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See detailMultiscale Quasicontinuum Methods for Dissipative Truss Models and Beam Networks
Beex, Lars UL; Peerlings, Ron; Geers, Marc et al

Presentation (2014, November 05)

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See detailMultiscale quasicontinuum methods for fibrous materials
Beex, Lars UL; Peerlings, Ron; Geers, Marc et al

Scientific Conference (2014, July)

The QC method was originally proposed for (conservative) atomistic lattice models and is based on energy-minimization. Lattice models for fibrous materials however, are often non-conservative and energy ... [more ▼]

The QC method was originally proposed for (conservative) atomistic lattice models and is based on energy-minimization. Lattice models for fibrous materials however, are often non-conservative and energy-based QC methods can thus not straightforwardly be used. Examples presented here are a lattice model proposed for woven fabrics and a lattice model to describe interfiber bond failure and subsequent frictional fiber slidings. A QC framework is proposed that is based on the virtual-power statement of a non-conservative lattice model. Using the virtual-power statement, dissipative mechanisms can be included in the QC framework while the same summation rules suffice. Its validity is shown for a lattice model with elastoplastic trusses. The virtual-power-based QC method is also adopted to deal with the lattice model for bond failure and subsequent fiber sliding presented. In contrast to elastoplastic interactions that are intrinsically local dissipative mechanisms, bond failure and subsequent fiber sliding entail nonlocal dissipative mechanisms. Therefore, the virtual-power-based QC method is also equipped with a mixed formulation in which not only the displacements are interpolated, but also the internal variables associated with dissipation. [less ▲]

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See detailMultiscale simulations of fracture, mesh burden reduction with applications to surgical simulation
Bordas, Stéphane UL

Presentation (2014, April 10)

ABSTRACT We present recent results aiming at affording faster and error-controlled simulations of multi scale phenomena including fracture of heterogeneous materials and cutting of biological tissue. In a ... [more ▼]

ABSTRACT We present recent results aiming at affording faster and error-controlled simulations of multi scale phenomena including fracture of heterogeneous materials and cutting of biological tissue. In a second part, we describe methodologies to isolate the user from the burden of mesh generation and regeneration as moving boundaries evolve. Results include advances in implicit boundary finite elements, (enriched) isogeometric extended boundary elements/finite element methods for multi-crack propagation and an asynchronous GPU/CPU method for contact and cutting of heterogeneous materials in real-time with applications to surgical simulation. ABOUT THE PRESENTER In 1999, Stéphane Bordas joined a joint graduate programme of the French Institute of Technology (Ecole Spéciale des Travaux Publics) and the American Northwestern University. In 2003, he graduated in Theoretical and Applied Mechanics with a PhD from Northwestern University. Between 2003 and 2006, he was at the Laboratory of Structural and Continuum Mechanics at the Swiss Federal Institute of Technology in Lausanne, Switzerland. In 2006, he became permanent lecturer at Glasgow University’s Civil Engineering Department. Stéphane joined the Computational Mechanics team at Cardiff University in September 2009, as a Professor in Computational Mechanics and directed the institute of Mechanics and Advanced Materials from October 2010 to November 2013. He is the Editor of the book series “Advances in Applied Mechanics” since July 2013. In November 2013, he joined the University of Luxembourg as a Professor in Computational Mechanics. The main axes of his research team include (1) free boundary problems and problems involving complex geometries, in particular moving boundaries and (2) ‘a posteriori’ discretisation and model error control, rationalisation of the computational expense. Stéphane’s keen interest is to actively participate in innovation, technological transfer as well as software tool generation. This has been done through a number of joint ventures with various industrial partners (Bosch GmbH, Cenaero, inuTech GmbH, Siemens-LMS, Soitec SA) and the release of open-source software. In 2012, Stéphane was awarded an ERC Starting Independent Research Grant (RealTcut), to address the need for surgical simulators with a computational mechanics angle with a focus on the multi-scale simulation of cutting of heterogeneous materials in real-time. [less ▲]

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See detailMultiscale-multiphysics approaches for engineering applications
Pozzetti, Gabriele UL; Peters, Bernhard UL

in AIP Conference Proceedings (2017), 1863(1), 180001

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See detailMultiset Collision Attacks on Reduced-Round SNOW 3G and SNOW 3G (+)
Biryukov, Alex UL; Priemuth-Schmid, Deike UL; Zhang, Bin UL

in ACNS 2010 (2010)

