17 research outputs found
Demo. Detection Tracking and Recognition of Human Poses for Real Time applications
Until now, most of the computer games are played with a controller. But there is a big difference between pushing a button to jump and jumping yourself. Currently we are developing new tools which allow players to get rid off controllers and play games using intuitive body movements and poses. In this demo, we illustrate real-time pose tracking and recognition applied to pose-driven spatial game
Correspondence estimation in image pairs
This article provides an overview of current techniques for dense geometric correspondence estimation. We will first formally define geometric correspondence and investigate the different types of image pairs. Then we briefly look at the classic approaches to correspondence estimation, at their feasibility and flaws for simultaneous dense estimation. We will focus on the Bayesian approach, which is suited very well for this task and for which several promising algorithms have recently been developed. After having a look at the future of the Bayesian approaches, we conclude with a discussion
4f→5d and anomalous emission in Yb<sup>2+</sup> doped NaI, SrI<sub>2</sub> and LaI<sub>3</sub> powders prepared by rapid melting and quenching in vacuum
The temperature dependent luminescence properties of Yb2+ doped in NaI, SrI2 and LaI3 powders, prepared by a fast synthesis method involving the rapid melting and quenching in vacuum are reported. The 4f→5d excitation and emission spectra obtained for SrI2:Yb2+ were found to be in accordance with earlier work validating the synthesis methods. In both NaI and SrI2, doping with Yb2+ leads to 5d→4f emission, whereas in LaI3 no 5d→4f emission was found but instead anomalous emission is observed. In order to understand the observed differences, vacuum referred binding energy (VRBE) schemes were constructed for NaI and LaI3. For this purpose a NaI:Tm3+ sample was prepared, establishing the Tm3+ charge transfer energy at 3,5 eV. The VRBE energy scheme of NaI clearly reveals that the 5d states of Yb2+ and the other divalent lanthanides are well below the conduction band making 5d→4f emission possible. In LaI3 the 5d states are almost 1 eV inside the conduction band, which explains the absence of 5d→4f emission and the presence of the anomalous emission.Applied SciencesRST/Luminescence Material
Large scale non-linear finite element analyses of reinforced concrete structures
Due to practical and economic reasons the design of complex concrete structures is often based on linear FEA with rather large elements. The inelastic behavior of reinforced concrete can lead to significant load redistributions which can only be predicted using non-linear FEA (NLFEA). This work aims at developing a method for performing large scale NLFEA of concrete structures, both with respect to material behavior and assessment of the structural safety. The present paper compares results from a simple beam experiment with NLFEA on two different element size scales. The NLFEA on both scales predict consistent ULS capacity. A localized crack pattern was only observed at medium scale, but the corresponding SLS crack widths were non-conservative due to a nonlocalized equilibrium path. A scale transition procedure should preserve the localized crack pattern.Structural EngineeringCivil Engineering and Geoscience
The skin of Van Gogh's paintings
Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Modeling of long-term deformations and damage accumulation in masonry
Civil Engineering and Geoscience
Graph-time spectral analysis for atrial fibrillation
Atrial fibrillation is a clinical arrhythmia with multifactorial mechanisms still unresolved. Time-frequency analysis of epicardial electrograms has been investigated to study atrial fibrillation. However, deeper understanding can be achieved by incorporating the spatial dimension. Unfortunately, the physical models describing the spatial relations of atrial fibrillation signals are complex and non-linear; hence, conventional signal processing techniques to study electrograms in the joint space, time, and frequency domain are less suitable. In this study, we wish to put forward a radically different approach to analyze atrial fibrillation with a higher-level model. This approach relies on graph signal processing to represent the spatial relations between epicardial electrograms. To capture the frequency content along both the time and graph domain, we propose the joint graph and short-time Fourier transform. The latter allows us to analyze the spatial variability of the electrogram temporal frequencies. With this technique, we found the spatial variation of the atrial electrograms decreases during atrial fibrillation since the high temporal frequencies of the atrial waves reduce. The proposed analysis further confirms that the ventricular activity is smoother over the atrial area compared with the atrial activity. Besides using the proposed graph-time analysis to conduct a first study on atrial fibrillation, we demonstrate its potential by applying it to the cancellation of ventricular activity from the atrial electrograms. Experimental results on simulated and real data further corroborate our findings in this atrial fibrillation study.Circuits and SystemsMultimedia ComputingBiomechanical Engineerin
Database guided detection of anatomical landmark points in 3D images of the heart
Information and Communication Theory GroupElectrical Engineering, Mathematics and Computer Scienc
Towards an integrated simulation of casting and structural performance of flowable fibre-reinforced concrete
Most recent studies on fibre-reinforced self-compacting concrete agree on the impact of the casting conditions on the fibre orientation and distribution, and its consequence thereof on the structural performance. A substantial number of investigations are continuously contributing to gain experience on the use of flowable FRC for different structural applications, and will ultimately serve to define the principles to incorporate the effects of fibre orientation and distribution on design recommendations.The present paper describes a recent modelling approach that can take into account the configuration of the fibres in a structural element, i.e. their orientation and distribution, to predict the structural performance. The modelling approach has previously been presented and validated for structural elements in which the actual fibre configuration was characterized using Computer Tomography scanning. In this paper, the modelling approach is applied to analyse a wall element whose fibre configuration was obtained using the simulation of the concrete flow during casting.The integrated simulation of casting and structural performance provides an actual framework to incorporate the effect of the fibre configuration in the prediction of structural behaviour. This should contribute to more reliable and effective use of fibre-reinforced self-compacting concrete.Applied Mechanic
Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator
A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU project.Electrical Sustainable EnergyElectrical Engineering, Mathematics and Computer Scienc