Fakultät für Mathematik und Physik
https://www.repo.uni-hannover.de/handle/123456789/7
Frei zugängliche Publikationen aus der Fakultät für Mathematik und Physik2024-03-19T01:14:06ZLimSt – Ein Fragebogen zur Erhebung von Lernstrategien im mathematikhaltigen Studium
https://www.repo.uni-hannover.de/handle/123456789/16771
LimSt – Ein Fragebogen zur Erhebung von Lernstrategien im mathematikhaltigen Studium
Liebendörfer, Michael; Göller, Robin; Biehler, Rolf; Hochmuth, Reinhard; Kortemeyer, Jörg; Ostsieker, Laura; Rode, Jana; Schaper, Niclas
Learning strategies are important in students’ learning. Several studies in tertiary mathematics education focused on learning strategies. Yet, there is no instrument that adequately covers the specialties of learning university mathematics. We present a newly developed questionnaire to fill this gap. It has been developed and validated in eight quantitative and two qualitative studies. On both scale and item level, specialties of university mathematics are taken into account. The instrument is still general in the sense that it allows to measure students’ use of learning strategies across mathematics courses of different study programs like mathematics major programs, engineering and economics, as well as teacher education.
2020-01-01T00:00:00ZErratum: The construction problem for Hodge numbers modulo an integer in positive characteristic (Forum Math. Sigma 8 (2020) E45 DOI: 10.1017/fms.2020.48)
https://www.repo.uni-hannover.de/handle/123456789/16773
Erratum: The construction problem for Hodge numbers modulo an integer in positive characteristic (Forum Math. Sigma 8 (2020) E45 DOI: 10.1017/fms.2020.48)
van Dobben de Bruyn, Remy; Paulsen, Matthias
The original publication of this article includes an error introduced during the publication process. On three occasions, Remark 4.4 has been incorrectly referred to as Theorem 4.4. Please find listed below the corrected paragraphs containing the errors in the original publication along with the page number of where they occur.
2021-01-01T00:00:00ZIntercomparison of Monte Carlo calculated dose enhancement ratios for gold nanoparticles irradiated by X-rays: Assessing the uncertainty and correct methodology for extended beams
https://www.repo.uni-hannover.de/handle/123456789/16769
Intercomparison of Monte Carlo calculated dose enhancement ratios for gold nanoparticles irradiated by X-rays: Assessing the uncertainty and correct methodology for extended beams
Rabus, H.; Li, W.B.; Villagrasa, C.; Schuemann, J.; Hepperle, P.A.; de la Fuente Rosales, L.; Beuve, M.; Di Maria, S.; Klapproth, A.P.; Li, C.Y.; Poignant, F.; Rudek, B.; Nettelbeck, H.
Results of a Monte Carlo code intercomparison exercise for simulations of the dose enhancement from a gold nanoparticle (GNP) irradiated by X-rays have been recently reported. To highlight potential differences between codes, the dose enhancement ratios (DERs) were shown for the narrow-beam geometry used in the simulations, which leads to values significantly higher than unity over distances in the order of several tens of micrometers from the GNP surface. As it has come to our attention that the figures in our paper have given rise to misinterpretation as showing ‘the’ DERs of GNPs under diagnostic X-ray irradiation, this article presents estimates of the DERs that would have been obtained with realistic radiation field extensions and presence of secondary particle equilibrium (SPE). These DER values are much smaller than those for a narrow-beam irradiation shown in our paper, and significant dose enhancement is only found within a few hundred nanometers around the GNP. The approach used to obtain these estimates required the development of a methodology to identify and, where possible, correct results from simulations whose implementation deviated from the initial exercise definition. Based on this methodology, literature on Monte Carlo simulated DERs has been critically assessed.
2021-01-01T00:00:00ZRelaxed parameter conditions for chemotactic collapse in logistic-type parabolic–elliptic Keller–Segel systems
https://www.repo.uni-hannover.de/handle/123456789/16760
Relaxed parameter conditions for chemotactic collapse in logistic-type parabolic–elliptic Keller–Segel systems
Black, Tobias; Fuest, Mario; Lankeit, Johannes
We study the finite-time blow-up in two variants of the parabolic–elliptic Keller–Segel system with nonlinear diffusion and logistic source. In n-dimensional balls, we consider {ut=∇·((u+1)m-1∇u-u∇v)+λu-μu1+κ,0=Δv-1|Ω|∫Ωu+uand {ut=∇·((u+1)m-1∇u-u∇v)+λu-μu1+κ,0=Δv-v+u,where λ and μ are given spatially radial nonnegative functions and m, κ> 0 are given parameters subject to further conditions. In a unified treatment, we establish a bridge between previously employed methods on blow-up detection and relatively new results on pointwise upper estimates of solutions in both of the systems above and then, making use of this newly found connection, provide extended parameter ranges for m, κ leading to the existence of finite-time blow-up solutions in space dimensions three and above. In particular, for constant λ, μ> 0 , we find that there are initial data which lead to blow-up in (JL) if 0≤κ<min{12,n-2n-(m-1)+}ifm∈[2n,2n-2n)or0≤κ<min{12,n-1n-m2}ifm∈(0,2n),and in (PE) if m∈[1,2n-2n) and 0≤κ<min{(m-1)n+12(n-1),n-2-(m-1)nn(n-1)}.
2021-01-01T00:00:00Z