Leibniz University of Hanover

About: Leibniz University of Hanover is a education organization based out in Hanover, Niedersachsen, Germany. It is known for research contribution in the topics: Finite element method & Computer science. The organization has 14283 authors who have published 29845 publications receiving 682152 citations.

Real-time stereo vision system using semi-global matching disparity estimation: Architecture and FPGA-implementation

Abstract: This paper describes a new architecture and the corresponding implementation of a stereo vision system that covers the entire stereo vision process including noise reduction, rectification, disparity estimation, and visualization Dense disparity estimation is performed using the non-parametric rank transform and semi-global matching (SGM), which is among the top performing stereo matching methods and outperforms locally-based methods in terms of quality of disparity maps and robustness under difficult imaging conditions Stream-based processing of the SGM despite its non-scan-aligned, complex data dependencies is achieved by a scalable, systolic-array-based architecture This architecture fulfills the demands of real-world applications regarding frame rate, depth resolution and low resource usage The architecture is based on a novel two-dimensional parallelization concept for the SGM An FPGA implementation on a Xilinx Virtex-5 generates disparity maps of VGA images (640×480 pixel) with a 128 pixel disparity range under real-time conditions (30 fps) at a clock frequency as low as 39 MHz

Creativity and Openness: Further Validation of Two Creative Product Measures

Abstract: This study sought to further validate two measures of creative imagination, and studied their relation to other creativity and personality measures. 151 college students completed the Urban and Jellen (1996) Test of Creative Thinking-Drawing Production (TCT-DP), an inventory of past creative accomplishments, a Thematic Apperception Test (TAT) story, and scales for creative personality and the 5-factor model. 86 of these participants also created autophotographic essays depicting themselves, scored for individuality/richness by consensual assessments. TCT-DP protocols were scored according to the manual, and also consensually assessed by teams of artist- and psychologist-judges. Factorial validity and relations to consensual assessments supported convergent and discriminant validity of the TCT-DP. The TCT-DP also correlated significantly with other creative products-the individuality of photo essays and rated creativity of TAT stories. Photo individuality correlated with past creative accomplishments in se...

Sensitivity and performance of the Advanced LIGO detectors in the third observing run

Abstract: On April 1st, 2019, the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO), joined by the Advanced Virgo detector, began the third observing run, a year-long dedicated search for gravitational radiation. The LIGO detectors have achieved a higher duty cycle and greater sensitivity to gravitational waves than ever before, with LIGO Hanford achieving angle-averaged sensitivity to binary neutron star coalescences to a distance of 111 Mpc, and LIGO Livingston to 134 Mpc with duty factors of 74.6% and 77.0% respectively. The improvement in sensitivity and stability is a result of several upgrades to the detectors, including doubled intracavity power, the addition of an in-vacuum optical parametric oscillator for squeezed-light injection, replacement of core optics and end reaction masses, and installation of acoustic mode dampers. This paper explores the purposes behind these upgrades, and explains to the best of our knowledge the noise currently limiting the sensitivity of each detector.

Photo-induced hydrophilicity and self-cleaning: models and reality

Abstract: Self-cleaning coatings, with benefits to environment, energy and labor saving, have attracted great attention due to their potential application in many aspects of human's daily life. In this perspective article, the recent efforts to understand and improve photo-induced hydrophilicity and self-cleaning properties of TiO2 are reviewed. Particular attention is paid to the fundamental aspects and mechanism of the photo-induced hydrophilicity effect. The challenges that need to be addressed over the coming years to improve the efficiency and extend the application are also presented.

Intra- and perioperative complications of the LeFort I osteotomy: a prospective evaluation of 1000 patients.

Abstract: The LeFort I osteotomy has become a routine procedure in elective orthognathic surgery. The authors report the occurrence of intra- or perioperative complications in a series of 1000 consecutive LeFort I osteotomies performed within a 20-year period. In total, 64 (6.4%) patients experienced complications. Anatomical complications affected 26 (2.6%), patients, including 16 (1.6%) with a deviation of the nasal septum and 10 (1.0%) with non-union of the osteotomy gap. Extensive bleeding that required blood transfusion occurred in 11 (1.1%) patients exclusively after bimaxillary corrections; in 1 patient a ligation of the external carotid artery became necessary. Significant infections such as abscesses or maxillary sinusitis occurred in 11 (1.1%) patients. No patient experienced an osteomyelitis. Ischemic complications affected 10 (1.0%) patients, including 2 (0.2%) who experienced an aseptic necrosis of the alveolar process and 8 (0.8%) who, under critical revision, were affected by retractions of the gingiva. Five (0.5%) patients experienced an insufficient fixation of the osteosynthesis material. The risk and the extent of complications was enhanced in patients with anatomical irregularities (eg, in patients with craniofacial dysplasias, orofacial clefts, or vascular anomalies). The risk of ischemic complications was enhanced in extensive dislocations or transversal segmentation of the maxilla. The authors conclude that patients with major anatomical irregularities should be informed about an enhanced risk of Le-Fort I osteotomies. Preoperative planning avoiding transversal segmentation or extensive dislocations of the maxilla should reduce the occurrence of complications. For healthy individuals, the risk of complications with the LeFort I osteotomy is considered low.