Search results for "large scale"

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Measuring D_A and H at z=0.57 from the Baryon Acoustic Peak in th…

2014

We present measurements of the angular diameter distance to and Hubble parameter at z = 0.57 from the measurement of the baryon acoustic peak in the correlation of galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey. Our analysis is based on a sample from Data Release 9 of 264 283 galaxies over 3275 square degrees in the redshift range 0.43 z DA(0.57) = 1408 ± 45 Mpc and H(0.57) = 92.9 ± 7.8 km s-1 Mpc-1 for our fiducial value of the sound horizon. These results from the anisotropic fitting are fully consistent with the analysis of the spherically averaged acoustic peak position presented in Anderson et al. Our distance measurements are a close match to th…

Ultrafast Optical Demagnetization manipulates Nanoscale Spin Structure in Domain Walls

2012

During ultrafast demagnetization of a magnetically ordered solid, angular momentum has to be transferred between the spins, electrons, and phonons in the system on femto- and picosecond timescales. Although the intrinsic spin-transfer mechanisms are intensely debated, additional extrinsic mechanisms arising due to nanoscale heterogeneity have only recently entered the discussion. Here we use femtosecond X-ray pulses from a free-electron laser to study thin film samples with magnetic domain patterns. We observe an infrared-pump-induced change of the spin structure within the domain walls on the sub-picosecond timescale. This domain-topography-dependent contribution connects the intrinsic dem…

Sequential Learning with LS-SVM for Large-Scale Data Sets

2006

We present a subspace-based variant of LS-SVMs (i.e. regularization networks) that sequentially processes the data and is hence especially suited for online learning tasks. The algorithm works by selecting from the data set a small subset of basis functions that is subsequently used to approximate the full kernel on arbitrary points. This subset is identified online from the data stream. We improve upon existing approaches (esp. the kernel recursive least squares algorithm) by proposing a new, supervised criterion for the selection of the relevant basis functions that takes into account the approximation error incurred from approximating the kernel as well as the reduction of the cost in th…

Large-scale network functional interactions during distraction and reappraisal in remitted bipolar and unipolar patients.

2017

Objectives The human brain is organized into large-scale networks that dynamically interact with each other. Extensive evidence has shown characteristic changes in certain large-scale networks during transitions from internally directed to externally directed attention. The aim of the present study was to compare these context-dependent network interactions during emotion regulation and to examine potential alterations in remitted unipolar and bipolar disorder patients. Methods We employed a multi-region generalized psychophysiological interactions analysis to quantify connectivity changes during distraction vs reappraisal pair-wise across 90 regions placed throughout the four networks of i…

A new large scale laboratory: The LEDA research centre (Laboratory of Earthquake engineering and Dynamic Analysis)

2017

Recently, the field of earthquake engineering experienced substantial enhancements due to numerous results of experimental and theoretical researches. Modern technical codes recognized the last advances in this field and provided new solutions for the structural assessment and design of buildings. However, the need for large scale testing is still taking several open questions, especially for the design of civil infrastructures, and experimental activity on full scale specimens has become necessary. This paper presents the main testing facilities of a new research centre, namely the Laboratory of Earthquake engineering and Dynamic Analysis (LEDA) of the University of Enna “Kore”. In particu…

The reaction structure of the LEDA research centre: Development and design

2017

In the last twenty years, the field of earthquake engineering experienced a noticeable improvement. The results of experimental and theoretical researches have contributed to the development of modern technical codes, which provide innovative solutions for the structural assessment and new design approaches. Despite this large amount of improvements, several open questions are still open, and the need for large scale testing has been deeply proved and discussed. A new research facility, namely the Laboratory of Earthquake engineering and Dynamic Analysis (LEDA), has been recently completed at the University of Enna "Kore". This research centre, funded with a grant from Italian Ministry of E…

Hierarchical-ACA DBEM for anisotropic three-dimensional time-domain fracture mechanics

2012

Hierarchical fast BEM for anisotropic time-harmonic 3-D elastodynamics

2012

The paper presents a fast boundary element method for anisotropic time-harmonic 3-D elastodynamic problems. The approach uses the hierarchical matrices format and the ACA algorithm for the collocation matrix setup and a preconditioned GMRES solver for the solution. The development of this approach for the anisotropic case presents peculiar aspects which deserve investigation and are studied in the paper leading to the employed computational strategy and its effective tuning. Numerical experiments are presented to assess the method accuracy, performances and numerical complexity. The method ensures adequate accuracy allowing remarkable reductions in computation time and memory storage.

THE RELATIONSHIP BETWEEN CIVIC FACTORS AND THE MIDDLE PROFICIENCY LEVEL OF CIVIC KNOWLEDGE

2021

This study explores the relationship between civic and citizenship factors and the middle proficiency level of students’ civic knowledge in the Baltic countries: Estonia, Latvia and Lithuania. The study uses large scale data from the IEA’s International Civic and Citizenship Education Study (ICCS) 2016. According to ICCS 2016, 39% of students from the three Baltic countries and only 26% of students from the Nordic countries had a middle proficiency level of civic knowledge. This middle proficiency level is the largest group in comparison to other levels. Therefore, the study aims to recognise the differences between the highest and lowest achievements in the middle proficiency level of civi…

Rapid acoustic boundary element method for solution of 3D problems using hierarchical adaptive cross approximation GMRES approach

2009

This paper presents a new solver for 3D acoustic problems called RABEM (Rapid Acoustic Boundary Element Method). The Adaptive Cross Approximation and a Hierarchical GMRES solver are used to generate both the system matrix and the right hand side vector by saving storage requirement, and to solve the system solution. The potential and the particle velocity values at selected internal points are evaluated using again the Adaptive Cross Approximation (ACA). A GMRES without preconditioner and with a block diagonal preconditioner are developed and tested for low and high frequency problems. Different boundary conditions (i.e. Dirichlet, Neumann and mixed Robin) are also implemented. Herein the p…