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See detailError bounds on the non-normal approximation of Hermite power variations of fractional Brownian motion
Breton, Jean-Christophe; Nourdin, Ivan UL

in Electronic Communications in Probability (2008), 13

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See detailError controlled adaptive multiscale method for fracture in polycrystalline materials
Akbari Rahimabadi, Ahmad; Kerfriden, Pierre; Bordas, Stéphane UL

Report (2014)

A lack of separation of scales is the major hurdle hampering predictive and computationally tractable simulations of fracture over multiple scales. In this thesis an adaptive multiscale method is ... [more ▼]

A lack of separation of scales is the major hurdle hampering predictive and computationally tractable simulations of fracture over multiple scales. In this thesis an adaptive multiscale method is presented in an attempt to address this challenge. This method is set in the context of FE2 Feyel and Chaboche [2000] for which computational homogenisation breaks down upon loss of material stability (softening). The lack of scale separation due to the coalescence of microscopic cracks in a certain zone is tackled by a full discretisation of the microstructure in this zone. Polycrystalline materials are considered with cohesive cracks along the grain boundaries as a model problem. Adaptive mesh re nement of the coarse region and adaptive initiation and growth of fully resolved regions are performed based on discretisation error and homogenisation error criteria, respectively. In order to follow sharp snap-backs in load-displacement paths, a local arc-length technique is developed for the adaptive multiscale method. The results are validated against direct numerical simulation [less ▲]

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See detailError Controlled Adaptive Multiscale Method For Fracture Modelling in Polycrystalline materials
Akbari, Ahmad; Kerfriden, ierre; Bordas, Stéphane UL

in Philosophical Magazine (2015)

In this paper an adaptive multiscale method is presented in an attempt to address the lack of separation of scales in simulation of fracture. This method is set in the context of FE2 [20] for which ... [more ▼]

In this paper an adaptive multiscale method is presented in an attempt to address the lack of separation of scales in simulation of fracture. This method is set in the context of FE2 [20] for which computational homogenisation breaks down upon loss of material stability (softening). The lack of scale separation due to the coalescence of microscopic cracks in a certain zone is tackled by a full discretisation of the microstructure in this zone. Polycrystalline materials are considered with cohesive cracks along the grain boundaries as a model problem. Adaptive mesh refinement of the coarse region and adaptive initiation and growth of fully resolved regions are performed based on discretisation error and homogenisation error criteria, respectively. In order to follow sharp snap-backs in load-displacement paths, a local arc-length technique is developed for the adaptive multiscale method. The results are validated against direct numerical simulation. [less ▲]

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See detailError detection and management in CAN XR
Cena, Gianluca; Cibrario Bertolotti, Ivan; Hu, Tingting UL et al

in 2018 14th IEEE International Workshop on Factory Communication Systems (WFCS) (2018)

Nowadays, Controller Area Network is still the most popular solution for in-vehicle communications in automotive scenarios. Recently, the CAN with eXtensible in-frame Replyproposal has been introduced ... [more ▼]

Nowadays, Controller Area Network is still the most popular solution for in-vehicle communications in automotive scenarios. Recently, the CAN with eXtensible in-frame Replyproposal has been introduced, which permits several nodes to write at the same time on the bus in the data field of legacy CAN frames. This enables several new interesting communication services, including distributed key generation and highly-efficient data exchanges according to the combined message approach. Unfortunately, having several concurrent devices acting as transmitters for the same message impairs the ability of the protocol to detect global errors, hence worsening its robustness against electromagnetic disturbance. In this paper, this problem is analyzed in detail and some solutions are proposed, which make CAN XR as robust as the standard CAN protocol. [less ▲]

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See detailError estimation and bounding in energy norm based on a displacement recovery technique
Nadal, E.; González-Estrada, O. A.; Ródenas, J. J. et al

in Eberhardsteiner, Josef; Böhm, Helmut; Rammerstorfer, F G (Eds.) 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) (2012)

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See detailError estimation and error bounding in energy norm based on a displacement recovery technique
Nadal, E.; González-Estrada, O. A.; Ródenas, J. J. et al

in ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers (2012)

Traditionally, recovery based error estimators in linear elasticity have considered the evaluation of an enhanced stress field obtained from the raw Finite Element (FE) stress solution. Instead of that ... [more ▼]

Traditionally, recovery based error estimators in linear elasticity have considered the evaluation of an enhanced stress field obtained from the raw Finite Element (FE) stress solution. Instead of that, one can also obtain a recovered displacement field from the FE displacements. Herein, we describe a superconvergent patch recovery of the displacement field which considers the local fulfilment of boundary and internal equilibrium equations, Dirichlet constraints and, for singular problems, the splitting of the displacement and stress fields into singular and smooth parts. Numerical tests using problems with known analytical solution have been carried out to validate the proposed technique for error estimation and error bounding in energy norm and quantities of interest. [less ▲]

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See detailError estimation and error bounding in quantities of interest based on equilibrated recovered displacement fields
Nadal, E.; González-Estrada, O. A.; Ródenas, J. J. et al

in ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers (2012)

Over the last ten years there has been an increase on the use of goal-oriented error estimates aimed to quantify the local error on a (non)linear quantity of interest (QoI) that might result relevant for ... [more ▼]

Over the last ten years there has been an increase on the use of goal-oriented error estimates aimed to quantify the local error on a (non)linear quantity of interest (QoI) that might result relevant for design purposes. Residual-based error estimators have been used recursively to obtain upper and lower bounds of the error in quantities of interest for finite element approximations. In this paper, we present a recovery technique for 2D linear elasticity problems, based on the superconvergent patch recovery (SPR), which provides recovered displacement and stress fields that are then utilised to evaluate practical upper and lower error bounds in QoI. [less ▲]

