Now showing items 11-20 of 4704
LEDs on HVPE grown GaN substrates: influence of macroscopic surface features
We demonstrate the strong influence of GaN substrate surface morphology on optical properties and performance of light emitting devices grown on freestanding GaN. As-grown freestanding HVPE GaN substrates show excellent ...
Is the medial prefrontal cortex necessary for Theory of Mind?
Background: Successful social interaction relies on the ability to attribute mental states to other people. Previous functional neuroimaging studies have shown that this process, described as Theory of Mind (ToM) or ...
Testing the temperature limits of GaN-based HEMT devices
The high temperature stability of AlGaN/GaN and lattice-matched InAlN/GaN heterostructure FETs has been evaluated by a stepped temperature test routine under large-signal operation. While AlGaN/GaN high-electron mobility ...
Does tinnitus distress depend on age of onset?
Objectives: Tinnitus is the perception of a sound in the absence of any physical source of it. About 5 - 15% of the population report hearing such a tinnitus and about 1 - 2% suffer from their tinnitus leading to anxiety, ...
Uncertainty analysis for the classification of multispectral satellite images using SVMs and SOMs
Classification of multispectral remotely sensed data with textural features is investigated with a special focus on uncertainty analysis in the produced land-cover maps. Much effort has already been directed into the ...
The mirrored triangles illusion: on the perceived distance between triangles in mirror image arrangement
(Universität Ulm, 2017-10-18)
The mirrored triangles illusion is described and investigated. Two black isosceles triangles are arranged symmetrically with respect to a vertical plane such that the apices face each other. While keeping their distance ...
Assessment of a millimeter-wave antenna system for MIMO radar applications
(Universität Ulm, 2016-11-22)
Multiple-input-multiple-output (MIMO) radars show improved angular resolution compared to traditional phased-array radar systems. Exploiting the advantages of MIMO radars could thus significantly improve the performances ...
The challenges of measuring Integrated antennas at millimeter-wave frequencies
(Universität Ulm, 2017)
The increasing demand for radar sensors and the wide distribution of handheld communication devices push the development of low-cost components with a small form factor. One approach to achieve smaller, low-cost devices ...
Enhancements in mm-wave antenna measurements: automatic alignment and achievable accuracy
(Universität Ulm, 2017-10)
Due to various error sources, accurate integrated antenna measurements can be difficult to achieve. This study analyses the accuracy of a measurement set-up for radiation pattern (RP), directivity and gain measurements. ...
Stepped-carrier OFDM-radar processing scheme to retrieve high resolution range-velocity profile at low sampling rate
(Universität Ulm, 2017-09-29)
Recent publications show that the potential of using orthogonal frequency division multiplexing waveforms is radar signals. Since the range resolution is proportional to the RF bandwidth, the major obstacle that obstructs ...