low Q2 and low x kinematic domain.

Faster k-Medoids Clustering: Improving the PAM, CLARA, and CLARANS Algorithms.

Abstract: Clustering non-Euclidean data is difficult, and one of the most used algorithms besides hierarchical clustering is the popular algorithm Partitioning Around Medoids (PAM), also simply referred to as k-medoids.

Design of an UWB indoor-positioning system for UAV navigation in GNSS-denied environments

Abstract: Commonly used unmanned aerial vehicle (UAV) platforms rely on the use of global navigation satellite system (GNSS) receivers for navigation. To enable the autonomous navigation of cooperative UAVs in GNSS-denied environments, the use of an ultra-wideband (UWB) positioning system is proposed. This paper discusses the design and evaluation of a practical and cooperative UWB positioning system using newly available integrated radio frequency hardware and antennas. Constellation-aware parameters, as well as other effects like antenna characteristics, are taken into consideration. A non-line-of-sight rejection is implemented based on the ratio of the first path compared to the power of the cumulated channel impulse response. An experiment covering a range of positions and orientations is conducted to gain a broad, representative set of results to assess the system accuracy in real-life usage. In a first experiment the system performance achieves a root-mean-square error of under 10 cm in the horizontal plane and under 20 cm in the three-dimensional space with a probability of 95 %. A GNSS emulation system is implemented to evaluate the real-time in-flight use of the UWB positioning system on an experimental UAV carrier. A proof of concept is given that the GNSS emulation may be used with commercially available UAV platforms to augment those systems with indoor navigation capabilities.