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Bookholt, F.D. (author), Monsuur, H.N. (author), Gibbs, S. (author), Vermolen, F.J. (author)In this work, we develop a mathematical formalism based on a 3D in vitro model that is used to simulate the early stages of angiogenesis. The model treats cells as individual entities that are migrating as a result of chemotaxis and durotaxis. The phenotypes used here are endothelial cells that can be distinguished into stalk and tip (leading)...journal article 2016
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Astudillo, R. (author), Van Gijzen, M.B. (author)Discretization of (linearized) convection-diffusion-reaction problems yields a large and sparse non symmetric linear system of equations, Ax = b. (1) In this work, we compare the computational behavior of the Induced Dimension Reduction method (IDR(s)) [10], with other short-recurrences Krylov methods, specifically the Bi-Conjugate Gradient...report 2016
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Van Velzen, C. (author), Altaf, M.U. (author), Verlaan, M. (author)Data assimilation methods provide a means to handle the modeling errors and uncertainties in sophisticated ocean models. In this study, we have created an OpenDA-NEMO framework unlocking the data assimilation tools available in OpenDA for use with NEMO models. This includes data assimilation methods, automatic parallelization, and a recently...journal article 2016
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Cong, F. (author), Oosterlee, C.W. (author)This paper enhances a well-known dynamic portfolio management algorithm, the BGSS algorithm, proposed by Brandt et al. (Review of Financial Studies, 18(3):831–873, 2005). We equip this algorithm with the components from a recently developed method, the Stochastic Grid Bundling Method (SGBM), for calculating conditional expectations. When solving...journal article 2016
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Van Wijngaarden-van Rossum, W.K. (author), Van Paassen, L.A. (author), Vermolen, F.J. (author), Van Meurs, G.A.M. (author), Vuik, C. (author)Biogrout is a method to strengthen granular soil, which is based on microbial-induced carbonate precipitation. To model the Biogrout process, a reactive transport model is used. Since high flow rates are undesirable for the Biogrout process, the model equations can be solved with a standard Galerkin finite element method. The Biogrout process...journal article 2016
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Carinci, G. (author), Giardina, C. (author), Redig, F.H.J. (author), Sasamoto, T. (author)By using the algebraic construction outlined in Carinci et al. (arXiv:?1407.?3367, 2014), we introduce several Markov processes related to the Uq(su(1,1)) quantum Lie algebra. These processes serve as asymmetric transport models and their algebraic structure easily allows to deduce duality properties of the systems. The results include: (a) the...journal article 2016
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Van Ginkel, B. (author), Redig, F.H.J. (author), Sau, F. (author)We study the “Immediate Exchange Model”, a wealth distribution model introduced in Heinsalu and Patriarca (Eur Phys J B 87:170, 2014). We prove that the model has a discrete dual, where the duality functions are natural polynomials associated to the Gamma distribution with shape parameter 2 and are exactly those connecting the Brownian Energy...journal article 2016
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Mouchet, A. (author), Cornaton, F. (author), Deleersnijder, E.L.C. (author), Delhez, E.J.M. (author)The concept of age is widely used to quantify the transport rate of tracers - or pollutants - in the environment. The age focuses only on the time taken to reach a given location and disregards other aspects of the path followed by the tracer parcel. To keep track of the subregions visited by the tracer parcel along this path, partial ages are...journal article 2016
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Zhang, H. (author), Rutherford, E.S. (author), Mason, D.M. (author), Breck, J.T. (author), Wittmann, M.E. (author), Cooke, R.M. (author), Lodge, D.M. (author), Rothlisberger, J.D. (author), Zhu, Z. (author), Johnson, T.B. (author)Nonindigenous bigheaded carps (Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix; hereafter, “Asian carps” [AC]) threaten to invade and disrupt food webs and fisheries in the Laurentian Great Lakes through their high consumption of plankton. To quantify the potential effects of AC on the food web in Lake Erie, we developed an...journal article 2016
