Search results for "virhe"
showing 10 items of 91 documents
Fully reliable a posteriori error control for evolutionary problems
2015
Ohjelmiston kehittäminen puutteellisen ja virheellisen havaintoaineiston käsittelyyn
2002
Kasusfehler in Aufsätzen finnischer Gymnasiasten
1998
Kolmasluokkalaisten sanelutesti : siirtymäajat, kokonaisajat ja virheluokittelu tietokonepohjaisessa sanelutestissä
2004
Korpusavusteinen virheanalyysi tarkkuuden kehityksestä EVK:n taitotasoilla A2–B2
2020
Artikkelissa tarkastellaan kielitaidon taitotasoittaista kehittymistä potentiaalisten esiintymien analyysin (Potential Occasion Analysis, Thewissen, 2015) avulla. Kehittymistä analysoidaan tarkkuuden näkökulmasta, ja sitä mitataan kohdekielen muoto- ja käyttökonventioista poikkeavien muotojen määrällä. Tutkimus on korpuspohjaista virheanalyysia (Corpus-aided Error Analysis, Dagneaux, Dennes & Granger, 1998), ja se perustuu taitotasoilla havaittujen, yhdeksään virheluokkaan sijoittuvien virheiden määrien tilastolliseen testaukseen. Aineistona on Kansainvälinen oppijansuomen korpus(ICLFI). Analyysi osoittaa, että merkittävintä kehitys on tasojen B1 ja B2 välillä; tasojen A2 ja B1 välillä tark…
IMI Prevention of Myopia and Its Progression
2021
The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy…
On the a posteriori error analysis for linear Fokker-Planck models in convection-dominated diffusion problems
2018
This work is aimed at the derivation of reliable and efficient a posteriori error estimates for convection-dominated diffusion problems motivated by a linear Fokker-Planck problem appearing in computational neuroscience. We obtain computable error bounds of the functional type for the static and time-dependent case and for different boundary conditions (mixed and pure Neumann boundary conditions). Finally, we present a set of various numerical examples including discussions on mesh adaptivity and space-time discretisation. The numerical results confirm the reliability and efficiency of the error estimates derived.
On a posteriori error bounds for approximations of the generalized Stokes problem generated by the Uzawa algorithm
2012
In this paper, we derive computable a posteriori error bounds for approximations computed by the Uzawa algorithm for the generalized Stokes problem. We show that for each Uzawa iteration both the velocity error and the pressure error are bounded from above by a constant multiplied by the L2-norm of the divergence of the velocity. The derivation of the estimates essentially uses a posteriori estimates of the functional type for the Stokes problem. peerReviewed
Anisometropia of spherical equivalent and astigmatism among myopes: a 23-year follow-up study of prevalence and changes from childhood to adulthood.
2017
Purpose To study anisometropia of spherical equivalent and astigmatism from the onset of myopia at school age to adulthood. Methods A total of 240 myopic schoolchildren (mean age 10.9 years), with no previous spectacles, were recruited during 1983–1984 to a randomized 3-year clinical trial of bifocal treatment of myopia. Examinations with subjective cyclopedic refraction were repeated 3 years later (follow-up 1) for 238 subjects and thereafter at the mean ages of 23.2 (follow-up 2) and 33.9 years (follow-up 3) for 178 and 134 subjects. After exclusions, the 102 subjects who attended all three follow-ups were included in the analyses. Corneal refractive power and astigmatism and anterior cha…
Node co-activations as a means of error detection : Towards fault-tolerant neural networks
2022
Context: Machine learning has proved an efficient tool, but the systems need tools to mitigate risks during runtime. One approach is fault tolerance: detecting and handling errors before they cause harm. Objective: This paper investigates whether rare co-activations – pairs of usually segregated nodes activating together – are indicative of problems in neural networks (NN). These could be used to detect concept drift and flagging untrustworthy predictions. Method: We trained four NNs. For each, we studied how often each pair of nodes activates together. In a separate test set, we counted how many rare co-activations occurred with each input, and grouped the inputs based on whether its class…