A spatial light modulator using BSO crystals

The combined use of the photoelectric and electro-optic properties of the Bi12SiO20 (BSO)-crystal leads to a new possibility of realizing a spatial light modulator. Under certain geometrical conditions, which will be discussed, it is possible to realize, that the BSO-crystal becomes birefringent depending on the local illuminance; the physical connection between the distributions of birefringence and illuminance will be shown. The BSO-crystal combined with a polarizer setup works as a spatial light modulator or as an incoherent to coherent converter

New light valve based in photoinduced space charge fields in BSO-crystals

The combined photoelectric and electrooptic properties of the BSO-crystal lead to a new possibility of realizing a real time spatial light modulator. Under certain geometrical conditions the crystal becomes birefringent in dependence on the local illuminance. Together with a suitable polarizer setup the crystal works as well as an incoherent to coherent converter as for contrast inversion

Grundlagenuntersuchung, Entwicklung und Erprobung optischer Sensoren für die Qualitätssicherung und zum Einsatz an Montagerobotern in der flexiblen Montage : Teilprojekt A4

Die dreidimensionale berührungslose Objektvermessung ist eine zentrale Sensoraufgabe in der industriellen Montage und Qualitätssicherung. Hierfür geeignet sind optische Triangulationsverfahren, die sich im Vergleich zu anderen Verfahren durch hohe relative Distanz- und Lateralauflösung sowie geringen apparativen Aufwand auszeichnen

Testing mean differences among groups : multivariate and repeated measures analysis with minimal assumptions

To date, there is a lack of satisfactory inferential techniques for the analysis of multivariate data in factorial designs, when only minimal assumptions on the data can be made. Presently available methods are limited to very particular study designs or assume either multivariate normality or equal covariance matrices across groups, or they do not allow for an assessment of the interaction effects across within-subjects and between-subjects variables. We propose and methodologically validate a parametric bootstrap approach that does not suffer from any of the above limitations, and thus provides a rather general and comprehensive methodological route to inference for multivariate and repeated measures data. As an example application, we consider data from two different Alzheimers disease (AD) examination modalities that may be used for precise and early diagnosis, namely, single-photon emission computed tomography (SPECT) and electroencephalogram (EEG). These data violate the assumptions of classical multivariate methods, and indeed classical methods would not have yielded the same conclusions with regards to some of the factors involved.(VLID)250099

Neural correlates of verbal working memory: an fMRI meta-analysis

Verbal Working memory (vWM) capacity measures the ability to maintain and manipulate verbal information for a short period of time. The specific neural correlates of this construct are still a matter of debate. The aim of this study was to conduct a coordinate-based meta-analysis of 42 fMRI studies on visual vWM in healthy subjects (n=795, males=459, females=325, unknown=11; age range: 18-75). The studies were obtained after an exhaustive literature search on PubMed, Scopus, Web of Science, and Brainmap database. We analyzed regional activation differences during fMRI tasks with the anisotropic effect-size version of seed-based d mapping software (ES-SDM). The results were further validated by performing jackknife sensitivity analyses and heterogeneity analyses. We investigated the effect of numerous relevant influencing factors by fitting corresponding linear regression models. We isolated consistent activation in a network containing fronto-parietal areas, right cerebellum, and basal ganglia structures. Regarding lateralization, the results pointed towards a bilateral frontal activation, a left-lateralization of parietal regions and a right-lateralization of the cerebellum, indicating that the left-hemisphere concept of vWM should be reconsidered. We also isolated activation in regions important for response inhibition, emphasizing the role of attentional control in vWM. Moreover, we found a significant influence of mean reaction time, load and age on activation associated with vWM. Activation in left medial frontal gyrus, left precentral gyrus and left precentral gyrus turned out to be positively associated with mean reaction time whereas load was associated with activation across the PFC, fusiform gyrus, parietal cortex and parts of the cerebellum. In the latter case activation was mainly detectable in both hemispheres whereas the influence of age became manifest predominantly in the left hemisphere. This led us to conclude that future vWM studies should take these factors into consideration

Von 27 Bauteilen auf 1 Bauteil reduziert

Dank Kombination von Kompetenzen aus Getriebeentwicklung, Konstruktion, additiver Fertigung und spanender Fertigung konnte ein Planetenträger entwickelt werden, der deutlich leichter und steifer ist als das Referenzbauteil

Benchmark of 6D SLAM (6D simultaneous localisation and mapping) algorithms with robotic mobile mapping systems

This work concerns the study of 6DSLAM algorithms with an application of robotic mobile mapping systems. The architecture of the 6DSLAM algorithm is designed for evaluation of different data registration strategies. The algorithm is composed of the iterative registration component, thus ICP (Iterative Closest Point), ICP (point to projection), ICP with semantic discrimination of points, LS3D (Least Square Surface Matching), NDT (Normal Distribution Transform) can be chosen. Loop closing is based on LUM and LS3D. The main research goal was to investigate the semantic discrimination of measured points that improve the accuracy of final map especially in demanding scenarios such as multi-level maps (e.g., climbing stairs). The parallel programming based nearest neighborhood search implementation such as point to point, point to projection, semantic discrimination of points is used. The 6DSLAM framework is based on modified 3DTK and PCL open source libraries and parallel programming techniques using NVIDiA CUDA. The paper shows experiments that are demonstrating advantages of proposed approach in relation to practical applications. The major added value of presented research is the qualitative and quantitative evaluation based on realistic scenarios including ground truth data obtained by geodetic survey. The research novelty looking from mobile robotics is the evaluation of LS3D algorithm well known in geodesy