Search results for "angles"

showing 10 items of 50 documents

Detection of damage in civil engineering structures by PCA on enviromental vibration data

2018

The dynamic behavior of civil engineering structures are usually studied by means of ambient vibration observations and their performance is analyzed by Peak Picking and/or Operational Modal Analysis methods. This paper reports the first results of a statistical multivariate approach, specifically Principal Component Analysis, to detect a suspected structural damage on a sicilian highway bridge. Furthermore, the damage simulated in a simple structural model made it possible to understand the characteristics of the method consisting in comparing the observed data on an undamaged structure with those coming from a damaged one.

Principal component analysis damage detection subspace angles Operational modal analysis Fast Fourier Transform Peak Picking
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Existence of a traveling wave solution in a free interface problem with fractional order kinetics

2021

Abstract In this paper we consider a system of two reaction-diffusion equations that models diffusional-thermal combustion with stepwise ignition-temperature kinetics and fractional reaction order 0 α 1 . We turn the free interface problem into a scalar free boundary problem coupled with an integral equation. The main intermediary step is to reduce the scalar problem to the study of a non-Lipschitz vector field in dimension 2. The latter is treated by qualitative topological methods based on the Poincare-Bendixson Theorem. The phase portrait is determined and the existence of a stable manifold at the origin is proved. A significant result is that the settling time to reach the origin is fin…

Settling timeScalar (mathematics)01 natural sciencesPoincare-Bendixson TheoremTraveling wave solutionsMathematics - Analysis of PDEsDimension (vector space)Free boundary problemFOS: Mathematics[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]Trapping triangles0101 mathematicsMathematicsPhase portraitApplied Mathematics010102 general mathematicsMathematical analysisIntegral equationStable manifoldDiffusional-thermal combustionFree interface problems010101 applied mathematicsVector fieldFractional order kineticsAnalysisAnalysis of PDEs (math.AP)
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Flexural behaviour of RC columns strengthened with steel angles and strips

2011

Settore ICAR/09 - Tecnica Delle CostruzioniRC columns strengthening confinement steel angles
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Modelling steel jacketed RC columns: Remarks by experimental-numerical comparisons

2015

The recent large use of nonlinear seismic assessment techniques requires the definition of highly reliable computational models. The retrofitting or strengthening of RC columns by steel angles and battens is a commonly adopted technique, used to improve strength and deformation capacity of existing RC buildings. In the case of steel angles not directly loaded, the numerical definition of the cross-section model has to be handled carefully since it is affected by more uncertainties. The vertical load carried by the angles is a function of the lateral confinement pressure, the cohesion and the friction coefficient between the materials, parameters which are not always easy to predict. The pap…

Settore ICAR/09 - Tecnica Delle CostruzionicohesionconfinementOpenseesfrictionnumerical modellingOpensees confinement cohesion friction numerical modelling steel anglesCohesion friction numerical modelling steel angles opensees confinementsteel angles
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Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
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Sign-preserving solutions for a class of asymptotically linear systems of second-order ordinary differential equations

2022

We study multiplicity of solutions to an asymptotically linear Dirichlet problem associated with a planar system of second order ordinary differential equations. The existence of two sign-preserving component-wise solutions is guaranteed when the Morse indexes of the linearizations at zero and at infinity do not coincide, and one of the asymptotic problems has zero-index. The proof is developed in the framework of topological and shooting methods and it is based on a detailed analysis and characterization of the phase angles in a two-dimensional setting.

Settore MAT/05 - Analisi MatematicaApplied MathematicsAnalysisAsymptotically Linear Planar Systems Sign-preserving Solutions Morse Index Phase Angles
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L’aprenentatge de la pronúncia anglesa mitjançant REO: El cas de Voki

2018

Al llarg dels anys, l’anglès s’ha situat com una vertadera llengua global a la nostra societat. Això ha donat pas a l’aplicació d’un nombre de mètodes i enfocaments pel que fa a l’àrea d’ensenyament i aprenentatge de l’anglès com a llengua estrangera o segona llengua, on tant la integració de les Tecnologies de la Informació i la Comunicació (TIC) com dels Recursos Educatius Oberts (REO) és primordial. Tenint això en compte, aquest estudi té dos objectius. D’una banda, es pretén investigar fins a quin punt els estudiants universitaris matriculats a l’assignatura de Pronunciació i Comprensió de l’ Anglès Oral són capaços de millorar la pronunciació mitjançant l’eina en línia anomenada Voki. …

