Search results for "Basis"
showing 10 items of 760 documents
The Bernstein Basis and its applications in solving geometric constraint systems
2012
International audience; This article reviews the properties of Tensorial Bernstein Basis (TBB) and its usage, with interval analysis, for solving systems of nonlinear, univariate or multivariate equations resulting from geometric constraints. TBB are routinely used in computerized geometry for geometric modelling in CAD-CAM, or in computer graphics. They provide sharp enclosures of polynomials and their derivatives. They are used to reduce domains while preserving roots of polynomial systems, to prove that domains do not contain roots, and to make existence and uniqueness tests. They are compatible with standard preconditioning methods and fit linear program- ming techniques. However, curre…
Studi greci e latini nell?antica Università di Altamura (1748-1821)
2019
The article tries to highlight, despite the scarse of available documentation, the Greek and Latin studies (language and texts) in the ancient Apulian University in Altamura (1748-1821). Furthermore, on the basis of unpublished archival materials (school registers and student workbooks) it is possible to shed light on the ancient authors explained at school, the teaching methods, and the study practices.
Identification of a specific type of PD from acoustic emission frequency spectra
2001
The paper presents an attempt to apply spectral analysis tools in processing acoustic emission (AE) pulses generated by partial discharge (FD). The experimental part of the paper describes spark gaps generating four types of PD and specifies parameters of measured acoustic signals and recalls the system used for measurement and analysis of the frequency spectra. Also, a spectral analysis procedure is presented, and frequency-domain descriptors characterizing AE pulses are defined. The results of the analysis are given both as time plots and amplitude and energy density spectra, related to values of the associated descriptors. The spectral analysis results cover AE pulses generated in system…
The Anabasis of Patrick: Travelling an allegorical narrative map of illness and disability
2018
Abstract Objectives This paper examines the stories of Patrick, a man living with cancer and a spinal cord injury. Design An intrinsic case study was used to address Patrick's experiences. The design of the study is underpinned by narrative dialogism. Method Photo-elicitation interviews were conducted. Visual and verbal data were analysed using a dialogical narrative analysis. Results Patrick aligned his experiences with a story titled Anabasis to organize and express them. Although Anabasis is not a story about illness, it provides Patrick with an allegorical narrative map of how to live with disability and survive illness. Within ‘The Anabasis of Patrick’, the analysis identified three st…
High‐nuclearity mixed‐valence magnetic clusters : A general solution of the double exchange problem
1996
We report here a general solution of the double‐exchange problem in the high‐nuclearity mixed valence systems containing arbitrary number P of the electrons delocalized over the network of N (P<N) localized spins. The developed approach is based on the successive (chainlike) spin‐coupling scheme and takes full advantage from the quantum angular momentum theory. In the framework of this approach the closed‐form analytical expressions are deduced for the matrix elements of the double exchange interaction, two‐electron transfer, and three‐center interaction that can be referred to as the potential exchange transfer. For the arbitrary nuclearity mixed‐valence systems the matrix elements of all …
Internal fe approximation of spaces of divergence-free functions in three-dimensional domains
1986
SUMMARY The space of divergence-free vector functions with vanishing normal flux on the boundary is approximated by subspaces of finite elements having the same property. An easy way of generating basis functions in these subspaces is shown.
Calculation of the relative basicities of methylamines in solution
1990
Abstract The relative basicities in solution of the methylamines have been calculated using the model of Miertus, Scrocco and Tomasi to describe the solvent effect. The surface of the cavity is defined with the GEPOL method. The ab initio calculations have been performed using a 4-31G basis set. The relative order is reproduced using a combination of the gas-phase proton affinities obtained with quantum-mechanical methods by Eades, Weil, Dixon and Douglass and the solvation values obtained by us. The results seem to point out that the irregular order is not due to solvent but to basis-set effects.
Robust adaptive neural backstepping control for a class of nonlinear systems with dynamic uncertainties
2014
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/658671 Open Access This paper is concerned with adaptive neural control of nonlinear strict-feedback systems with nonlinear uncertainties, unmodeled dynamics, and dynamic disturbances. To overcome the difficulty from the unmodeled dynamics, a dynamic signal is introduced. Radical basis function (RBF) neural networks are employed to model the packaged unknown nonlinearities, and then an adaptive neural control approach is developed by using backstepping technique. The proposed controller guarantees semiglobal boundedness of all the signals in the…
Modelling and Analysis of Nonstationary Vehicle-to-Infrastructure Channels with Time-Variant Angles of Arrival
2018
In mobile radio channel modelling, it is generally assumed that the angles of arrival (AOAs) are independent of time. This assumption does not in general agree with real-world channels in which the AOAs vary with the position of a moving receiver. In this paper, we first present a mathematical model for the time-variant AOAs. This model serves as the basis for the development of two nonstationary multipath fading channels models for vehicle-to-infrastructure communications. The statistical properties of both channel models are analysed with emphasis on the time-dependent autocorrelation function (ACF), time-dependent mean Doppler shift, time-dependent Doppler spread, and the Wigner-Ville sp…
Neural Networks as Soft Sensors: a Comparison in a Real World Application.
2006
Physical atmosphere parameters, as temperature or humidity, can be indirectly estimated on the surface of a monument by means of soft sensors based on neural networks, if an ambient air monitoring station works in the neighborhood of the monument itself. Since the soft sensors work as virtual instruments, the accuracy of such measurements has to be analyzed and validated from statistical and metrological points of view. The paper compares different typologies of neural networks, which can be used as soft sensors in a complex real world application: a non invasive monitoring of the conservation state of old monuments. In this context, several designed connessionistic systems, based on radial…