Search results for "Fitting"
showing 10 items of 225 documents
Risk of failure for the salso river railroad steel bridge
2020
Abstract The degradation state of railroad steel bridges is one of the most important and difficult aspects to be interpreted. The use of steel bridges started from 1900, and they are still in service today as railroad bridges. The case study examined was that of a bridge railroad steel bridge having a total length of 112 m and constituted by three isostatic, reticular beams having a Pratt type composition. The substructures (two shoulders and two intermediate piles) are in masonry with a reinforced concrete beam in the upper portion. The structure (steel bridge and piers) is in a degraded state. To determine the degradation level, non-destructive and partially destructive tests were carrie…
Novel algorithms for 3D surface point cloud boundary detection and edge reconstruction
2019
Abstract Tessellated surfaces generated from point clouds typically show inaccurate and jagged boundaries. This can lead to tolerance errors and problems such as machine judder if the model is used for ongoing manufacturing applications. This paper introduces a novel boundary point detection algorithm and spatial FFT-based filtering approach, which together allow for direct generation of low noise tessellated surfaces from point cloud data, which are not based on pre-defined threshold values. Existing detection techniques are optimized to detect points belonging to sharp edges and creases. The new algorithm is targeted at the detection of boundary points and it is able to do this better tha…
On the semi-automatic retrieval of biophysical parameters based on spectral index optimization
2014
Abstract: Regression models based on spectral indices are typically empirical formulae enabling the mapping of biophysical parameters derived from Earth Observation (EO) data. Due to its empirical nature, it remains nevertheless uncertain to what extent a selected regression model is the most appropriate one, until all band combinations and curve fitting functions are assessed. This paper describes the application of a Spectral Index (SI) assessment toolbox in the Automated Radiative Transfer Models Operator (ARTMO) package. ARTMO enables semi-automatic retrieval and mapping of biophysical parameters from optical remote sensing observations. The SI toolbox facilitates the assessment of biop…
Supporting public decision process in buildings energy retrofitting operations: the application of a Multiple Criteria Decision Aiding model to a cas…
2020
Abstract The challenge of promoting sustainable cities and reaching the objectives developed by the European Green Deal includes the renovation of the building sector, as it is responsible for 40% of energy consumption in Europe. Regional or local public administrations have to allocate their financial resources for improving the energy performances of their building stock and to face a multidimensional problem, where different aspects – such as energy efficiency, financial-economic feasibility and environmental protection – have to be harmonized. The present study proposes a Multiple Criteria Decision Aiding model, which includes the ELECTRE TRI-nC method, for supporting the public decisio…
Validation and update of the thoracic surgery scoring system (Thoracoscore) risk model.
2020
Abstract OBJECTIVES The performance of prediction models tends to deteriorate over time. The purpose of this study was to update the Thoracoscore risk prediction model with recent data from the Epithor nationwide thoracic surgery database. METHODS From January 2016 to December 2017, a total of 56 279 patients were operated on for mediastinal, pleural, chest wall or lung disease. We used 3 recommended methods to update the Thoracoscore prediction model and then proceeded to develop a new risk model. Thirty-day hospital mortality included patients who died within the first 30 days of the operation and those who died later during the same hospital stay. RESULTS We compared the baseline patient…
Singularities of rational Bézier curves
2001
We prove that if an nth degree rational Bezier curve has a singular point, then it belongs to the two (n − 1)th degree rational Bezier curves defined in the (n − 1)th step of the de Casteljau algorithm. Moreover, both curves are tangent at the singular point. A procedure to construct Bezier curves with singularities of any order is given. 2001 Elsevier Science B.V. All rights reserved.
Irreducible induction and nilpotent subgroups in finite groups
2019
Suppose that $G$ is a finite group and $H$ is a nilpotent subgroup of $G$. If a character of $H$ induces an irreducible character of $G$, then the generalized Fitting subgroup of $G$ is nilpotent.
A Property on Singularities of NURBS Curves
2002
We prove that if a.n open Non Uniform Rational B-Spline curve of order k has a singular point, then it belongs to both curves of order k - 1 defined in the k - 2 step of the de Boor algorithm. Moreover, both curves are tangent at the singular point.
Glow Rate Technique for Spectroscopy of Complex Thermostimulated Relaxation Processes
1996
The glow rate technique (GRT) developed for the analysis of complex trap spectra, is the extension of the known heating rate method to the full glow curve. It is shown that using two glow curves measured at different heating rate constants, a special mean activation energy of simultaneously emptied traps can be obtained as a function of temperature or emitted light sum to a good approximation. Expressions have been derived for the calculation of the mean activation energy function from data measured using a linear, logarithmic or a hyperbolic heating mode. Theoretical expressions for the mean activation energy function have been obtained and discussed for arbitrary trap distribution functio…
Quantitative X-ray diffraction phase analysis of airborne particulate collected by a cascade impactor sampler using the Rietveld full-pattern fitting…
1997
Samples of airborne particulate were collected at the “El Ingenio” site in Castellón (Spain) using a cascade impactor sampler. Quantitative analysis of present phases in the aerosol was performed using the full-pattern fitting Rietveld method. Quantitative information was obtained from refined individual scale factors and unit-cell volumes, obtained with a Rietveld refinement program. Quartz, calcite, and gypsum were encountered as major phases, and their size distribution and concentration in the atmosphere were calculated.