Search results for "M function"

¿Cómo funciona el sistema de innovación del sector cerámico español?

2013

[EN]: In this article we apply the functions of innovation systems framework to assess its appropriateness to characterise the innovation activity of the tile industry in Castellón. This framework is based on idea that a well functioning innovation system requires that a number of key activities take place. If this occurs innovative output is higher. Our analysis provides a deeper understanding of the role of innovation as a strategic option in a mature industry in the context of globalisation. By applying this new theoretical approach to study innovation and highlighting the functions that the system requires, we shown the constraints, inertias, challenges and opportunities that the innova…

Utility of the Mantel-Haenszel Procedure for Detecting Differential Item Functioning in Small Samples

2004

Sample-size restrictions limit the contingency table approaches based on asymptotic distributions, such as the Mantel-Haenszel (MH) procedure, for detecting differential item functioning (DIF) in many practical applications. Within this framework, the present study investigated the power and Type I error performance of empirical and inferential criteria for DIF detection in small samples. Sample sizes (50/50, 100/50, 200/50, and 100/100 for the reference and focal groups, respectively), ability distributions (equal and unequal), and amount of DIF (moderate and high) were manipulated. The results show the advantages of employing theMHchi-square statistic using high levels of significance (•…

The MAST-FV/FE scheme for the simulation of thermohaline processes in variable density saturated porous media

2009

A novel methodology for the simulation of 2D thermohaline double diffusive processes, driven by heterogeneous temperature and concentration fields in variable-density satu- rated porous media, is presented. The stream function is used to describe the flow field and it is defined in terms of mass flux. The partial differential equations governing system is given by the mass conservation equation of the fluid phase written in terms of the mass- based stream function, as well as by the advection–diffusion transport equations of the contaminant concentration and of the heat. The unknown variables are the stream func- tion, the contaminant concentration and the temperature. The governing equatio…

The MAST-FV/FEM scheme for the simulation of thermohaline processes in density-variable saturated porous media

2008

Funcionamiento diferencial del ítem de la evaluación internacional PISA. Detección y comprensión

2014

Este trabajo analiza el funcionamiento diferencial del ítem (FDI) de la prueba de comprensión lectora de la evaluación PISA2000 entre la muestras del Reino Unido y España. Se estudian los ítems liberados con el fin de aunar las fases de detección del FDI con la comprensión de sus causas. En la fase de detección se comparan los resultados de los procedimientos Mantel-Haenszel, Regresión Logística y Medias Estandarizadas en sus versiones para ítems dicotómicos y politómicos. Los resultados muestran que dos ítems presentan funcionamiento diferencial aunque el estudio post-hoc llevado a cabo sobre su contenido no ha podido precisar sus causas.

Rasch Analysis of Authentic Evaluation of Young Children's Functioning in Classroom Routines.

2021

This study evaluated the functioning of children in early childhood education classroom routines, using the 3M Functioning in Preschool Routines Scale. A total of 366 children aged 36 to 70 months and 22 teachers from six early childhood education centers in Spain participated in the study. The authors used the Rasch model to determine the item fit and the difficulty of the items in relation to children's ability levels in this age range. The Rasch Differential Item Functioning (DIF) analysis by child age groups showed that the item difficulty differed according to the children's age and according to their levels of competence. The results of this study supported the reliability and validit…

Liberal and Conservative Differential Item Functioning Detection Using Mantel-Haenszel and SIBTEST: Implications for Type I and Type II Error Rates

2004

The aim of this work was to determine, in terms of Type I and Type II error rates, the risks of applying various statistical procedures for evaluating differential item functioning. To this end, the authors carried out a simulation study in which the Mantel-Haenszel and SIBTEST procedures were applied in conjunction. The variables manipulated were sample size and distribution of ability between groups. Results indicated that, although there was a high rate of agreement between the procedures, the joint Type I and Type II error rate may vary substantially from that obtained when each of the procedures was applied separately. Furthermore, the authors analyzed empirical data to obtain informat…

Monte Carlo simulation for the response analysis of long-span suspended cables under wind loads

2004

This paper presents a time-domain approach for analyzing nonlinear random vibrations of long-span suspended cables under transversal wind. A consistent continuous model of the cable, fully accounting for geometrical nonlinearities inherent in cable behavior, is adopted. The effects of spatial correlation are properly included by modeling wind velocity fluctuation as a random function of time and of a single spatial variable ranging over cable span, namely as a one-variate bi-dimensional (1V-2D) random field. Within the context of a Galerkin`s discretization of the equations governing cable motion, a very efficient Monte Carlo-based technique for second-order analysis of the response is prop…

Contribution to the platoon distribution analysis in steady-state traffic conditions

2014

The traffic flow analysis and the relevant vehicle distribution (“free-moving” or “platooned” vehicles) on highway facilities at uninterrupted flow has always had fundamental importance in Highway Engineering, with special reference to topics like traffic operations, car accidents, road safety and air pollution emissions. In light of this, the study suggests a calculation algorithm as a random test generator to simulate a steady state traffic flow and to provide time headways. Thanks to the outcome produced by numerical simulations, we analysed platoon distributions within traffic flows in a steady-state regime and showed the results of numerical analyses carried out by traffic random proce…

Item response theory and differential test functioning analysis of the HBSC-Symptom-Checklist across 46 countries

2022

Abstract Background The Symptom Checklist (SCL) developed by the Health Behaviour in School-aged Children (HBSC) study is a non-clinical measure of psychosomatic complaints (e.g., headache and feeling low) that has been used in numerous studies. Several studies have investigated the psychometric characteristics of this scale; however, some psychometric properties remain unclear, among them especially a) dimensionality, b) adequacy of the Graded Response Model (GRM), and c) measurement invariance across countries. Methods Data from 229,906 adolescents aged 11, 13 and 15 from 46 countries that participated in the 2018 HBSC survey were analyzed. Adolescents were selected using representative s…