The stream cipher SNOW 3G designed in 2006 by ETSI/SA-GE is a base algorithm for the second set of 3GPP confidentiality and integrity algorithms. In this paper we study the resynchronization mechanism of ... [more ▼]

The stream cipher SNOW 3G designed in 2006 by ETSI/SA-GE is a base algorithm for the second set of 3GPP confidentiality and integrity algorithms. In this paper we study the resynchronization mechanism of SNOW 3G and of a similar cipher SNOW 3G ⊕  using multiset collision attacks. For SNOW 3G we show a simple 13-round multiset distinguisher with complexity of 28 steps. We show full key recovery chosen IV resynchronization attacks for up to 18 out of 33 initialization rounds of SNOW3G ⊕  with a complexity of 257 to generate the data and 253 steps of analysis. [less ▲]

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See detailMultiset-Algebraic Cryptanalysis of Reduced Kuznyechik, Khazad, and secret SPNs
Biryukov, Alex UL; Khovratovich, Dmitry UL; Perrin, Léo Paul UL

in IACR Transactions on Symmetric Cryptology (2016), 2016(2), 226-247

We devise the first closed formula for the number of rounds of a blockcipher with secret components so that these components can be revealed using multiset, algebraic-degree, or division-integral ... [more ▼]

We devise the first closed formula for the number of rounds of a blockcipher with secret components so that these components can be revealed using multiset, algebraic-degree, or division-integral properties, which in this case are equivalent. Using the new result, we attack 7 (out of 9) rounds of Kuznyechik, the recent Russian blockcipher standard, thus halving its security margin. With the same technique we attack 6 (out of 8) rounds of Khazad, the legacy 64-bit blockcipher. Finally, we show how to cryptanalyze and find a decomposition of generic SPN construction for which the inner-components are secret. All the attacks are the best to date. [less ▲]

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See detailMultisets in arithmetics
Perucca, Antonella UL

Diverse speeches and writings (n.d.)

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See detailMultiskalenmodellierung für technische Anwendungen
Peters, Bernhard UL

in ECEMP 2015, European Centre for Emerging Materials and Processes (2015)

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See detailMultistability of genetic regulatory networks
Pan, Wei UL; Zhang, Z.; Liu, H.

in International Journal of Systems Science (2010), 41(1), 107-118

Multistability is found to be an important recurring theme in synthesis biology. In this article, the multistability analysis problem is investigated by applying control theory and mathematical tools ... [more ▼]

Multistability is found to be an important recurring theme in synthesis biology. In this article, the multistability analysis problem is investigated by applying control theory and mathematical tools. Both the modelling and analysis issues are discussed. Specifically, the genetic regulatory networks (GRNs) with multistability are modelled as switched systems with interval time-varying delays and parameter uncertainties, where the piecewise-affine models are used to approximate the inherent non-linearities existing in the GRNs. Then, by using a novel Lyapunov functional approach and linear matrix inequality (LMI) techniques, a few delay-dependent criteria for the multistability of such genetic regulatory networks are established in the form of LMIs, which can be readily verified by using standard numerical software. A three-component network and a genetic toggle switch with bistability are employed to illustrate the applicability and usefulness of the developed theoretical results. [less ▲]

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See detailMultistage Downstream Attack Detection in a Cyber Physical System
Qadeer, Rizwan UL; Murguia, Carlos; Ahmed, Chuadhry Mujeeb et al

in 3rd Workshop on the Security of Industrial Control Systems and of Cyber-Physical Systems In Conjunction With ESORICS 2017 (2017, September)

We present a detection scheme for attacks on a Cyber-Physical System (CPS) in which we leverage the connectivity of a multistage process to detect attacks downstream from the point of attack. Our methods ... [more ▼]

We present a detection scheme for attacks on a Cyber-Physical System (CPS) in which we leverage the connectivity of a multistage process to detect attacks downstream from the point of attack. Our methods form a control theoretic approach to CPS security by characterizing a real water treatment facility with a mathematical model; obtaining a residual (error) signal from sensor measurements and sensor measurement estimates; and finally using Cumulative Sum (CUSUM) and Bad-Data detection methods to detect the presence of a sensor attack. In particular, the attacks are designed so that they do not raise alarms on the detectors in the same stage where the attack takes place, requiring detection to take place on a separate part of the system. Proposed scheme is implemented on a real world water treatment facility. Extensive experiments are carried out and results show the significance of the proposed scheme. [less ▲]

