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Henze, L.A.R. (author), Mulder, I.J. (author), Stappers, P.J. (author)The increased complexity in Product Service Systems development goes hand in hand with complex heterogeneous networks. A Human-Centred Design approach has been taken to understand such networked collaboration and to develop a framework having user-experiences guiding communication and collaboration among parties. The current work elaborates on...conference paper 2013
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Shigapov, R. (author), Kashtan, B. (author), Droujinine, A. (author), Mulder, W.A. (author)We consider the problem of Q estimation from microseismic and from perforation shot data. Assuming that the source wavelet is not well known, we focused on the spectral ratio method and on source-independent viscoelastic full waveform inversion. We derived 3-D near-field approximations of monopole and dipole Green's tensors in a homogeneous...conference paper 2013
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Mulder, W.A. (author)Mass-lumped continuous finite elements allow for explicit time stepping with the second-order wave equation if the resulting integration weights are positive and provide sufficient accuracy. To meet these requirements on triangular and tetrahedral meshes, the construction of continuous finite elements for a given polynomial degree on the edges...journal article 2013
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De Eyto, A. (author), McMahon, M. (author), Mulder, K.F. (author), Wever, R. (author), De Werk, G. (author), Overschie, M.G.F. (author)Education for sustainable development fundamentally calls for a change in the way we educate (teaching methodologies), what we teach (the curriculum and subject matter), and why we do it (learning outcomes & professional impact) (Bhamra & Dewberry, 2007). But what should this change look like in Engineering and Design? This paper outlines and...conference paper 2013
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Mulder, W.A. (author), Zhebel, E. (author), Minisini, S. (author)We analyse the time-stepping stability for the 3-D acoustic wave equation, discretized on tetrahedral meshes. Two types of methods are considered: mass-lumped continuous finite elements and the symmetric interior-penalty discontinuous Galerkin method. Combining the spatial discretization with the leap-frog time-stepping scheme, which is second...journal article 2013
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Mulder, W.A. (author)Migration velocity analysis with the constant-density acoustic wave equation can be accomplished by the focusing of extended migration images, obtained by introducing a subsurface shift in the imaging condition. A reflector in a wrong velocity model will show up as a curve in the extended image. In the correct model, it should collapse to a...journal article 2013
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Bharadwaj, P. (author), Mulder, W.A. (author), Drijkoningen, G.G. (author)Least-squares inversion of seismic reflection waveforms can reconstruct remarkably detailed models of the Earth’s subsurface. However, the cycle-skipping associated with the highfrequency waveforms are responsible for spurious local minima in its objective function. Therefore, it is often difficult for descent methods to converge to the true...journal article 2013
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Zhebel, E. (author), Minisini, S. (author), Kononov, A. (author), Mulder, W.A. (author)With the rapid developments in parallel compute architectures, algorithms for seismic modeling and imaging need to be reconsidered in terms of parallelization. The aim of this paper is to compare scalability of seismic modeling algorithms: finite differences, continuous mass-lumped finite elements and discontinuous Galerkin finite elements. The...journal article 2013
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Shigapov, R. (author), Kashtan, B. (author), Droujinine, A. (author), Mulder, W.A. (author)We consider the problem of anelastic full waveform inversion in a multi-layered, isotropic viscoelastic medium from microseismic and cross-hole perforation shots. Usually, the source wavelet is not well known, so we focus on Q estimation techniques that can handle this problem. We revisit the spectral ratio method (SRM) and discuss its domain of...journal article 2013
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Anikiev, D. (author), Kashtan, B. (author), Mulder, W.A. (author)Three model parameters as a function of position describe wave propagation in an isotropic elastic medium. Ideally, imaging of data for a point scatterer that consists of a perturbation in one of the elastic parameters should only provide a reconstruction of that perturbation, without cross-talk into the other parameters. This is not the case...journal article 2013
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- Caetano, J.V. (author), Verboom, J. (author), De Visser, C.C. (author), De Croon, G.C.H.E. (author), Remes, B.D.W. (author), De Wagter, C. (author), Mulder, M. (author) conference paper 2013
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Ponomarenko, A.V. (author), Kashtan, B.M. (author), Troyan, V.N. (author), Mulder, W.A. (author)Recently, we proposed an analytical approach to invert for a smoothly varying near-surface P-wave velocity profile that has a squared slowness linearly decreasing with depth. The exact solution for such a velocity profile in the acoustic approximation can be expressed in terms of Airy functions and leads to a dispersion equation. The method was...conference paper 2013
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Mostert-van der Sar, M. (author), Mulder, I.J. (author), Remijn, L. (author), Troxler, P. (author)The third industrial revolution, triggered by Internet communication and renewable energies, can be experienced in so-called FabLabs that empower users to ‘make almost anything’. Although this does not change the need for designers to have making and prototyping skills, there is no doubt the revolution impacts the design profession in terms of...conference paper 2013
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Online Aerodynamic Model Identification using a Recursive Sequential Method for Multivariate SplinesSun, L.G. (author), De Visser, C.C. (author), Chu, Q.P. (author), Mulder, J.A. (author)Avoiding high computational loads is essential to online aerodynamic model identi- fication algorithms, which are at the heart of any model-based adaptive flight control system. Multivariate simplex B-spline (MVSB) methods are excellent function approximation tools for modeling the nonlinear aerodynamics of high performance aircraft. However,...journal article 2013
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Mulder, F.A. (author), Verlinden, J.C. (author)To train competitive sailing in a virtual setting, motion of the boat as well as haptic feedback of the sail lines is essential. When discussing virtual environments (VEs) the concept of presence is often used. In this study we develop a sailing simulator motion system to research what factors contribute to the participants’ sensation of...journal article 2013
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Verlinden, J.C. (author), Mulder, F.A. (author), Vergeest, J.S. (author), De Jonge, A. (author), Krutiy, D. (author), Nagy, Z. (author), Logeman, B.J. (author), Schouten, P. (author)In the context of sailing, wind plays an important role. However, there is little knowledge on how wind influences presence – the sense of “being there” - while immersed in a virtual setting. This article explores several wind parameters and presents a wind array to explore presence in a sail simulator. The simulation offered a virtual training...journal article 2013
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Mulder, A. (author)When cities started shrinking, governments felt they had to do something. Where the main reason for shrinking was the closing down of traditional industry, economic policies were the first to be introduced: first by subsidising and reorganising existing companies, later by trying to create a more diverse employment structure. Gradually it was...conference paper 2013
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Mulder, J.W. (author), Mulder, I.J. (author), Best, S.E. (author)The current work introduces pursenality, a photoethnographic method for self-elicitation and cocreation, which elaborates upon current photography methods used in (design) ethnography. In total 91 bachelor students in the 6th semester participated in a purse diary study and used the pursenality method to gain rich insights informing their human...conference paper 2013
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Mulder, W.A. (author)Migration velocity analysis for the two-way wave equation based on focusing extended migration images at zero subsurface offset are sensitive to the presence of multiples. Even after thorough multiple suppression, remnant multiple energy can lead to conflicting events that will focus at different velocities, one for the primary and another for...conference paper 2013
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Mulder, W.A. (author)Mass-lumped continuous finite elements provide accurate solutions of the second-order acoustic or elastic wave equation in complex geological settings, in particular in the presence of topography and large impedance contrasts. Elements of higher polynomial degree have better accuracy than those of lower degree but are also more costly. Here, the...conference paper 2013