Search results for " menetelmä"
showing 10 items of 273 documents
Discrete element model for viscoelastic materials with brittle fracture : applications on glacier dynamics
2017
The stress-strain state and stabilization of viscoelastoplastic, imperfect moving web continuum
2014
On modelling and stability of axially moving viscoelastic materials
2013
A Bayesian spatio‐temporal analysis of markets during the Finnish 1860s famine
2022
We develop a Bayesian spatio-temporal model to study pre-industrial grain market integration during the Finnish famine of the 1860s. Our model takes into account several problematic features often present when analysing multiple spatially interdependent time series. For example, compared with the error correction methodology commonly applied in econometrics, our approach allows simultaneous modelling of multiple interdependent time series avoiding cumbersome statistical testing needed to predetermine the market leader as a point of reference. Furthermore, introducing a flexible spatio-temporal structure enables analysing detailed regional and temporal dynamics of the market mechanisms. Appl…
Scattering and point spectra for elliptic systems in domains with cylindrical ends
2004
Viktor Kalvinen tieteellisen laskennan alaan kuuluva väitöskirjatutkimus käsittelee elliptisiä reuna-arvotehtäviä sylinteripäisissä alueissa. Sylinteripäinen alue mallitetaan työssä eräänlaisena aaltoputkena, johon tulee ja josta lähtee erilaisia aaltoja. Näiden aaltojen amplitudi voi kasvaa eksponentiaalisesti kohti ääretöntä. Kalvine on kehittänyt tutkimuksessaan ns. augmentoidun sirontamatriisin, joka perinteisiin sirontamatriiseihin verrattuna kykenee käsittelemään myös amplitudiltaan eksponentiaalisesti muuttuvia aaltoja. Työssä esitellään myös numeerinen menetelmä kyseisen sirontamatriisin laskemiseksi. In the thesis we consider dissipative elliptic boundary value problems in domains …
Shape sensitivity analysis for numerical solution of free boundary problems
2005
Kari Kärkkäinen tutki tehokkaita ja käyttökelpoisia ratkaisumenetelmiä vapaita pintoja sisältäville malleille. Hän tarkastelee väitöksessään numeerisessa simuloinnissa käytettävien vapaan pinnan ratkaisumenetelmien tehokkuutta ja niiden parantamista käyttäen matemaattista lähestymistapaa. Kärkkäinen ehdottaa ratkaisumenetelmää, jonka avulla vapaan pinnan tehtävien ratkaiseminen on helpompaa. Menetelmää voi myös soveltaa erilaisiin tilanteisiin. This work is devoted to the development of efficient and robust solution algorithms for a class of free boundary problems. This consists of mathematical analysis of different model problems and the description of numerical implementation to generic f…
Letting Art Teach Aesthetics, Math and Language
2020
This papers presents a practical work model as well as an educational theory discussion on the status and potential of art work in teaching and learning math in early childhood education. The central idea is to let the child’s free creative art activity reveal, or “teach”, whatever mathematical thinking was inherent in the creative process. Paying careful attention to art and math adequate language in “meta talks” with children about their art work, is found to be a rich tool in enhancing the young learner’s development of aesthetic, numeric and linguistic literacies in gainful interplay. A field study in preschool teacher education is reviewed, including a mapping of Alan Bishop’s [2] math…
Single-particle and collective excitations in the transitional nucleus 166Os
2021
The mean lifetimes of the lowest energy 2+, 8+ and 9− states in 166Os have been measured using the recoil distance Doppler-shift method in conjunction with a selective recoil-decay tagging technique. These measurements extend studies into the most neutron-deficient mass region accessible to current experimental methods. The B(E2; 2+ → 0+) = 7(2) W.u. extracted from these measurements is markedly lower than those observed in the heavier even-mass Os isotopes. The 8+ and 9− states yield reduced transition probabilities that are consistent with single-particle transitions. While these values may indicate a departure from collective structure, the level scheme and the underlying nuclear configu…
Directly measured and self-reported physical activity in a sample of Finnish secondary school students
2012
Previous studies based on self-reports show that a majority of children and adolescents in Western countries fail to achieve the recommendation of 60 minutes moderate to vigorous physical activity (PA) on a daily basis. The specific aim of the study was to analyze the relationship between directly measured and self-reported PA in a cross-sectional sample of Finnish secondary school students. Moreover, how large proportion of adolescents accumulate at least 60 minutes of moderate to vigorous PA on a daily basis using self-reports and direct measure scores. Methods: Participants were recruited from a secondary school located in Northeast Finland. The sample comprised 96 students (58 girls, 38…