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See detailError estimation and space-time adaptivity for the isogeometric analysis of transient structural dynamics
Yu, Peng; Claus, Susanne; Bordas, Stéphane UL et al

Scientific Conference (2016, April 01)

This paper presents a new adaptive scheme for the error-controlled simulation of transient dynamics problem. We rely on spline bases for the higher-order spatial description of our kinematic fields. Local ... [more ▼]

This paper presents a new adaptive scheme for the error-controlled simulation of transient dynamics problem. We rely on spline bases for the higher-order spatial description of our kinematic fields. Local adaptivity is performed by employing a hierarchical T-mesh technology, in combination with geometry independent field approximation. The Newmark algorithm is chosen to solve the semidiscrete equation of motion. We will present some simple local error estimates to drive the adaptivity, and show how we can ensure that the mechanical energy of conservative systems is preserved during the refinement process. [less ▲]

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See detailError estimation in homogenisation
Alves Paladim, Daniel; Kerfriden, Pierre; Moitinho de Almeida, José et al

Presentation (2015, January 30)

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See detailError estimation in quantities of interest for XFEM using recovery techniques
González-Estrada, O. A.; Nadal, E.; Ródenas, J. J. et al

in Yang, Z J (Ed.) 20th UK National Conference of the Association for Computational Mechanics in Engineering (ACME) (2012)

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See detailError estimation of recovered solutions in FE analysis. Higher order h-adaptive refinement strategies
Ródenas, J. J.; Nadal, E.; González-Estrada, O. A. et al

in Pimienta, P M (Ed.) 10th World Congress on Computational Mechanics (WCCM 2012) (2012)

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See detailThe Error Probability of the Fixed-Complexity Sphere Decoder
Jalden, Joakim; Barbero, Luis G.; Ottersten, Björn UL et al

in IEEE Transactions on Signal Processing (2009), 57(7), 2711-2720

Download Citation Email Print Request Permissions Save to Project The fixed-complexity sphere decoder (FSD) has been previously proposed for multiple-input multiple-output (MIMO) detection in order to ... [more ▼]

Download Citation Email Print Request Permissions Save to Project The fixed-complexity sphere decoder (FSD) has been previously proposed for multiple-input multiple-output (MIMO) detection in order to overcome the two main drawbacks of the sphere decoder (SD), namely its variable complexity and its sequential structure. Although the FSD has shown remarkable quasi-maximum-likelihood (ML) performance and has resulted in a highly optimized real-time implementation, no analytical study of its performance existed for an arbitrary MIMO system. Herein, the error probability of the FSD is analyzed, proving that it achieves the same diversity as the maximum-likelihood detector (MLD) independent of the constellation used. In addition, it can also asymptotically yield ML performance in the high-signal-to-noise ratio (SNR) regime. Those two results, together with its fixed complexity, make the FSD a very promising algorithm for uncoded MIMO detection. [less ▲]

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See detailError-controlled adaptive extended finite element method for 3D linear elastic crack propagation
Jin, Y.; González-Estrada, O. A.; Pierard, O. et al

in Computer Methods in Applied Mechanics & Engineering (2017), 318

We present a simple error estimation and mesh adaptation approach for 3D linear elastic crack propagation simulations using the eXtended Finite Element Method (X-FEM). A global extended recovery technique ... [more ▼]

We present a simple error estimation and mesh adaptation approach for 3D linear elastic crack propagation simulations using the eXtended Finite Element Method (X-FEM). A global extended recovery technique (Duflot and Bordas, 2008) is used to quantify the interpolation error. Based on this error distribution, four strategies relying on two different mesh optimality criteria are compared. The first aims at homogenizing the error distribution. The second minimizes the total number of elements given a target global error level. We study the behaviour of these criteria in the context of cracks treated by an X-FE approach. In particular, we investigate the convergence rates at the element-level depending its enrichment type. We conclude on the most suitable refinement criterion and propose and verify a strategy for mesh adaptation on 3D damage tolerance assessment problems. [less ▲]

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See detailError-controlled computational fracture mechanics
Bordas, Stéphane UL

Scientific Conference (2017, July 12)

Detailed reference viewed: 350 (32 UL)
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See detailErscheinungsbild und Erklärungsmuster der asiatischen Wirtschaftskrise
Klump, Rainer UL

in Schubert, R. (Ed.) Ursachen und Therapien regionaler Entwicklungskrisen – Das Beispiel der Asienkrise (2000)

Detailed reference viewed: 26 (0 UL)
See detailDer erste nationale Bildungsbericht für Luxemburg - Ziele und Themen
Lenz, Thomas UL; Bertemes, Jos

in Université du Luxembourg; MENJE (Eds.) Bildungsbericht Luxemburg 2015. Band 2: Analysen und Befunde (2015)

Detailed reference viewed: 101 (23 UL)
See detailDas erste Spital in Luxemburg. Eine unerforschte Quelle zum Wirken Walrams von Monschau-Limburg und zur Geschichte der Stadt Luxemburg
Margue, Michel UL; Pauly, Michel UL

in Hemecht : Zeitschrift für Luxemburger Geschichte = Revue d'Histoire Luxembourgeoise (1995), 47(1), 15-42

Detailed reference viewed: 48 (1 UL)
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See detailDie erste Transformation der europäischen Landwirtschaft: Von der naturbezogenen zur industriellen Produktion
Nienaber, Birte UL

in Gebhardt, Hans; Glaser, Rüdiger; Lentz, Sebastian (Eds.) Europa- eine Geographie (2012)

The book chapter explains the main developments of agriculture in Europe since the 18th centrury.

Detailed reference viewed: 42 (1 UL)