Search results for "Statistics and Probability"

The Calderón problem for the conformal Laplacian

2022

We consider a conformally invariant version of the Calderón problem, where the objective is to determine the conformal class of a Riemannian manifold with boundary from the Dirichlet-to-Neumann map for the conformal Laplacian. The main result states that a locally conformally real-analytic manifold in dimensions can be determined in this way, giving a positive answer to an earlier conjecture [LU02, Conjecture 6.3]. The proof proceeds as in the standard Calderón problem on a real-analytic Riemannian manifold, but new features appear due to the conformal structure. In particular, we introduce a new coordinate system that replaces harmonic coordinates when determining the conformal class in a …

Measuring the perceived value of rural tourism: a field survey in the western Sicilian agritourism sector

2016

Rural tourism constitutes a valuable tool for the sustainable development of many rural areas. This paper examines the concept of perceived value in rural tourism. A quantitative field survey was carried out in some main Western Sicilian holiday farms (agritourisms) during the Spring 2014. A theoretical model of the tourists’ perceived value in this specific context was developed and validated, using a 22-item scale. Using Partial Least Squares Path Modelling a theoretical structural model of the multidimensional structure of the RTPV was tested, assessing intensity and direction of the causal relationships among RTPV and its dimensions. Five dimensions were identified as forming the constr…

Differences between students' PISA reading literacy scores and grading for mother tongue and literature at school : A geostatistical analysis of the …

2016

In Finland, the national Core Curriculum for Basic Education defines the learning objectives along with the numerical grade to be given for good competence in each school subject in the final phase of basic education. While serving as a guideline for schools and teachers, it should also ensure an objective evaluation of all students in Finland. In this paper, we take a closer look at the equality of student assessment in Finland in the light of student performance in the Programme for International Student Assessment (PISA) 2009. This study investigates the relationship between the grades given to students in mother tongue and literature at different schools and the same students’ reading l…

Riskien havainnollistamisohjelmisto RiskDemo

2018

RiskDemo on vapaasti käytettävä ohjelmistotyökalu, joka on tarkoitettu havainnollistamaan riskejä todennäköisyyslaskennan ja tilastotieteen näkökulmasta. Ohjelmalla voidaan havainnollistaa riskejä monenlaisten graafisten esitysten, taulukoiden ja riskilukujen avulla. Tällä hetkellä sillä voidaan havainnollistaa demografiaa, korko- ja osakesijoittamista sekä klassista vararikkoteoriaa. Tässä artikkelissa esitellään RiskDemo-ohjelmiston ominaisuudet ja opastetaan sen käyttämiseen riskien havainnollistamisessa. Lukija voi RiskDemon avulla tutustua moniin riskienhallinnan avainkäsitteisiin havainnollisessa ja konkreettisessa muodossa. peerReviewed

Omission of Causal Indicators: Consequences and Implications for Measurement – A Rejoinder

2016

Univariate and multivariate properties of wind velocity time series

2009

We analyze the time series of hourly average wind speeds measured at 29 different stations located in Sicily, a region with a complex morphology. The investigation, performed from the univariate as well as the multivariate point of view, evidences that the statistical properties of wind at the single sites have features that are not reproduced by standard models and, thus, require specific modeling. Moreover, the synchronous evolution of wind velocity presents a cluster structure, obtained with different algorithms, that persists in the standard deviation too.