Search results for "ESOL"
showing 10 items of 2444 documents
Los modelos de enseñanza de los problemas de aligación en las enciclopedias escolares españolas
2021
Los problemas de aligación forman parte de las matemáticas desde épocas antiguas. Actualmente, han perdido interés educativo, aunque siguen presentes en los temas de álgebra y en la vida diaria. En este trabajo, presentamos el modelo de enseñanza de estos problemas en las enciclopedias escolares que estuvieron vigentes desde los años veinte hasta los años setenta del pasado siglo. Para poder caracterizar el modelo de enseñanza nos fijamos en los aspectos contextuales, los estructurales, los procedimentales y los organizativos de los problemas de aligación. Realizamos una clasificación de los tipos de problemas, de los contextos utilizados, de los métodos de resolución que se utilizaban y có…
Linear spectral mixture modelling to estimate vegetation amount from optical spectral data
1996
Abstract Spectral mixture modelling has developed in recent years as a suitable remote sensing tool for analysing the biophysical and compositional character of ground surfaces. In this paper the potentiality of the linear spectral mixture model to extract vegetation related parameters from 0·4-2·5 μm reflectance data has been tested. High spectral resolution reflectance measurements of soil-plant mixtures with different soil colour and plant densities were carried out in a laboratory experiment. The constrained least-squares and the factor analysis unmixing procedures were applied to generate endmember fractions of the components present in the mixtures and to test the validity of the mode…
Electron-spectroscopic investigations on ternary HFS: CeT2X2
1997
Investigations of the electronic properties were carried out for ternary Ce-based heavy fermion systems. The well-ordered surfaces of HFS were prepared by MBE on W (110) with subsequent annealing. The layers are characterised by MEED, LEED, AES and XPS. For the electron-spectroscopic investigations, ARUPS and SPEELS were used. In the photoemission spectra, dispersion effects could be detected. By means of SPEELS, the dipole-forbidden Ce f-f transitions could be observed. The comparison of the energy loss spectra above and below the characteristic temperature T∗ reveals differences in the energy losses as well as in the asymmetries.
Comparison of different sets of array configurations for multichannel 2D ERT acquisition
2017
Abstract Traditional electrode arrays such Wenner-Schlumberger or dipole-dipole are still widely used thanks to their well-known properties but the array configurations are generally not optimized for multi-channel resistivity measures. Synthetic datasets relating to four different arrays, dipole-dipole (DD), pole-dipole (PD), Wenner-Schlumberger (WS) and a modified version of multiple gradient (MG), have been made for a systematic comparison between 2D resistivity models and their inverted images. Different sets of array configurations generated from simple combinations of geometric parameters (potential dipole lengths and dipole separation factors) were tested with synthetic and field dat…
A DSP-Based Resolver-To-Digital Converter for High-Performance Electrical Drive Applications
2016
This paper presents a low cost, simple, and highly accurate resolver-to-digital converter (RDC) for electrical drive applications based on an integrated software approach, thus allowing a significant reduction of hardware components count with significant improvements in terms of reliability, reduction of fault rate, and susceptibility to electromagnetic interference (EMI). Particular attention has been addressed to cost which is 25% off over conventional RDC. Simulations and experimental tests confirm the high quality of the proposed system.
A set of indicators for arc faults detection based on low frequency harmonic analysis
2016
In this paper a novel set of indicators is presented for arc faults detection in electrical circuits. The indicators are defined starting from an experimental characterization of the arc fault phenomenon and the study of the arcing current in several test conditions, which were chosen in accordance with the UL 1699 Standard requirements. The proposed parameters are measured by means of a high resolution low frequency spectral analysis of the arcing current, which allows to achieve a good spectral resolution even with short observation windows.
Filling defects in a ceramics forming process
1997
Publisher Summary This paper presents a simple semi-heuristic method to predict mold filling defects in a porcelain forming process. It involves both a mechanical modelling of this process as a squeezing flow, and a postprocessing calculus that unable a defects prediction as soon as the shape and the size of artistic reliefs are known. This shape analysis is carried out with a multi resolution wavelet analysis. The chapter models the filling stage and to propose a criterium to avoid any filling defect that could waste the quality of the drawings. It illustrates a simplified modelling of the process during which the “turning” stage is approximated by the deformation under pressure of a Norto…
Atomic resolution imaging of beryl: an investigation of the nano-channel occupation
2016
(C) 2016 The Authors. Journal of Microscopy published by JohnWiley & Sons, Ltd on behalf of the Royal Microscopical Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Conclusions from the Evaluation of Virtual Machine Based High Resolution Display Wall System
2016
There are several approaches to the construction of large scale high resolution display walls depending on the required use case. Some require support of 3D acceleration APIs like OpenGL, some require stereoscopic projection. Others simply require a surface with a very high display resolution. The authors of this paper have developed a virtual machine based high resolution display wall architecture that works for all planar projection use cases and does not require a custom integration. The software that generates the presented content is executed in a virtual machine thus no specific APIs other than those of the virtualized OS are required. Any software that is able to run under a given OS…