Search results for "mathematics"
showing 10 items of 22031 documents
‘What’s the Moment Thingy?’– On the Emergence of Subject-Specific Knowledge in CLIL Classroom Interaction
2017
Situated in the European CLIL context where mainstream schools may opt for teaching content subjects through the medium of a foreign or second language, this paper explores secondary school physics classrooms, taught through English in Finland. The focus is on the role of classroom interaction in the emergence of subject-specific knowledge during six consecutive lessons, with particular attention to how one key concept in physics, ‘moment’, is handled. This micro-longitudinal approach shows that while the students are struggling between the everyday and the academic meanings of the word ‘moment’ throughout, there are also clear signs of progression. These signs show, for example, in student…
Lobster and cod benefit from small-scale northern marine protected areas: inference from an empirical before - after control-impact study
2013
Published version of an article from the journal: Proceedings of the Royal Society B-Biological Sciences. Alsop available from the Royal Society: http://dx.doi.org/10.1098/rspb.2012.2679 Open Access Marine protected areas (MPAs) are increasingly implemented as tools to conserve and manage fisheries and target species. Because there are opportunity costs to conservation, there is a need for science-based assessment of MPAs. Here, we present one of the northernmost documentations of MPA effects to date, demonstrated by a replicated before-after control-impact (BACI) approach. In 2006, MPAs were implemented along the Norwegian Skagerrak coast offering complete protection to shellfish and parti…
Theoretical conditions for the coexistence of viral strains with differences in phenotypic traits : A bifurcation analysis
2019
We investigate the dynamics of a wild-type viral strain which generates mutant strains differing in phenotypic properties for infectivity, virulence and mutation rates. We study, by means of a mathematical model and bifurcation analysis, conditions under which the wild-type and mutant viruses, which compete for the same host cells, can coexist. The coexistence conditions are formulated in terms of the basic reproductive numbers of the strains, a maximum value of the mutation rate and the virulence of the pathogens. The analysis reveals that parameter space can be divided into five regions, each with distinct dynamics, that are organized around degenerate Bogdanov–Takens and zero-Hopf bifurc…
Efficient Linear-Scaling Density Functional Theory for Molecular Systems
2013
Despite recent progress in linear scaling (LS) density function theory (DFT), the computational cost of the existing LS methods remains too high for a widespread adoption at present. In this work, we exploit nonorthogonal localized molecular orbitals to develop a series of LS methods for molecular systems with a low computational overhead. High efficiency of the proposed methods is achieved with a new robust two-stage variational procedure or by replacing the optimization altogether with an accurate nonself-consistent approach. We demonstrate that, even for challenging condensed-phase systems, the implemented LS methods are capable of extending the range of accurate DFT simulations to molec…
A posteriori error majorants of the modeling errors for elliptic homogenization problems
2013
In this paper, we derive new two-sided a posteriori estimates of the modeling errors for linear elliptic boundary value problems with periodic coefficients solved by homogenization. Our approach is based on the concept of functional a posteriori error estimation. The estimates are obtained for the energy norm and use solely the global flux of the non-oscillatory solution of the homogenized model and solution of a boundary value problem on the cell of periodicity.
A posteriori modelling-discretization error estimate for elliptic problems with L ∞-Coefficients
2017
We consider elliptic problems with complicated, discontinuous diffusion tensor A0. One of the standard approaches to numerically treat such problems is to simplify the coefficient by some approximation, say Aϵ, and to use standard finite elements. In [19] a combined modelling-discretization strategy has been proposed which estimates the discretization and modelling errors by a posteriori estimates of functional type. This strategy allows to balance these two errors in a problem adapted way. However, the estimate of the modelling error was derived under the assumption that the difference A0 - Aϵ becomes small with respect to the L∞-norm. This implies in particular that interfaces/discontinui…
A comparison of performance of Deca Iron and Triple Deca Iron ultra-triathletes
2014
This study intended to compare the performance of ultra-triathletes competing in a Deca Iron ultra-triathlon (i.e. 10 times 3.8 km swimming, 180 km cycling, and 42.2 km running) with the performance of athletes competing in a Triple Deca Iron ultra-triathlon (i.e. 30 times 3.8 km swimming, 180 km cycling, and 42.2 km running). Split and overall race times of six male finishers in a Deca Iron ultra-triathlon and eight male finishers in a Triple Deca Iron ultra-triathlon were analysed using multiple t-tests, linear and non-linear regression analyses, and analysis of variance. Among the 19 starters (i.e. 17 men and two women) in the Deca Iron ultra-triathlon, six men (i.e. 35.3% of all starter…
Modeling mass transfer in fracture flows with the time domain-random walk method
2019
The time domain-random walk method was developed further for simulating mass transfer in fracture flows together with matrix diffusion in surrounding porous media. Specifically, a time domain-random walk scheme was developed for numerically approximating solutions of the advection-diffusion equation when the diffusion coefficient exhibits significant spatial variation or even discontinuities. The proposed scheme relies on second-order accurate, central-difference approximations of the advective and diffusive fluxes. The scheme was verified by comparing simulated results against analytical solutions in flow configurations involving a rectangular channel connected on one side with a porous ma…
Research in mathematics education as a component in the initial training of early childhood teachers
2013
En este trabajo presentamos una experiencia didáctica llevada a cabo en la asignatura Didáctica de la Matemática en Educación Infantil impartida en 4º curso del Grado de Maestro en Educación Infantil de la Universidad de Valencia. A través de esta experiencia hemos pretendido acercar la investigación en el campo de la didáctica de la matemática a los futuros maestros de infantil. Con el fin de poder evaluar el impacto que dicha experiencia ha tenido, hemos procedido a administrar un pre-test y un post-test que indagan en el conocimiento que los estudiantes poseen sobre las investigaciones en educación matemática infantil y la utilidad que le otorgan. Hemos analizado los datos obtenidos y en…
Evidence for the production of three massive vector bosons with the ATLAS detector
2019
A search for the production of three massive vector bosons in proton–proton collisions is performed using data at TeV recorded with the ATLAS detector at the Large Hadron Collider in the years 2015–2017, corresponding to an integrated luminosity of 79.8 fb−1. Events with two same-sign leptons ℓ (electrons or muons) and at least two reconstructed jets are selected to search for . Events with three leptons without any same-flavour opposite-sign lepton pairs are used to search for , while events with three leptons and at least one same-flavour opposite-sign lepton pair and one or more reconstructed jets are used to search for . Finally, events with four leptons are analysed to search for and .…