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Dekking, F.M. (author)Morphisms are homomorphisms under the concatenation operation of the set of words over a finite alphabet. Changing the elements of the finite alphabet does not change the morphism in an essential way. We propose a method to select a unique representative from all these morphisms. This has applications to the classification of the shift dynamical...journal article 2016
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Combet, V. (author), Genoud, S.F. (author)We establish the classification of minimal mass blow-up solutions of the L2 critical inhomogeneous nonlinear Schrödinger equation i?tu+?u+|x|?b|u|4?2bNu=0, thereby extending the celebrated result of Merle (Duke Math J 69(2):427–454, 1993) from the classic case b=0 to the case 0<b<min{2,N}, in any dimension N?1.journal article 2016
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De Laat, D. (author)In this thesis we develop techniques for solving problems in extremal geometry. We give an infinite dimensional generalization of moment techniques from polynomial optimization. We use this to construct semidefinite programming hierarchies for approximating optimal packing densities and ground state energies of particle systems. For this we...doctoral thesis 2016
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Setekera, R. (author)With the current increasing demand for faster and more reliable communication and computing electronic devices such as faster wireless communication networks, circuit designers are forced to carry out device optimization in order to achieve the maximum possible performance. To enable full circuit optimization, designers depend on compact models...doctoral thesis 2016
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Van Wijngaarden-van Rossum, W.K. (author)Biogrout is a method to reinforce sand and gravel by the production of calcium carbonate. This calcium carbonate is produced using micro-organisms that are either present in the subsoil or injected into it. The micro-organisms are supplied with urea and calcium. Subsequently, they catalyse the hydrolysis of urea, by which carbonate is formed. In...doctoral thesis 2016
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Vuik, M.J. (author), Ryan, J.K. (author)In Vuik and Ryan [J. Comput. Phys., 270 (2014), pp. 138--160] we studied the use of troubled-cell indicators for discontinuity detection in nonlinear hyperbolic partial differential equations and introduced a new multiwavelet technique to detect troubled cells. We found that these methods perform well as long as a suitable, problem-dependent...journal article 2016
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Van Zwieten, J.S.B. (author), Sanderse, B. (author), Hendrix, M.H.V. (author), Vuik, C. (author), Henkes, R.A.W.M. (author)One-dimensional models for multiphase flow in pipelines are commonly discretised using first-order Finite Volume (FV) schemes, often combined with implicit time-integration methods. While robust, these methods introduce much numerical diffusion depending on the number of grid points. In this paper we propose a high-order, space-time...report 2015
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- Sonneveld, P. (author) report 2015
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Qiu, Y. (author), Van Gijzen, M.B. (author), Van Wingerden, J.W. (author), Verhaegen, M.H.G. (author), Vuik, C. (author)In this manuscript, we study preconditioning techniques for optimal in-domain control of the Navier-Stokes equation, where the control only acts on a few parts of the domain. Optimization and linearization of the optimal in-domain control problem results in a generalized linear saddle-point system. The Schur complement for the generalized saddle...report 2015
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Van Iersel, L.J.J. (author)Hoe kunnen we reconstrueren hoe hedendaagse organismen zijn ontstaan uit verre voorouders door verschillende evolutionaire processen? Dit is het doel van onderzoek op het gebied van fylogenetische netwerken: grafen die evolutionaire verwantschappen beschrijven. Leo van Iersel ontving in 2011 een Veni-beurs van NWO voor onderzoek op dit gebied....journal article 2015
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Qiu, Y. (author), van Gijzen, M.B. (author), van Wingerden, J.W. (author), Verhaegen, M. (author), Vuik, C. (author)Multilevel sequentially semiseparable (MSSS) matrices form a class of structured matrices that have low-rank off-diagonal structure, which allows the matrix-matrix operations to be performed in linear computational complexity. MSSS preconditioners are computed by replacing the Schur complements in the block LU factorization of the global linear...report 2015