Search results for "validation"
showing 10 items of 620 documents
A Large-Scale Empirical Evaluation of Cross-Validation and External Test Set Validation in (Q)SAR.
2013
(Q)SAR model validation is essential to ensure the quality of inferred models and to indicate future model predictivity on unseen compounds. Proper validation is also one of the requirements of regulatory authorities in order to accept the (Q)SAR model, and to approve its use in real world scenarios as alternative testing method. However, at the same time, the question of how to validate a (Q)SAR model, in particular whether to employ variants of cross-validation or external test set validation, is still under discussion. In this paper, we empirically compare a k-fold cross-validation with external test set validation. To this end we introduce a workflow allowing to realistically simulate t…
Thermal simulation of a power transformer
2019
In the article we propose a method of thermally constructive optimization of a 110/20 kV power transformer by numerical simulation (by the finite element method) of the thermal field in the transformer. The thermal simulation was done in the Comsol module called Heat Transfer Module, based on the documentation in Catia V5, and the experimental validation was done by thermography.
A Simple Cluster Validation Index with Maximal Coverage
2017
Clustering is an unsupervised technique to detect general, distinct profiles from a given dataset. Similarly to the existence of various different clustering methods and algorithms, there exists many cluster validation methods and indices to suggest the number of clusters. The purpose of this paper is, firstly, to propose a new, simple internal cluster validation index. The index has a maximal coverage: also one cluster, i.e., lack of division of a dataset into disjoint subsets, can be detected. Secondly, the proposed index is compared to the available indices from five different packages implemented in R or Matlab to assess its utilizability. The comparison also suggests many interesting f…
Analysis a DSP Implementation and Experimental Validation of a Loss Minimization Algorithm Applied to Permanent Magnet Synchronous Motor Drives
2004
In this paper a new loss minimization control algorithm for inverter-fed permanent-magnet synchronous motors (PMSM), which allows to reduce the power losses of the electric drive without penalty on its dynamic performances, is analyzed, experimentally realized and validated. In particular, after a brief recall of two loss minimization control strategies (the "search control" and the "loss-model control"), both a modified dynamic model of the PMSM, which takes into account the iron losses, and a "loss-model" control strategy, are treated. Experimental tests on a specific PMSM drive employing the proposed loss minimization algorithm were performed aiming to validate the actual implementation.…
Propiedades psicométricas y estructura factorial del BRCS en una muestra de personas mayores españolas
2015
Successful resilience is a variable often related to an optimal ag-ing process. However, literature is rather limited when dealing with assess-ment instruments for the elderly in the Spanish language. The objective of this work is to validate the Brief Resilient Coping Scale (Sinclair & Wallston, 2004), a four item likert scale, in the Spanish elderly. For this propose, the scale was administrated to a sample of 991 elderly Spanish participants, and the data set analysed in terms of exploratory and confirm-atory factor analysis, internal consistency and criterion validity. The scale demonstrated good psychometric properties. Furthermore, the homogenei-ty indices were higher than the recentl…
Evaluation of a Support Vector Machine Based Method for Crohn’s Disease Classification
2019
Crohn’s disease (CD) is a chronic, disabling inflammatory bowel disease that affects millions of people worldwide. CD diagnosis is a challenging issue that involves a combination of radiological, endoscopic, histological, and laboratory investigations. Medical imaging plays an important role in the clinical evaluation of CD. Enterography magnetic resonance imaging (E-MRI) has been proven to be a useful diagnostic tool for disease activity assessment. However, the manual classification process by expert radiologists is time-consuming and expensive. This paper proposes the evaluation of an automatic Support Vector Machine (SVM) based supervised learning method for CD classification. A real E-…
A Confirmatory Factor Analysis of the “Autoconcepto Forma 5” Questionnaire in Young Adults from Spain and Chile
2011
The aim of this work is to examine the pentafactorial validity of the AF5 Self-Concept Questionnaire in Spanish and Chilean young adults. From the responses of a total of 4,383 young adults aged 17 to 22 years (1,918 Spanish, 44%, and 2,465 Chilean, 56%) it was analyzed the reliability of the instrument, the compared validity of the 5 oblique factor model proposed by the authors versus the unifactorial and the orthogonal alternative models, and was studied the invariance of one Chilean sample. The results of confirmatory factor analyses supported the authors' pentafactorial model. The multi-group factorial invariance showed that Chilean sample of the AF5 does not change neither the Spanish …
Psychometric evaluation of the Finnish version of the impact on participation and autonomy questionnaire in persons with multiple sclerosis
2017
Objective: The objective of this study was to evaluate the psychometric properties of the impact on participation and autonomy (IPA) questionnaire. The Finnish version of IPA (IPAFin) was translated into Finnish using the protocol for linguistic validation for patient-reported outcomes instruments. Methods: A total of 194 persons with multiple sclerosis (MS) (mean age 50 years SD 9, 72% female) with moderate to severe disability participated in this study. A confirmatory factor analysis (CFA) was used to confirm the four factor structure of the IPAFin. The work and educational opportunities domain was excluded from analysis, because it was only applicable to 51 persons. Internal consistency…
Satisfacción de las mujeres con la experiencia del parto: validación de la Mackey Satisfaction Childbirth Rating Scale
2012
ResumenObjetivosDeterminar la fiabilidad y validez de contenido y concepto de la Mackey Childbirth Satisfaction Rating Scale, escala para medir la satisfacción de las mujeres con el parto y el nacimiento.MétodosSe utilizó el método de traducción-retrotraducción para obtener una versión adaptada de la escala. Para la validación se seleccionó una muestra de 325 mujeres que habían tenido un hijo sano mediante parto vaginal. La recogida de datos se realizó con un cuestionario autocumplimentado que incluía la escala adaptada, expectativas ante el parto y variables obstétricas y sociodemográficas. Se valoró la fiabilidad en una submuestra de 45 mujeres que cumplimentaron de nuevo la escala a los …
Applying a Data Quality Model to Experiments in Software Engineering
2014
Data collection and analysis are key artifacts in any software engineering experiment. However, these data might contain errors. We propose a Data Quality model specific to data obtained from software engineering experiments, which provides a framework for analyzing and improving these data. We apply the model to two controlled experiments, which results in the discovery of data quality problems that need to be addressed. We conclude that data quality issues have to be considered before obtaining the experimental results.