TICLinguistics and Languagelcsh:Comparative grammarmedia_common.quotation_subjectAnglèsEnglish as a Foreign/Second Language (EFL/ESL)Artlcsh:P325-325.5Llengua segona AdquisicióLanguage and LinguisticsInnovacions tecnològiquesAnglès com a llengua estrangera/segona llenguaVoki.Teaching englishICTsICTSPronunciació anglesaVokilcsh:P201-299Humanitiesmedia_commonEnglish pronunciationlcsh:SemanticsSintagma
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Canopy Architecture Appraisal by Fractal Dimension of 'Flordastar' Peach Trees Grafted onto Different Rootstocks

2007

The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour, by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara, Barrier, GF677 and MrS 2/5 rootstocks. On digital pictures of leafless, dormant peach tree…

The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara Barrier GF677 and MrS 2/5 rootstocks. On digital pictures of leafless dormant peach trees the tree skeleton was manually depicted by an image analysis software to measure total length and angles of insertion of branches. Bitmaps of the skeleton were then subjected to a specific software (FDCALC) able to calculate D by the "box counting" method. To account for the error introduced by analyzing a three dimensional structure with its 2D projection measurements were done on two images per tree taken from two different viewing angles. Results are shown in relation to tree vigour of the scion/stock combination. Fractal dimension was related to the vigour ranking of the graft combinations tested. In particular vigorous scion/stock combinations showed the highest D.HorticultureCanopy architectureHorticultureRootstockFractal dimensionMathematics
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Els triangles amorosos i l'amor cast. Alguns paral·lelismes entre la novel·la grega antiga i ¨Tirant lo Blanc¨

2018

Malgrat la distància temporal, cultural i lingüística que separa el Tirant lo Blanch i la novel·la grega antiga, es poden establir paral·lelismes evidents en personatges, escenes i motius, pel que fa al tractament de l?amor. En el present article ens centrem en l?enamorament de la parella de protagonistes de la novel·la de Joanot Martorell i de la novel·la d?Aquil·les Taci, Leucipe i Clitofont  (s. II dC), i en algunes fites pel que fa al progrés de la seva relació amorosa. A continuació, analitzem els personatges de l?emperadriu i la Viuda Reposada, amb el mirall de les dones adúlteres de les novel·les Leucipe i Clitofont i Etiòpiques, com a protagonistes dels respectius triangles amorosos…

UNESCO::CIENCIAS DE LAS ARTES Y LAS LETRAS:CIENCIAS DE LAS ARTES Y LAS LETRAS [UNESCO]Triangles amorosos amor cast Carmesina Tirant Viuda Reposada Leucipe i Clitofont Etiòpiques Àrsace Demeneta Teàgenes Hipòlit Clitofont Leucipe
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Poetes catalanes i poetes angleses als anys d'entreguerres. A propòsit d'una antologia ja feta i una per fer

2015

L’objectiu principal d’aquest article és estudiar la poesia femenina catalana del període d’entreguerres aplicant dues metodologies: d’una banda, la literatura comparada, tot relacionant les escriptores catalanes amb les escriptores angleses del mateix període; i de l’altra banda, la crítica feminista, utilitzant alguns dels seus paradigmes. L’altre gran objectiu és reivindicar la qualitat d’algunes d’aquestes autores, com ara Roser Matheu, M. Teresa Vernet, Simona Gay, Maria Perpinyà i Cèlia Viñas, i també posar de manifest la importància que haurien de tenir en la història literària catalana contemporània.

UNESCO::CIENCIAS DE LAS ARTES Y LAS LETRASpoesia femenina; poesia catalana; poesia anglesa; període d’entreguerres; crítica literàriaPoesia catalanaCrítica literàriaLingüísticaFilologías:CIENCIAS DE LAS ARTES Y LAS LETRAS [UNESCO]Poesia anglesaPoesia femeninaPeríode d’entreguerres
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