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- Lewandowski, D. (author) doctoral thesis 2008
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Chi, N.T. (author)When a pile is driven into soil, the soil is pushed away which results in significant changes in both stress state and strain state. Using Finite Element Code to simulate the pile installation process has been not yet completely successful partly due to the limited knowledge of the governing behavior of the soil around a displacement pile. An...master thesis 2008
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Amiri-Simkooei, A.R. (author)A methodology is developed to analyze a multivariate linear model, which occurs in many geodetic and geophysical applications. Proper analysis of multivariate GPS coordinate time-series is considered to be an application. General, special, and more practical stochastic models are adopted to assess the noise characteristics of multivariate time...journal article 2008
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Karimi Nejadasl, F. (author), Gorte, B.G.H. (author), Snellen, M.M. (author), Hoogendoorn, S.P. (author)In this paper, we address the registration of two images as an optimization problem within indicated bounds. Our contribution is to identify such situations where the optimum value represents the real transformation parameters between the two images. Consider for example Mean Square Error (MSE) as the energy function: Ideally, a minimum in MSE...conference paper 2008
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Andersson, R. (author), Bouwman, W.G. (author), Luding, S. (author), De Schepper, I.M. (author)Extracting structure and ordering information from the bulk of granular materials is a challenging task. Here we present Spin-Echo Small Angle Neutron Scattering Measurements in combination with computer simulations on a fine powder of silica, before and after uniaxial compression. The cohesive powder packing is modeled by using molecular...journal article 2008
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- Ooms, T. (author), Koek, W. (author), Westerweel, J. (author) journal article 2008
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Bos, M.S. (author), Fernandes, R.M.S. (author), Williams, S.D.P. (author), Bastos, L. (author)It has been generally accepted that the noise in continuous GPS observations can be well described by a power-law plus white noise model. Using maximum likelihood estimation (MLE) the numerical values of the noise model can be estimated. Current methods require calculating the data covariance matrix and inverting it, which is a significant...journal article 2007
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Slysz, W. (author), Wegrzecki, M. (author), Bar, J. (author), Grabiec, P. (author), Gorska, M. (author), Reiger, E. (author), Dorenbos, S. (author), Zwiller, V. (author), Milostnaya, I. (author), Minaeva, O. (author)We have fabricated fiber-coupled superconducting single-photon detectors (SSPDs), designed for quantum-correlationtype experiments. The SSPDs are nanostructured (~100-nm wide and 4-nm thick) NbN superconducting meandering stripes, operated in the 2 to 4.2 K temperature range, and known for ultrafast and efficient detection of visible to...conference paper 2007
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Slob, E.C. (author), Wapenaar, C.P.A. (author)It is shown that the electromagnetic Green's functions of any linear medium with arbitrary heterogeneity can be obtained from the cross?correlation, or the cross?convolution, of two recordings at different receiver locations in an open system. Existing representations are known for cross?correlations where time?reversal invariance is exploited...journal article 2007
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Draganov, D.S. (author), Wapenaar, K. (author), Mulder, W. (author), Singer, J. (author), Verdel, A. (author)The retrieval of the earth's reflection response from cross?correlations of seismic noise recordings can provide valuable information, which may otherwise not be available due to limited spatial distribution of seismic sources. We cross?correlated ten hours of seismic background?noise data acquired in a desert area. The cross?correlation results...journal article 2007
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Besteman, K. (author)Screening of charged particles by mobile ions in electrolytes is a major focus of such diverse fields as polymer physics, nanofluidics, colloid science, and biophysics. Yet the physics often remains poorly understood. Here we focus on two counterintuitive phenomena induced by multivalent counterions: charge inversion and DNA condensation.doctoral thesis 2006
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Hinnen, K. (author), Verhaegen, M. (author), Doelman, N. (author)Most adaptive optics systems (AO) are based on a simple control law that is unable to account for the temporal evolution of the wavefront. In this paper, a recently proposed data-driven H2-optimal control approach is demonstrated on an AO laboratory setup. The proposed control approach does not assume any form of decoupling and can therefore...conference paper 2006
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Hinnen, K. (author), Doelman, N. (author), Verhaegen, M. (author)The problem of finding the closed-loop optimal controller is formulated in an H2-optimal control framework. This provides a natural way to account for the fact that in many AO systems the wavefront phase cannot be measured directly. Given a multi-variable disturbance model of both wavefront slopes and wavefront phases,3 this provides a general...conference paper 2005
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Hinnen, K. (author), Verhaegen, M. (author), Doelman, N. (author)Even though the wavefront distortion introduced by atmospheric turbulence is a dynamic process, its temporal evolution is usually neglected in the adaptive optics (AO) control design. Most AO control systems consider only the spatial correlation in a separate wavefront reconstruction step. By accounting for the temporal evolution of the...conference paper 2005
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- Kruglov, T.V. (author) doctoral thesis 2005
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- Somers, P.A.A.M. (author), Bhattacharya, N. (author) journal article 2005
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Vitkalov, S.A. (author), Zheng, H. (author), Sarachik, M.P. (author), Klapwijk, T.M. (author)Measurements in magnetic fields applied at small angles relative to the electron plane in silicon MOSFETs indicate a factor of two increase of the frequency of Shubnikov-de Haas oscillations at H>H_{sat}. This signals the onset of full spin polarization above H_{sat}, the parallel field above which the resistivity saturates to a constant value.journal article 2000
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Dyskin, A.V. (author)The fracture process in heterogeneous materials (e.g., concrete, rock, aggregate composites) under uniaxial compression proceeds in three stages differing in the scale levels involved. Stage 1 is the accumulation of wing cracks formed under compression from pre-existing defects. The wing cracks themselves cannot grow to an extent sufficient to...journal article 1998
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- Van Drunen, M.A. (author) doctoral thesis 1996
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Helwig, A.W.S. (author)In the Eurofix system, DGPS corrections are transmitted using an already existing infrastructure: the Loran-C system. Primarily, this provides a cost-effective way to supply coverage for DGPS-corrections over a large area. Secondly, the use of the Loran-C navigation system in combination with normal GPS will yield a combined system with improved...master thesis 1995