Search results for "Erk"

k-Step shape estimators based on spatial signs and ranks

2010

In this paper, the shape matrix estimators based on spatial sign and rank vectors are considered. The estimators considered here are slight modifications of the estimators introduced in Dümbgen (1998) and Oja and Randles (2004) and further studied for example in Sirkiä et al. (2009). The shape estimators are computed using pairwise differences of the observed data, therefore there is no need to estimate the location center of the data. When the estimator is based on signs, the use of differences also implies that the estimators have the so called independence property if the estimator, that is used as an initial estimator, has it. The influence functions and limiting distributions of the es…

Tests and estimates of shape based on spatial signs and ranks

2009

Nonparametric procedures for testing and estimation of the shape matrix in the case of multivariate elliptic distribution are considered. Testing for sphericity is an important special case. The tests and estimates are based on the spatial sign and rank covariance matrices. The estimates based on the spatial sign covariance matrix and symmetrized spatial sign covariance matrix are Tyler's [A distribution-free M-estimator of multivariate scatter, Ann. Statist. 15 (1987), pp. 234–251] shape matrix and and Dümbgen's [On Tyler's M-functional of scatter in high dimension, Ann. Inst. Statist. Math. 50 (1998), pp. 471–491] shape matrix, respectively. The test based on the spatial sign covariance m…

Dynamics analysis of distributed parameter system subjected to a moving oscillator with random mass, velocity and acceleration

2002

Abstract The problem of calculating the response of a distributed parameter system excited by a moving oscillator with random mass, velocity and acceleration is investigated. The system response is a stochastic process although its characteristics are assumed to be deterministic. In this paper, the distributed parameter system is assumed as a beam with Bernoulli–Euler type analytical behaviour. By adopting the Galerkin's method, a set of approximate governing equations of motion possessing time-dependent uncertain coefficients and forcing function is obtained. The statistical characteristics of the deflection of the beam are computed by using an improved perturbation approach with respect t…

A symmetric BEM approach to strain gradient elasticity for 2D static boundary-value problems

2014

The symmetric Galerkin Boundary Element Method is used to address a class of strain gradient elastic materials featured by a free energy function of the (classical) strain and of its (first) gradient. With respect to the classical elasticity, additional response variables intervene, such as the normal derivative of the displacements on the boundary, and the work-coniugate double tractions. The fundamental solutions - featuring a fourth order partial differential equations (PDEs) system - exhibit singularities which in 2D may be of the order 4 1/ r . New techniques are developed, which allow the elimination of most of the latter singularities. The present paper has to be intended as a resear…

Strain gradient elasticity within the SGBEM

2014

Value Creation and Power Asymmetries in Digital Ecosystems : A Study of a Cloud Gaming Provider

2020

Digital platforms connecting users and service providers have a central role in determining the value creation structure of ecosystems. Platform developers try to achieve a dominant position for the platform with a strong ecosystem around it. The size and attractiveness of the services can attract new users, and growing user volume can bring new co-operative service providers to the service partner network. An interesting question is how the presence of power and potential power asymmetry affect the value creation capability and the structure of a network around a platform? This chapter describes an example of value creation and the influence of power asymmetry in a digital ecosystem built …

Deep learning approach for prediction of impact peak appearance at ground reaction force signal of running activity

2020

Protruding impact peak is one of the features of vertical ground reaction force (GRF) that is related to injury risk while running. The present research is dedicated to predicting GRF impact peak appearance by setting a binary classification problem. Kinematic data, namely a number of raw signals in the sagittal plane, collected by the Vicon motion capture system (Oxford Metrics Group, UK) were employed as predictors. Therefore, the input data for the predictive model are presented as a multi-channel time series. Deep learning techniques, namely five convolutional neural network (CNN) models were applied to the binary classification analysis, based on a Multi-Layer Perceptron (MLP) classifi…

The Influence of Social Vision, Social Networks, and Financial Return on Social SME Sustainability

2020

Social entrepreneurship is one of the catalysts of poverty reduction and sustainable development, but its impact in developing countries is not rapid in comparison to traditional entrepreneurship. The idea is to explain the phenomenon from an entrepreneurial perspective and to focus on entrepreneur sustainability. The data for this study was collected at the firm level with questionnaires through Qualtrics online survey platform. The structured questionnaires target the Social Micro, Small, and Medium-Sized Enterprises in Nigeria. This study provides a fundamental understanding of structural relationships that exist between the social vision, social network, financial return, innovation, an…

Sylviasta, Sylvialle, Sylviana : retoriikka ja merkityksenmuodostus osoitteessa www.sylviaplathforum.com

2016

This study explores the writings of Sylvia Plath Forum, a discussion forum in the Internet that was launched in 1998. Using Norman Fairclough’s critical discourse analysis, Chaïm Perelman’s theory of argumentation, Kenneth Burke’s idea of identification as the basis of rhetoric, and René Girards’s theory of mimetic desire as its framework this study looks into the forum’s meaning-making processes and the ways the author Sylvia Plath (1932-1963) and her readers are represented on the forum. Attention is paid especially to meaning-making practices that are connected with literary studies, feminism, medicalization, and cultic phenomena. Furthermore, cultic discourse and fan discourse are under…

A symmetric Galerkin BEM for plate bending analysis

2009

Abstract The Symmetric Galerkin Boundary Element Method is employed in thin plate bending analysis in accordance with the Love–Kirchhoff kinematical assumption. The equations are obtained through the stationary conditions of the total potential energy, written for a plate whose boundary is discretized in boundary elements. Since the matrix coefficients are made up as double integrals with high order singularities, a strategy is shown to compute these coefficients in closed form. Furthermore, in order to model the kinematical discontinuities and to weight the mechanical quantities along the boundary elements, the Lagrangian quadratic shape functions, rather than C 1 type (spline, Hermitian),…