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The focusing and coherence properties of the NanoMAX Kirkpatrick–Baez mirror system at the fourth-generation MAX IV synchrotron in Lund have been characterized. The direct measurement of nano-focused X-ray beams is possible by scanning of an X-ray waveguide, serving basically as an ultra-thin slit. In quasi-coherent operation, beam sizes of down to 56 nm (FWHM, horizontal direction) can be achieve
Production studies show that anaphoric reference is bimodal. Speakers can introduce a referent in speech by also using a localizing gesture, assigning a specific locus in space to it. Referring back to that referent, speakers then often accompany a spoken anaphor with a localizing anaphoric gesture (i.e., indicating the same locus). Speakers thus create visual anaphoricity in parallel to the anaph
A key assumption conventionally made by flexible head-mounted eye-tracking systems is often invalid: The eye center does not remain stationary w.r.t. the eye camera due to slippage. For instance, eye-tracker slippage might happen due to head acceleration or explicit adjustments by the user. As a result, gaze estimation accuracy can be significantly reduced. In this work, we propose Grip, a novel g
On-line teaching situations where a tutor and their students are remote from each other mean that contact between them is reduced compared with teaching in a classroom. We report an initial study of two-way gaze sharing between a tutor and a group of students, who were in different locations. A 45-min class consisted of an introductory lecture followed by an exercise in using two software tools, o
BACKGROUND: People with intellectual disability (ID) have high prevalence of psychiatric disorders, but even higher rates of prescription of psychotropic drugs. METHODS: Using Swedish national registers, we identified a group of older people with ID and diagnosis of mood disorders (ICD-10 codes F32-F39) and/or anxiety (ICD-10 code F4) during 2006-2012 (n = 587) and a referent group of people from
Consider the coupling of two multi-physics systems of time-dependent ODEs. We propose a new Waveform iteration type method for coupling which uses asynchronous communication to be both parallel in time and fast in convergence. Analytical results show convergence in the continuous setting and numerical results for two coupled head equations show good performance of this method, which is both parall
Our aim is to construct efficient preconditioners for high order discontinuous Galerkin (DG) methods. We consider the DG spectral element method with Gauss‐Lobatto‐Legendre nodes (DGSEM‐GL) for the 1D linear advection equation. It has been shown in [4] that DGSEM‐GL has the summation‐by‐parts (SBP) property and an equivalent finite volume (FV) discretization is presented in [3]. Thus we present a
We suggest a new multigrid preconditioning strategy for use in Jacobian-free Newton–Krylov (JFNK) methods for the solution of algebraic equation systems arising from implicit Discontinuous Galerkin (DG) discretisations. To define the new preconditioner, use is made of an auxiliary first-order finite volume discretisation that refines the original DG mesh, but can still be implemented algebraically
Conformational entropies are of great interest when studying the binding of small ligands to proteins or the interaction of proteins. Unfortunately, there are no experimental methods available to measure conformational entropies of all groups in a protein. Instead, they are normally estimated from molecular dynamics (MD) simulations, although such methods show problems with convergence and correla
The magnitude of variation in the gaze position signals recorded by an eye tracker, also known as its precision, is an important aspect of an eye tracker’s data quality. However, data quality of eye-tracking signals is still poorly understood. In this paper, we therefore investigate the following: (1) How do the various available measures characterizing eye-tracking data during fixation relate to
We present a software package, Modes, offering h-adaptive and p-adaptive linear multistep methods for first order initial value problems in ordinary differential equations. The implementation is based on a new parametric, grid-independent representation of multistep methods [Arévalo and Söderlind 2017]. Parameters are supplied for over 60 methods. For nonstiff problems, all maximal order methods (
We apply spectral stability theory to investigate nonlinear gravity waves in the atmosphere. These waves are determined by modulation equations that result from Wentzel-Kramers-Brillouin theory. First, we establish that plane waves, which represent exact solutions to the inviscid Boussinesq equations, are spectrally stable with respect to their nonlinear modulation equations under the same conditi
In a k-step adaptive linear multistep methods the coefficients depend on the k − 1 most recent step size ratios. In a similar way, both the actual and the estimated local error will depend on these step ratios. The classical error model has been the asymptotic model, chp+ 1y(p+ 1)(t), based on the constant step size analysis, where all past step sizes simultaneously go to zero. This does not refle
We consider thermal fluid structure interaction with a partitioned approach, where typically, a finite volume and a finite element code would be coupled. As a model problem, we consider two coupled Poisson problems with heat conductivities $$\lambda _1$$, $$\lambda _2$$ in one dimension on intervals of length $$l:1$$ and $$l:2$$. Hereby, we consider linear discretizations on arbitrary meshes, such
We present novel coupling schemes for partitioned multiphysics simulation that combine four important aspects for strongly coupled problems: implicit coupling per time step, fast and robust acceleration of the corresponding iterative coupling, support for multirate time stepping, and higher-order convergence in time. To achieve this, we combine waveform relaxation—a known method to achieve higher-
We consider initial value problems (IVPs) where we are interested in a quantity of interest(QoI) that is the integral in time of a functional of the solution. For these, we analyze goal orientedtime adaptive methods that use only local error estimates. A local error estimate and timestepcontroller for step-wise contributions to the QoI are derived. We prove convergence of the error in theQoI for
Computed tomography (CT)-derived finite element (FE) models have been proposed as a tool to improve the current clinical assessment of osteoporosis and personalized hip fracture risk by providing an accurate estimate of femoral strength. However, this solution has two main drawbacks, namely: (i) 3D CT images are needed, whereas 2D dual-energy x-ray absorptiometry (DXA) images are more generally av
The emergence of new high brilliance and high coherence facilities such as X-ray Free Electron Lasers (XFELs) and 4th generation synchrotrons open a new era in X-ray optics. Dynamical diffraction effects before disregarded are starting to play a role in the beam control of large scale facilities. In the case of XFEL facilities the temporal characteristics of the dynamical diffraction by thin perfe
