Search results for " validation"
showing 10 items of 313 documents
Calibration and Validation of Algorithms for the Estimation of Chlorophyll-A in Inland Waters with Sentinel-2
2018
The Ocean Color 2 (OC2), Ocean Color 3 (OC3) and Dall'Olmo three-band (TBDO) algorithms used for the estimation of the chlorophyll-a concentration [Chl-a] have been calibrated and validated for Sentinel-2 spectral bands. Measurements of in situ chlorophyll-a, radiometry and simulations with HydroLight have been used for this purpose within the Ecological Status of AQuatic Systems Satellites (ESAQS) Project to estimate water quality in aquatic systems in Spain. The results show that Sentinel-2 spectral bands are suitable for studying the chlorophyll-a concentration in inland waters. The TBDO algorithm have been applied to Sentinel-2 images and satisfactory results have been obtained in Albuf…
Validação de um questionário de satisfação sobre a formação prática de estudantes de enfermagem
2019
Objetivo: validar un instrumento para valorar la formación práctica y la satisfacción con las asignaturas de Practicum de los estudiantes de Enfermería. Método: estudio observacional, descriptivo, transversal (curso 2014-2015). Validación de un cuestionario autoadministrado y anónimo (17 ítems) de Satisfacción sobre el Practicum en Estudiantes de Enfermería, elaborado por consenso de ocho expertos en formación práctica (en tres sesiones de grupo nominal). Se realizó análisis factorial y confirmatorio, estimándose la consistencia interna para determinar su validez. Se calculó la satisfacción de los estudiantes en cada asignatura y en su totalidad. Resultados: 174 respuestas. Alta correlación…
Experimental validation of optimisation strategies in hydroforming of T-shaped tubes
2008
For three dimensional tube hydroforming operations (i.e. T or Y shaped tubes) the calibration of both material feeding history and internal pressure path during the process is crucial and many approaches to such optimization were presented; the authors developed some procedures to optimize pressure paths and punch velocity histories with the application of an integrated method FEM - Gradient based optimization tools. In this paper, an experimental validation campaign of the utilized optimization strategies is presented with the aim to assess the effectiveness of the developed procedures. An optimization procedure (gradient based techniques) was applied on the process parameters leading to t…
Experimental characterization and comparison of TLIM performances with different primary winding connections
2017
Abstract This paper presents an experimental characterization and comparison of the performances achieved by a Tubular Linear Induction Motor (TLIM) prototype with different typologies of primary winding connections. More in detail, three different configurations have been considered, analyzed and discussed: full-pitch star, 5/6 shortened pitch star and 5/6 shortened pitch double star. For this purpose, an experimental test bench at the Sustainable Development and Energy Saving Laboratory (SDESLab), University of Palermo, Italy, has been set-up. The obtained results have allowed the identification of the best winding configuration for different applications intended for the motor. Moreover,…
Experimental validation of a distribution theory based analysis of the effect of manufacturing tolerances on permanent magnet synchronous machines
2017
An experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor is presented in this paper. The performances that have been investigated are: cogging force, end effect cogging force and generated thrust. It is demonstrated that: 1) the statistical variability of the magnets introduces harmonics in the spectrum of the cogging force; 2) the value of the end effect cogging force is directly linked to the values of then remanence field of the external magnets placed on the slider; 3) the generated thrust and its statistical distribution depend on the remanence field of the magnets placed on the translator.
Contribution to the study of the recovery of wast heat : study and optimization of Stirling engines
2012
Several machines currently used, internal combustion engines for the car industry or thermal power plants in energy, exhaust a considerable amount of heat. Generally this heat is dispersed in the atmosphere and its energy lost. So we took a special interest in external heat engines which primary energy is heat energy, and more particularly in Stirling engines. One of its main characteristics is the used of energy from heat produced externally like energy source. This allows Stirling engines to be multi-fuel and even to use natural heat energy.The study carried out is made up of two parts. First, a three zones zero dimensional finite-time thermodynamic model has been developed. It takes into…
Detecting informative higher-order interactions in statistically validated hypergraphs
2021
Recent empirical evidence has shown that in many real-world systems, successfully represented as networks, interactions are not limited to dyads, but often involve three or more agents at a time. These data are better described by hypergraphs, where hyperlinks encode higher-order interactions among a group of nodes. In spite of the large number of works on networks, highlighting informative hyperlinks in hypergraphs obtained from real world data is still an open problem. Here we propose an analytic approach to filter hypergraphs by identifying those hyperlinks that are over-expressed with respect to a random null hypothesis, and represent the most relevant higher-order connections. We apply…
Adaptation of the Body Image after Breast Cancer Questionnaire in the Polish context: factorial structure and validity of the scale
2016
<b>Background</b><br /> Valid assessment of body image is salient in therapy and rehabilitation of women suffering from breast cancer. Adequate instruments are still lacking in this domain. To overcome this limitation two aims were formulated in the study. First, we tested the factorial structure of the Body Image after Breast Cancer Questionnaire (BIBCQ) developed by Baxter (1998) in Canada, in the Polish context. Then, we tested the construct validity of the scale. The scale is based on a multidimensional concept of the body image of chronically ill individuals proposed by Vamos (1993).<br /> <br /> <b>Participants and procedure</b><br /> A …
Refitting of an eco-friendly sailing yacht: numerical prediction and experimental validation
2016
A 4.60 m sailing yacht, made with a flax fiber composite and wood, has been refitted with the aim of hull weight reduction and performance improvement during regattas. The first objective was obtained with a lightening of internal hull reinforcements while the second one with a reduction of the maximum beam, in order to minimize the longitudinal moment of inertia. The refitting was first simulated via CAD-FEM interaction to establish the feasibility of the procedure and to verify the structural integrity. The resulting hull was then instrumented with strain gauges and tested under typical rigging and sailing conditions. Results obtained by the numerical modeling and measured from experiment…
Investigating Limits in Exploiting Assembled Landslide Inventories for Calibrating Regional Susceptibility Models: A Test in Volcanic Areas of El Sal…
2022
This research is focused on the evaluation of the reliability of regional landslide susceptibility models obtained by exploiting inhomogeneous (for quality, resolution and/or triggering related type and intensity) collected inventories for calibration. At a large-scale glance, merging more inventories can result in well-performing models hiding potential strong predictive deficiencies. An example of the limits that such kinds of models can display is given by a landslide susceptibility study, which was carried out for a large sector of the coastal area of El Salvador, where an apparently well-performing regional model (AUC = 0.87) was obtained by regressing a dataset through multivariate ad…