We study estimation and prediction of Gaussian random fields with covariance models belonging to the generalized Wendland (GW) class, under fixed domain asymptotics. As for the Matérn case, this class allows for a continuous parameterization of smoothness of the underlying Gaussian random field, being additionally compactly supported. The paper is divided into three parts: first, we characterize the equivalence of two Gaussian measures with GW covariance function, and we provide sufficient conditions for the equivalence of two Gaussian measures with Matérn and GW covariance functions. In the second part, we establish strong consistency and asymptotic distribution of the maximum likelihood estimator of the microergodic parameter associated to GW covariance model, under fixed domain asymptotics. The third part elucidates the consequences of our results in terms of (misspecified) best linear unbiased predictor, under fixed domain asymptotics. Our findings are illustrated through a simulation study: the former compares the finite sample behavior of the maximum likelihood estimation of the microergodic parameter with the given asymptotic distribution. The latter compares the finitesample behavior of the prediction and its associated mean square error when using two equivalent Gaussian measures with Matérn and GW covariance models, using covariance tapering as benchmark.1 imsart-aos ver.

we consider a new operator acting on rescaled weighted differences between two members of the class Φ d of positive definite radial functions. In particular, we study the positive definiteness of the operator for the Matérn, Generalized Cauchy and Wendland families.

Using theoretical arguments, we present two novel spectrum models of the streamwise velocity component with robust correlation structures, which account for and decouple the fractal dimension and Hurst effect. The formulations that use isotropic concepts are adapted from the modern probability theory using the so-called generalized Cauchy and Dagum models, which belong to wide-sense-stationary random fields. A complementary inspection of these two models with field data from a met-tower-mounted sonic anemometer located within the atmospheric surface layer reveals good agreement and better performance than other conventionally used isotropic-based models of streamwise velocity spectra. The fractal dimension, D, of both models is consistent with the well-known Kolmogorov −5/3 power law in the inertial sub-range. For completeness, the study includes a derivation of the explicit forms of the energy spectral densities of the Cauchy and Dagum covariances.

<p>Este artículo muestra las etapas de validación de una escala de evaluación del impacto de la investigación educativa en la práctica docente, enfatizando los procedimientos de validez del constructo subyacente. Para ello, se tuvieron en consideración el problema a investigar y los criterios de rigor científico propios de la construcción de instrumentos de encuesta, concretamente la escala de evaluación. Operando con datos procedentes de tal escala aplicada a una muestra de 62 docentes universitarios y 117 docentes no universitarios de Granada (España), mediante un análisis secundario de datos, se desarrollan las diferentes etapas de validación de constructo; obteniéndose tres constructos representados por 16 sentencias (ítems) de los 43 inicialmente disponibles.</p>El estudio muestra la potencialidad del análisis factorial confirmatorio frente a la debilidad del exploratorio en la indagación de la validez de constructo de un instrumento de medida con variables ordinales, cual es la escala de valoración, y, al par, en la reducción de ítems de la misma.<p> </p>

En este artículo se abordarán dos temas relevantes; el primero de ellos se refiere a las causas que explicarían el bajo impacto de la investigación educativa (IE) en la práctica docente (PD) y el segundo, relacionado con la generación de un índice que mida el impacto que tiene la investigación sobre la docencia usando el índice de Fornell. Para lo anterior, se contempló una muestra de 179 individuos, 62 universitarios y 117 docentes no universitarios. Mediante un análisis secundario, y producto de la utilización de ecuaciones estructurales, se identifica un modelo que mostró que la percepción sobre el diagnóstico del impacto de la investigación educativa sobre la práctica de los docentes (IE-PD), explicaba en forma directa la comprensión del fenómeno impacto. El índice de impacto de la IE-PD fue de un 60,23% en contra, que muestra una tendencia de los docentes a considerar no sustantivo el aporte de la Investigación Educativa para su práctica docente. This article will discuss two important subjects. The first is the model of the impact of educational research on teaching practice. The second is the creation of an index that measures the impact of educational research on teaching practice, using structural equation modeling. This study looked at a sample of 179 individuals, of which 62 were university teachers and 117 were non-university teachers. Through a secondary analysis of the data, the different stages of construct validity were developed and structural equation modeling, obtaining a model covered by three constructs represented by 15 items. The model showed that the perception of the diagnosis of the impact of educational research on the practice of teachers directly explained the understanding of the impact phenomenon. The impact index EI-PD was 60.23%, showing that teachers do not substantially consider the contribution of educational research on teaching practice.