Search results for "Parametric model"
showing 10 items of 63 documents
Parametric Models for Predicting the Performance of Wind Turbines
2020
Abstract Performances of eight parametric power curve models for wind turbines, which can be used for the planning and management of wind energy projects, are compared in this study. Initially, the manufacturer’s power curves of four wind turbines are compared with their field performances. Then, the parametric models are developed for these turbines which are tested with their site performances. Out of the models, WERA showed the best performance in case of all the turbines. Finally, a method for using WERA in extrapolating the performance of turbines with limited test data is demonstrated with the case of a 1 kW turbine.
Analysis of hybrid vehicle transmissions with any number of modes and planetary gearing: kinematics, power flows, mechanical power losses
2021
Abstract This paper is focused on upgrading a unified parametric model, available in the literature, that can perform both the analysis and the design of Power-Split Continuously Variable Transmissions (PS-CVTs), which are particularly promising to deploy in the hybrid electric powertrain. In particular, this work is focused on the analysis of PS-CVTs and proposes a new matrix approach for identifying the basic functional parameters underlying the model from the constructive layout of the transmission. This new method does not rely on a case-specific formulation, thus befits any power-split transmission, regardless of the number of planetary and ordinary gear sets and their constructive arr…
Generative Design for Additively Manufactured Textiles in Orthopaedic Applications
2021
AbstractThe aim of this work is to implement a new process for the design and production of orthopaedic devices to realize entirely by Additive Manufacturing (AM). In particular, a generative algorithm for parametric modelling of flexible structures to use in orthopaedic devices has been developed. The developed modelling algorithm has been applied to a case study based on the design and production of a customized elbow orthosis made by Selective Laser Sintering. The results obtained have demonstrated that the developed algorithm overcomes many drawbacks typical of traditional CAD modelling approaches. FEM simulations have been also performed to validate the design of the orthosis. The new …
Additively manufactured textiles and parametric modelling by generative algorithms in orthopaedic applications
2020
Purpose The purpose of this paper is to implement a new process aimed at the design and production of orthopaedic devices fully manufacturable by additive manufacturing (AM). In this context, the use of generative algorithms for parametric modelling of additively manufactured textiles (AMTs) also has been investigated, and new modelling solutions have been proposed. Design/methodology/approach A new method for the design of customised elbow orthoses has been implemented. In particular, to better customise the elbow orthosis, a generative algorithm for parametric modelling and creation of a flexible structure, typical of an AMT, has been developed. Findings To test the developed modelling a…
Slope units-based flow susceptibility model: using validation tests to select controlling factors
2011
A susceptibility map for an area, which is representative in terms of both geologic setting and slope instability phenomena of large sectors of the Sicilian Apennines, was produced using slope units and a multiparametric univariate model. The study area, extending for approximately 90 km2, was partitioned into 774 slope units, whose expected landslide occurrence was estimated by averaging seven susceptibility values, determined for the selected controlling factors: lithology, mean slope gradient, stream power index at the foot, mean topographic wetness index and profile curvature, slope unit length, and altitude range. Each of the recognized 490 landslides was represented by its centroid po…
Analysis of broadband surface BRDFs derived from TOA SW CERES measurements for surfaces classified by the IGBP land cover
2012
Most studies on the reflectance properties of the Earth's surface are addressed estimating the bidirectional reflectance distribution function (BRDF) of high spatial resolution and high spectral resolution satellite measurements. This article assesses the development of broadband (BB) BRDFs from radiances corresponding to large footprints classified according to the International Geosphere-Biosphere Programme (IGBP) land-cover classification. Top-of-atmosphere (TOA) shortwave (SW) CERES (Clouds and the Earth's Radiant Energy System) measurements are employed to invert the bidirectional reflectance factor (BRF) Rahman–Pinty–Verstraete (RPV) model for regions identified with the same IGBP typ…
Assessment of Granger causality by nonlinear model identification: application to short-term cardiovascular variability.
2007
A method for assessing Granger causal relationships in bivariate time series, based on nonlinear autoregressive (NAR) and nonlinear autoregressive exogenous (NARX) models is presented. The method evaluates bilateral interactions between two time series by quantifying the predictability improvement (PI) of the output time series when the dynamics associated with the input time series are included, i.e., moving from NAR to NARX prediction. The NARX model identification was performed by the optimal parameter search (OPS) algorithm, and its results were compared to the least-squares method to determine the most appropriate method to be used for experimental data. The statistical significance of…
Statistical Learning Algorithms to Forecast the Equity Risk Premium in the European Union
2018
With the explosion of “Big Data”, the application of statistical learning models has become popular in multiple scientific areas as well as in marketing, finance or other business disciplines. Nonetheless, there is not yet an abundant literature that covers the application of these learning algorithms to forecast the equity risk premium. In this paper we investigate whether Classification and Regression Trees (CART) algorithms and several ensemble methods, such as bagging, random forests and boosting, improve traditional parametric models to forecast the equity risk premium. In particular, we work with European Monetary Union data for a period that spans from the EMU foundation at the begin…
Comparison of Canopy Emissivity Parametric Models With TES Emissivity Measurements
2018
Canopy temperature is a key factor in many studies, such as evapotranspiration and heat fluxes estimation. To retrieve it accurately, it is needed a precise characterization of the emissivity in the thermal infrared spectral range. Several parametric models are proposed to retrieved effective emissivity at different observation angles, from the previous knowledge of the vegetation and soil emissivities. The present work compares some of these models with emissivity measurements obtained with Temperature-Emissivity Separation (TES) method. For that, FR97, Mod3 and Rmod3 parametric models have been compared with radiometric measurements. Emissivity measurements were done for 7 different obser…
Shear Effects in Elastic Nanobeams
2020
Small-scale, shear deformable nanobeams, subjected to quasi-static loads, are analyzed by a nonlocal (integral) elasticity model with the main goal to evaluate the influence of shear deformation on size effects. To this aim a warping parametric model is considered in order to obtain a continuous family of shear deformable beam models which span from the Euler-Bernoulli to the Thimoshenko beam model, passing from the Reddy model. The strain difference based nonlocal elasticity theory is applied under the hypotheses of small displacements and isotropic material. The results, obtained by analysing a cantilever nonlocal nanobeam, indicate that shear deformation has a considerable influence upon…