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Simons, E.C. (author), Weerheijm, J. (author), Sluys, Lambertus J. (author)Alumina ceramic is often used in armour systems. This material is known to have a brittle response under tensile loading, while a ductile response is found when sufficiently high pressures are reached. During projectile impact a ceramic material experiences both tensile loading and high pressures, hence fails in both a brittle and ductile way....journal article 2019
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Merino Martinez, R. (author), Sijtsma, P. (author), Rubio Carpio, A. (author), Zamponi, R. (author), Luesutthiviboon, S. (author), Malgoezar, A.M.N. (author), Snellen, M. (author), Schram, Christophe (author), Simons, D.G. (author)Most acoustic imaging methods assume the presence of point sound sources and, hence, may fail to correctly estimate the sound emissions of distributed sound sources, such as trailing-edge noise. In this contribution, three integration techniques are suggested to overcome this issue based on models considering a single point source, a line...journal article 2019
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Vieira, A.E. (author), Mehmood, Umair (author), Merino Martinez, R. (author), Snellen, M. (author), Simons, D.G. (author)The capacity of airports is limited due to the negative community response to noise. Traditional metrics, such as the A-weighted maximum sound pressure level (Lp;A;max), indicate the overall noise generated by an aircraft flyover but do not provide any information on tonal components or frequency variations in time that are known to affect...conference paper 2019
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VanDercreek, Colin (author), Sijtsma, P. (author), Snellen, M. (author), Ragni, D. (author), Avallone, F. (author), Simons, D.G. (author)A mathematical model is proposed that evaluates acoustic propagation of turbulent boundary layer waves on top of a cavity enclosing a microphone. The goal is to optimize these cavity geometries to improve the signal-to-noise ratio of acoustic measurements. This model predicts the attenuation of the turbulent boundary layer fluctuations...conference paper 2019
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Hunink, Johannes (author), Simons, Gijs (author), Suárez-Almiñana, Sara (author), Solera, Abel (author), Andreu, Joaquín (author), Giuliani, Matteo (author), Zamberletti, Patrizia (author), Grillakis, Manolis (author), Bastiaanssen, W.G.M. (author)European agriculture and water policies require accurate information on climate change impacts on available water resources. Water accounting, that is a standardized documentation of data on water resources, is a useful tool to provide this information. Pan-European data on climate impacts do not recognize local anthropogenic interventions in...journal article 2019
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Merino Martinez, R. (author), Pieren, R.D. (author), Snellen, M. (author), Simons, D.G. (author)Noise emissions from wind turbines are one of the main issues that the wind energy industry must deal with nowadays. Strict noise regulations often prevent wind turbines to operate at maximum power conditions, causing large losses of power production and, hence, of revenue. Several noise reduction measures have been proposed so far, but the...conference paper 2019
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Mohammadloo, Tannaz H. (author), Snellen, M. (author), Renoud, Weston (author), Beaudoin, Jonathan (author), Simons, D.G. (author)In this contribution a method for correcting bathymetric measurements affected by inaccurate water column sound speed profiles (SSPs) is presented. The method exploits the redundancy in the multibeam echosounder measurements obtained from the overlap of adjacent swaths by minimizing the difference between depths along overlapping swaths. Two...journal article 2019
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Gaida, T.C. (author), Ali, Tengku Afrizal Tengku (author), Snellen, M. (author), Amiri Simkooei, A. (author), van Dijk, T.A.G.P. (author), Simons, D.G. (author)Multi-frequency backscatter data collected from multibeam echosounders (MBESs) is increasingly becoming available. The ability to collect data at multiple frequencies at the same time is expected to allow for better discrimination between seabed sediments. We propose an extension of the Bayesian method for seabed classification to multi...journal article 2018
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Simons, E.C. (author), Weerheijm, J. (author), Sluys, Lambertus J. (author)Plasticity models are frequently used to describe ceramic materials. Well established and often used ceramic models are those by Johnson and Holmquist. These are softening plasticity models for which mesh dependency is a well known problem. A viscosity or rate dependency can be added to the material model to provide regularization and solve...journal article 2018
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Snellen, M. (author), Gaida, T.C. (author), Koop, L. (author), Alevizos, Evangelos (author), Simons, D.G. (author)Obtaining an overview of the spatial and temporal distribution of seabed sediments is of high interest for multiple research disciplines. Multibeam echosounders allow for the mapping of seabed sediments with high area coverage. In this paper, the repeatability of acoustic classification derived from multibeam echosounder backscatter is addressed...journal article 2018
