Institution
University of Stuttgart
Education•Stuttgart, Germany•
About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.
Papers published on a yearly basis
Papers
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TL;DR: Three-dimensional arrays of optical Yagi-Uda nano-antennas with high directivity are fabricated and the incoming light is received efficiently at the resonant wavelength in the near-infrared.
Abstract: Future photonic circuits with the capability of high-speed data processing at optical frequencies will rely on the implementation of efficient emitters and detectors on the nanoscale. Towards this goal, bridging the size mismatch between optical radiation and subwavelength emitters or detectors by optical nanoantennas is a subject of current research in the field of plasmonics. Here we introduce an array of three-dimensional optical Yagi-Uda antennas, fabricated using top-down fabrication techniques combined with layer-by-layer processing. We show that the concepts of radiofrequency antenna arrays can be applied to the optical regime proving superior directional properties compared with a single planar optical antenna, particularly for emission and reception into the third dimension. Measuring the optical properties of the structure reveals that impinging light on the array is efficiently absorbed on the subwavelength scale because of the high directivity. Moreover, we show in simulations that combining the array with suitable feeding circuits gives rise to the prospect of beam steering at optical wavelengths.
311 citations
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TL;DR: It is argued that MIF exhibits enzymatic oxidoreductase activity, that this activity is dependent on the presence of the catalytic center that is formed by cysteine residues 57 and 60, and that certain MIF-mediated immune processes are due to the Cysteine-mediated redox mechanism.
311 citations
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05 May 2012TL;DR: An interactive installation is designed that uses visual feedback to the incidental movements of passers-by to communicate its interactivity and reveals mirrored user silhouettes and images are more effective than avatar-like representations.
Abstract: In this paper we present our findings from a lab and a field study investigating how passers-by notice the interactivity of public displays. We designed an interactive installation that uses visual feedback to the incidental movements of passers-by to communicate its interactivity. The lab study reveals: (1) Mirrored user silhouettes and images are more effective than avatar-like representations. (2) It takes time to notice the interactivity (approx. 1.2s). In the field study, three displays were installed during three weeks in shop windows, and data about 502 interaction sessions were collected. Our observations show: (1) Significantly more passers-by interact when immediately showing the mirrored user image (+90%) or silhouette (+47%) compared to a traditional attract sequence with call-to-action. (2) Passers-by often notice interactivity late and have to walk back to interact (the landing effect). (3) If somebody is already interacting, others begin interaction behind the ones already interacting, forming multiple rows (the honeypot effect). Our findings can be used to design public display applications and shop windows that more effectively communicate interactivity to passers-by.
310 citations
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TL;DR: It is shown that phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ) — a key player in the structure and function of the Golgi complex — is a physiological substrate of PKD.
Abstract: Protein kinase D (PKD) regulates the fission of vesicles originating from the trans-Golgi network1,2. We show that phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ) — a key player in the structure and function of the Golgi complex3 — is a physiological substrate of PKD. Of the three PKD isoforms, only PKD1 and PKD2 phosphorylated PI4KIIIβ at a motif that is highly conserved from yeast to humans. PKD-mediated phosphorylation stimulated lipid kinase activity of PI4KIIIβ and enhanced vesicular stomatitis virus G-protein transport to the plasma membrane. The identification of PI4KIIIβ as one of the PKD substrates should help to reveal the molecular events that enable transport-carrier formation.
309 citations
01 Apr 2016
TL;DR: In this article, a Monte Carlo approach is proposed to improve the accuracy of SfM-based DEMs and minimise the associated field effort by robust determination of suitable lower-density deployments of ground control.
Abstract: Structure-from-motion (SfM) algorithms greatly facilitate the production of detailed topographic models from photographs collected using unmanned aerial vehicles (UAVs). However, the survey quality achieved in published geomorphological studies is highly variable, and sufficient processing details are never provided to understand fully the causes of variability. To address this, we show how survey quality and consistency can be improved through a deeper consideration of the underlying photogrammetric methods. We demonstrate the sensitivity of digital elevation models (DEMs) to processing settings that have not been discussed in the geomorphological literature, yet are a critical part of survey georeferencing, and are responsible for balancing the contributions of tie and control points. We provide a Monte Carlo approach to enable geomorphologists to (1) carefully consider sources of survey error and hence increase the accuracy of SfM-based DEMs and (2) minimise the associated field effort by robust determination of suitable lower-density deployments of ground control. By identifying appropriate processing settings and highlighting photogrammetric issues such as over-parameterisation during camera self-calibration, processing artefacts are reduced and the spatial variability of error minimised.
We demonstrate such DEM improvements with a commonly-used SfM-based software (PhotoScan), which we augment with semi-automated and automated identification of ground control points (GCPs) in images, and apply to two contrasting case studies — an erosion gully survey (Taroudant, Morocco) and an active landslide survey (Super-Sauze, France). In the gully survey, refined processing settings eliminated step-like artefacts of up to ~ 50 mm in amplitude, and overall DEM variability with GCP selection improved from 37 to 16 mm. In the much more challenging landslide case study, our processing halved planimetric error to ~ 0.1 m, effectively doubling the frequency at which changes in landslide velocity could be detected. In both case studies, the Monte Carlo approach provided a robust demonstration that field effort could by substantially reduced by only deploying approximately half the number of GCPs, with minimal effect on the survey quality. To reduce processing artefacts and promote confidence in SfM-based geomorphological surveys, published results should include processing details which include the image residuals for both tie points and GCPs, and ensure that these are considered appropriately within the workflow.
308 citations
Authors
Showing all 28043 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yi Chen | 217 | 4342 | 293080 |
Robert J. Lefkowitz | 214 | 860 | 147995 |
Michael Kramer | 167 | 1713 | 127224 |
Andrew G. Clark | 140 | 823 | 123333 |
Stephen D. Walter | 112 | 513 | 57012 |
Fedor Jelezko | 103 | 413 | 42616 |
Ulrich Gösele | 102 | 603 | 46223 |
Dirk Helbing | 101 | 642 | 56810 |
Ioan Pop | 101 | 1370 | 47540 |
Niyazi Serdar Sariciftci | 99 | 591 | 54055 |
Matthias Komm | 99 | 832 | 43275 |
Hans-Joachim Werner | 98 | 317 | 48508 |
Richard R. Ernst | 96 | 352 | 53100 |
Xiaoming Sun | 96 | 382 | 47153 |
Feng Chen | 95 | 2138 | 53881 |