Adaptive Energy Preserving Methods for Partial Differential Equations

A method for constructing first integral preserving numerical schemes for time-dependent partial differential equations on non-uniform grids is presented. The method can be used with both finite difference and partition of unity approaches, thereby also including finite element approaches. The schemes are then extended to accommodate $r$-, $h$- and $p$-adaptivity. The method is applied to the Korteweg-de Vries equation and the Sine-Gordon equation and results from numerical experiments are presented.Comment: 27 pages; some changes to notation and figure

Variational image regularization with Euler's elastica using a discrete gradient scheme

This paper concerns an optimization algorithm for unconstrained non-convex problems where the objective function has sparse connections between the unknowns. The algorithm is based on applying a dissipation preserving numerical integrator, the Itoh--Abe discrete gradient scheme, to the gradient flow of an objective function, guaranteeing energy decrease regardless of step size. We introduce the algorithm, prove a convergence rate estimate for non-convex problems with Lipschitz continuous gradients, and show an improved convergence rate if the objective function has sparse connections between unknowns. The algorithm is presented in serial and parallel versions. Numerical tests show its use in Euler's elastica regularized imaging problems and its convergence rate and compare the execution time of the method to that of the iPiano algorithm and the gradient descent and Heavy-ball algorithms

Dissipative numerical schemes on Riemannian manifolds with applications to gradient flows

This paper concerns an extension of discrete gradient methods to finite-dimensional Riemannian manifolds termed discrete Riemannian gradients, and their application to dissipative ordinary differential equations. This includes Riemannian gradient flow systems which occur naturally in optimization problems. The Itoh--Abe discrete gradient is formulated and applied to gradient systems, yielding a derivative-free optimization algorithm. The algorithm is tested on two eigenvalue problems and two problems from manifold valued imaging: InSAR denoising and DTI denoising.Comment: Post-revision version. To appear in SIAM Journal on Scientific Computin

Complete analytic anharmonic hyper-Raman scattering spectra

We present the first computational treatment of the complete second-order vibrational perturbation theory applied to hyper-Raman scattering spectroscopy. The required molecular properties are calculated in a fully analytic manner using a recently developed program [Ringholm, Jonsson and Ruud, J. Comp. Chem., 2014, 35, 622] that utilizes recursive routines. For some of the properties, these calculations are the first analytic calculations of their kind at their respective levels of theory. We apply this approach to the calculation of the hyper-Raman spectra of methane, ethane and ethylene and compare these to available experimental data. We show that the anharmonic corrections have a larger effect on the vibrational frequencies than on the spectral intensities, but that the inclusion of combination and overtone bands in the anharmonic treatment can improve the agreement with the experimental data, although the quality of available experimental data limits a detailed comparison

Innovative forms of citizen participation at the fringe of the formal planning system

In the Nordic countries, we are witnessing a proliferation of novel and more experimental ways of citizen and authority interaction within the field of urban planning and governance. These formats are seen in urban regeneration projects and planning experiments that endorse more inclusive interactions between public authorities and local actors than in the traditional formal hearings. The intention of this article is to explore the potential of these forms of participation in contributing to social innovation particularly related to including citizens that are difficult to reach, and in creating new arenas for interaction and collaboration. Theoretically, the article is inspired by the concepts of social innovation, planning as experimentation (Hillier, 2007; Nyseth, Pløger, & Holm, 2010), and co-creation (Voorberg, Bekkers, & Tummers, 2013). Empirically, the article draws on three different cases from Norway and Denmark which entailed some novel ways of involving local citizens in urban planning. Finally, the article discusses how formal planning procedures can gain inspiration from such initiatives

When Innovative Ideas Encounter Institutions: An Analytical Model

This paper presents an analytical model for studying “encounters” that take place when ideas for innovation meet institutions (The IIE-model). Our model aims to expand the dichotomous barriers/driver approach in innovation research. Building on the theoretical contributions of studies on institutional logics and change, this model presents a dynamic, institution-based understanding of what happens when innovative ideas meet institutions. Four ideal types of encounters describe the mutual impact of institutions and innovative ideas. This paper aims to contribute to a wider and more nuanced understanding of the dynamics of innovation processes

Improved Pregnancy Outcome in Type 1 Diabetic Women With Microalbuminuria or Diabetic Nephropathy: Effect of intensified antihypertensive therapy?

OBJECTIVE—To describe pregnancy outcome in type 1 diabetic women with normoalbuminuria, microalbuminuria, or diabetic nephropathy after implementation of an intensified antihypertensive therapeutic strategy

Participation according to the law? The research-based knowledge on citizen participation in Norwegian municipal planning

Source at http://doi.org/10.30689/EJSD2018:67.1650-9544. Citizen participation is enshrined in the Norwegian Planning and Building Act (PBA) 1985 and accentuated by the 2008 revision of the PBA. In this article, we ask if the research on participation in municipal planning is sufficient to draw conclusions on whether the Act is effective with regard to both the spirit and the letter of the law. The guiding framework for the analysis is based on the concepts of input and output legitimacy and the distinction between ‘tidy’ and ‘untidy’ participation. The analysis is based on scientific publications published after the 2008 revision of the PBA. We find that the majority of the research concentrates on zoning plans and municipalityinitiated ‘tidy’ participation. As a result, there are gaps in the research with regard to both the planning context and the interconnectedness of different forms of participation. Therefore, the research reviewed can only partially inform the law-makers on the functioning of the Act