Simplicial gauge theory and quantum gauge theory simulation

We propose a general formulation of simplicial lattice gauge theory inspired by the finite element method. Numerical tests of convergence towards continuum results are performed for several SU(2) gauge fields. Additionaly, we perform simplicial Monte Carlo quantum gauge field simulations involving measurements of the action as well as differently sized Wilson loops as functions of $\beta$.Comment: 20 pages, 6 figure

Seeing is Believing: 3D-Printed Boundary Objects for the Additive Manufacturing Twin Transition

This article describes the use of 3D-printed demonstrators as boundary objects in intra-firm collaboration processes aimed at implementing additive manufacturing (AM). AM is a disruptive digital technology with large potential environmental benefits. Demonstrators are common early in the learning process to familiarize organisations with AM, and it’s important to understand both their benefits and the limitations and risks involved. The results suggest that 3D-printed demonstrators can be effective in establishing a common minimum level of knowledge across diverse professions within the same organisation. Having physical objects available makes conversations about AM more engaging and legitimizes the idea of utilising AM as realistic. However, the fabrication of demonstrators can be a lengthy and costly process, and the result may not be a good representation of the final design. Negative experiences in such initial trials may turn managers away from AM prematurely. Many of the benefits of demonstrators can be obtained by producing low-cost miniatures and/or polymer parts that will mitigate the risks.publishedVersio

Contextual factors of external inspections and mechanisms for improvement in healthcare organizations: a realist evaluation

External inspections constitute a key element of healthcare regulation. Improved quality of care is one of the important goals of inspections but the mechanisms of how inspections might contribute to quality improvement are poorly understood. Drawing on interviews with healthcare professionals and managers and health record data from inspected organizations, we used a realist evaluation approach to explore how twelve inspections of healthcare providers in x= Norway influenced quality improvement. We found that for inspections to contribute to quality improvement, there must be contextual structures present supporting accountability and engaging staff in improvement work. When such structures are present, inspections can contribute to improvement by creating awareness of gaps between desired and current practices, which leads to readiness for change and stimulates intra-organizational reasoning around quality improvement. We discuss our findings using the theory of de- and recoupling, noting how regulators can identify decoupling between intended goals, management systems, practices, and patient outcomes. We further argue that regulators can contribute to a recoupling between these levels by having the capacity to track the providers' clinical performance over time. This will hold the organization accountable for implementing improvement measures and evaluate the effects of the measures on quality of care.publishedVersio

Verdien av en robust vannforsyning - Hvordan verdsette konsekvenser av brudd i drikkevannsforsyningen?

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Samfunnsøkonomisk optimale investeringer i robust drikkevannsinfrastruktur

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Simplicial gauge theory on spacetime

We define a discrete gauge-invariant Yang-Mills-Higgs action on spacetime simplicial meshes. The formulation is a generalization of classical lattice gauge theory, and we prove consistency of the action in the sense of approximation theory. In addition, we perform numerical tests of convergence towards exact continuum results for several choices of gauge fields in pure gauge theory.Comment: 18 pages, 2 figure

The Preterm Heart in Childhood : Left Ventricular Structure, Geometry, and Function Assessed by Echocardiography in 6-Year-Old Survivors of Periviable Births

Background-Preterm birth has been associated with increased risk of cardiovascular morbidity in adult life. We evaluated whether preterm birth is associated with deviating cardiac structure and function before school start. Methods and Results-In total, 176 children aged 6 years and born extremely preterm (EXPT; gestational age of 22-26weeks) and 134 children born at term (control [CTRL]) were studied. We used echocardiography to assess left heart dimensions, geometry, and functions. Recording and off-line analyses of echocardiographic images were performed by operators blinded to group belonging. Body size, blood pressure, and heart rate were also measured. Rates of family history of cardiovascular disease and sex distribution were similar in the EXPT and CTRL groups. Heart rate and systolic blood pressure did not differ, whereas diastolic blood pressure was slightly higher in EXPT than CTRL participants. After adjusting for body surface area, left ventricular length, width, and aortic valve annulus diameter were 3% to 5% smaller in EXPT than CTRL participants. Left ventricular longitudinal shortening and systolic tissue velocity were 7% to 11% lower, and transversal shortening fraction was 6% higher in EXPT than CTRL participants. The EXPT group also exhibited lower atrial emptying velocities than the CTRL group. Sex, fetal growth restriction, or a patent ductus arteriosus in the neonatal period did not contribute to cardiac dimensions or performance. Conclusions-Six-year-old children born extremely preterm exhibit a unique cardiac phenotype characterized by smaller left ventricles with altered systolic and diastolic functions than same-aged children born at term.Peer reviewe

Manifestly gauge invariant discretizations of the Schr\"odinger equation

Grid-based discretizations of the time dependent Schr\"odinger equation coupled to an external magnetic field are converted to manifest gauge invariant discretizations. This is done using generalizations of ideas used in classical lattice gauge theory, and the process defined is applicable to a large class of discretized differential operators. In particular, popular discretizations such as pseudospectral discretizations using the fast Fourier transform can be transformed to gauge invariant schemes. Also generic gauge invariant versions of generic time integration methods are considered, enabling completely gauge invariant calculations of the time dependent Schr\"odinger equation. Numerical examples illuminating the differences between a gauge invariant discretization and conventional discretization procedures are also presented.Comment: 22 pages, 3 figure