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Marin, L. (author), Masschelein, Jan (author), Simons, Maarten (author)In the age of web 2.0, the university is constantly challenged to re-adapt its ‘old-fashioned’ pedagogies to the new possibilities opened up by digital technologies. This article proposes a rethinking of the relation between university and (digital) technologies by focusing not on how technologies function in the university, but on their...journal article 2018
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Luesutthiviboon, S. (author), Malgoezar, A.M.N. (author), Snellen, M. (author), Sijtsma, P. (author), Simons, D.G. (author)Beamforming performance can be improved in two ways: optimizing the location of microphones on the acoustic array and applying advanced beamforming algorithms. In this study, the effects of the two approaches are studied. An optimization method is developed to optimize the location of microphones for an acoustic array used in an open-jet...conference paper 2018
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Mohammadloo, Tannaz H. (author), Snellen, M. (author), Simons, D.G. (author), Dierikx, Ben (author), Bicknese, Simon (author)Reliable information about the seafloor and river-bed bathymetry is of high interest for a large number of applications. A Multi-Beam echo sounder (MBES) system is able to produce high-resolution bathymetry data at relatively small cost. These measurements, providing a depth for each beam and every ping, are processed to obtain a more ordered...journal article 2018
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Vieira, A.E. (author), Malgoezar, A.M.N. (author), Snellen, M. (author), Simons, D.G. (author)The shielding of engine noise by the airframe of an aircraft is considered an effective way of reducing noise levels on the ground. Noise shielding in conventional aircraft is mainly due to the presence of the wings and most model predictions of full-scale aircraft neglect the effect of the airfoil curvature. The engine is typically simpliffied...conference paper 2018
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Sahai, A.K. (author), Snellen, M. (author), Simons, D.G. (author)This paper presents an approach with which perceived audible differences in aircraft sounds can be quantified and presented in an objective manner. The objective quantification of the subjectively heard audible differences is intended to serve two primary goals. It can firstly enable developers of auralization technology to make the auralized...journal article 2018
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Simons, Gerard (author), Herholz, Sebastian (author), Petitjean, V.J.P. (author), Rapp, Tobias (author), Ament, Marco (author), Lensch, Hendrick (author), Dachsbacher, Carsten (author), Eisemann, M. (author), Eisemann, E. (author)Physically based rendering is a well-understood technique to produce realistic-looking images. However, different algorithms exist for efficiency reasons, which work well in certain cases but fail or produce rendering artefacts in others. Few tools allow a user to gain insight into the algorithmic processes. In this work, we present such a tool,...journal article 2018
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Mohammadloo, Tannaz H. (author), Snellen, M. (author), Simons, D.G. (author)In this contribution bathymetric uncertainties induced by the use of frequency modulated (FM) signals for multi-beam-echo-sounder (MBES) measurements are quantified and their relevance for MBES bathymetric uncertainty predictions is assessed. When switching to FM, the quality of depth measurements can get deteriorated due to the Doppler...journal article 2018
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Simons, L.P.A. (author), van den Heuvel, Wouter A.C. (author), Jonker, C.M. (author)Within groups that are starting a healthy lifestyle intervention together, there is potential for social e-support, as an addition to individual coaching. However, the support technology should be low-tech, low-threshold and preferably already omnipresent. A WhatsApp group was chosen as support tool, given the large variety of groups normally...book chapter 2018
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Gaida, T.C. (author), Snellen, M. (author), van Dijk, Thaiënne A.G.P. (author), Simons, D.G. (author)Extensive seabed sediment mapping is highly relevant to describe marine ecosystems and to quantify the distribution and extent of benthic habitats. Compared to traditional mapping methods, primarily based on bed sampling, multibeam echo sounding (MBES) is a time-efficient tool to acquire high-resolution bathymetric and backscatter data over...journal article 2018
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Merino Martinez, R. (author), Heblij, Sander (author), Bergmans, Dick H.T. (author), Snellen, M. (author), Simons, D.G. (author)Accurate predictions of aircraft noise levels are desirable to enforce noise control regulations around airports and to evaluate noise abatement procedures. The current best practice noise contour prediction models assume certain default net thrust values depending on the engine type and aircraft altitude. This Paper proposes a method for...journal article 2018