Search results for "ongelmat"

Determining a Random Schrödinger Operator : Both Potential and Source are Random

2020

We study an inverse scattering problem associated with a Schr\"odinger system where both the potential and source terms are random and unknown. The well-posedness of the forward scattering problem is first established in a proper sense. We then derive two unique recovery results in determining the rough strengths of the random source and the random potential, by using the corresponding far-field data. The first recovery result shows that a single realization of the passive scattering measurements uniquely recovers the rough strength of the random source. The second one shows that, by a single realization of the backscattering data, the rough strength of the random potential can be recovered…

Nuorten vankien lapsuuden väkivaltakokemukset ja heidän vanhempiensa parisuhdeongelmat

1999

Perceived challenges living and integrating into Finnish society : A study among immigrants in Finland

2022

The number of immigrants living in Finland has significantly increased since the 1990s. It can be challenging to live and integrate into a new society. This study explores the challenges immigrants face living and integrating into Finnish society. Drawing on data collected from 103 immigrants living in Finland, this study shows that the challenges immigrants face integrating into Finnish society can be classified into four main categories: (1) language barrier, (2) discrimination in employment opportunities, (3) racism and inequality, and (4) fewer opportunities of integration. Implications and recommendations are briefly considered.

Guaranteed error bounds for a class of Picard-Lindelöf iteration methods

2013

We present a new version of the Picard-Lindelof method for ordinary dif- ¨ ferential equations (ODEs) supplied with guaranteed and explicitly computable upper bounds of an approximation error. The upper bounds are based on the Ostrowski estimates and the Banach fixed point theorem for contractive operators. The estimates derived in the paper take into account interpolation and integration errors and, therefore, provide objective information on the accuracy of computed approximations. peerReviewed

Work incapacity among family caregivers : a record linkage study

2022

BackgroundFamily caregiving-related physical and mental health problems may lead to work incapacity in employed caregivers. The aim of this study was to quantify sickness absences and disability pensions (SADP) among high-intensity family caregivers available to the labour market compared with a control population.MethodsThe study sample included all individuals in Finland, who had received caregiver’s allowance and were available to the labour market in 2012 (n=16 982) and their controls (n=35 371). Information on the number of sickness absence (spells >10 days) and disability pension (SADP) days and related diagnoses according to ICD-10 were obtained from national registers for the yea…

Radiating and non-radiating sources in elasticity

2018

In this work, we study the inverse source problem of a fixed frequency for the Navier's equation. We investigate that nonradiating external forces. If the support of such a force has a convex or non-convex corner or edge on their boundary, the force must be vanishing there. The vanishing property at corners and edges holds also for sufficiently smooth transmission eigenfunctions in elasticity. The idea originates from the enclosure method: The energy identity and new type exponential solutions for the Navier's equation.

Why Does Cultural Diversity Foster Technology-enabled Intergenerational Collaboration?

2019

Globalization and information technology enable people to join the movement of global citizenship and work without borders. However, different type of barriers existed that could affect collaboration in todays work environment, in which different generations are involved. Although researchers have identified several technical barriers to intergenerational collaboration (iGOAL), the influence of cultural diversity on iGOAL has rarely been studied. Therefore, using a quantitative study approach, this paper investigates the impact of differences in cultural background on perceived technical and operational barriers to iGOAL. Our study reveals six barriers to IGC that are perceived differently …

Free boundary methods and non-scattering phenomena

2021

We study a question arising in inverse scattering theory: given a penetrable obstacle, does there exist an incident wave that does not scatter? We show that every penetrable obstacle with real-analytic boundary admits such an incident wave. At zero frequency, we use quadrature domains to show that there are also obstacles with inward cusps having this property. In the converse direction, under a nonvanishing condition for the incident wave, we show that there is a dichotomy for boundary points of any penetrable obstacle having this property: either the boundary is regular, or the complement of the obstacle has to be very thin near the point. These facts are proved by invoking results from t…

Tensor tomography in periodic slabs

2018

Abstract The X-ray transform on the periodic slab [ 0 , 1 ] × T n , n ≥ 0 , has a non-trivial kernel due to the symmetry of the manifold and presence of trapped geodesics. For tensor fields gauge freedom increases the kernel further, and the X-ray transform is not solenoidally injective unless n = 0 . We characterize the kernel of the geodesic X-ray transform for L 2 -regular m -tensors for any m ≥ 0 . The characterization extends to more general manifolds, twisted slabs, including the Mobius strip as the simplest example.

Building up an ecologically sustainable and socially desirable post-COVID-19 future

2021

AbstractCOVID-19 crisis has emphasized how poorly prepared humanity is to cope with global disasters. However, this crisis also offers a unique opportunity to move towards a more sustainable and equitable future. Here, we identify the underlying environmental, social, and economic chronic causes of the COVID-19 crisis. We argue in favour of a holistic view to initiate a socio-economic transition to improve the prospects for global sustainability and human well-being. Alternative approaches to “Business-As-Usual” for guiding the transition are already available for implementation. Yet, to ensure a successful and just transition, we need to change our priorities towards environmental integrit…