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See detailA Multithreading Local Search For Multiobjective Energy-Aware Scheduling In Heterogeneous Computing Systems
Iturriaga, Santiago; Nesmachnow, Sergio; Dorronsoro, Bernabé UL

in European Conference on Modelling and Simulation (ECMS) (2012)

This article introduces an efficient multithreading local search algorithm for solving the multiobjective scheduling problem in heterogeneous computing systems considering the makespan and energy ... [more ▼]

This article introduces an efficient multithreading local search algorithm for solving the multiobjective scheduling problem in heterogeneous computing systems considering the makespan and energy consumption objectives. The proposed method follows a fully multiobjective approach using a Pareto-based dominance search executed in parallel. The experimental analysis demonstrates that the new multithreading algorithm outperforms a set of deterministic heuristics based on Min-Min. The new method is able to achieve significant improvements in both objectives in reduced execution times for a broad set of testbed instances. [less ▲]

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See detailA multitrait-multimethod study of assessment instruments for Complex Problem Solving
Greiff, Samuel UL; Fischer, Andreas; Wüstenberg, Sascha UL et al

in Intelligence (2013), 41

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See detailA multiuser downlink system combining limited feedback and channel correlaton information
Huang, Yongming; Yang, Luxi; Bengtsson, Mats et al

in Communications (ICC), 2010 IEEE International Conference on (2010)

We address the problem of combining limited feedback information with long-term channel statistical information in the design of downlink SDMA schemes. A novel combining method is developed to improve the ... [more ▼]

We address the problem of combining limited feedback information with long-term channel statistical information in the design of downlink SDMA schemes. A novel combining method is developed to improve the quality of channel knowledge at the base station. More specifically, a set of novel feedback parameters is proposed and a related method is developed to estimate a representation of the multiuser channel vectors at the base station. This method utilizes the hybrid information by combining instantaneous channel feedback and long-term channel statistics, and is based on a channel phase codebook designed using the generalized Lloyd algorithm. The estimated channel knowledge at the base station can be used for joint design of multiuser precoding and opportunistic scheduling. The advantage of the proposed scheme over existing CSI quantization based SDMA schemes is further confirmed by computer simulations. [less ▲]

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See detailMultivariate Approach to Creativity: Cognition and Personality
Kirsch, Christiane UL; Houssemand, Claude UL

Scientific Conference (2012, June)

Our study is founded on a multivariate approach to creativity. We analyze cognitive and personality variables in relationship to creative potential. The sample consists of 37 middle aged adults from the ... [more ▼]

Our study is founded on a multivariate approach to creativity. We analyze cognitive and personality variables in relationship to creative potential. The sample consists of 37 middle aged adults from the Grand Duchy of Luxembourg (20 women, 17 men, MAge = 41.03, SD = 7.23, age range: 29-55 years). Whereas ego-strength is positively related to creative potential, it is negatively related to psychoticism. We argue that in a population of academics psychoticism is not an essential condition for creative potential. It is rather the other side of the same coin. Ego-strength is some kind of moderator variable that determines which feature will be uncovered. We conceive that this ensues in three different forms of creativity. The first one relies on mental strength and emotional stability; the second one on emotional vulnerability and finally the third one arises from a confluence of both features. [less ▲]

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See detailMultivariate central limit theorems for averages of fractional Volterra processes and applications to parameter estimation
Nourdin, Ivan UL; Nualart, David; Zintout, Rola

Scientific journal (2015)

Detailed reference viewed: 61 (6 UL)
See detailMultivariate functional approximations with Stein's method of exchangeable pairs
Kasprzak, Mikolaj UL

E-print/Working paper (2017)

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See detailMultivariate Gaussian approxi- mations on Markov chaoses
Campese, Simon UL; Nourdin, Ivan UL; Peccati, Giovanni UL et al

in Electronic Communications in Probability (2016), 21

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See detailMultivariate integration of functions depending explicitly on the minimum and the maximum of the variables
Marichal, Jean-Luc UL

in De Baets, Bernard; Maes, Koen C.; Mesiar, Radko (Eds.) Proc. 4th Int. Summer School on Aggregation Operators and their Applications (AGOP 2007), Ghent, Belgium, July 9-14, 2007 (2007, July)

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See detailMultivariate integration of functions depending explicitly on the minimum and the maximum of the variables
Marichal, Jean-Luc UL

in Journal of Mathematical Analysis & Applications (2008), 341(1), 200-210

By using some basic calculus of multiple integration, we provide an alternative expression of the integral $$ \int_{]a,b[^n} f(\mathbf{x},\min x_i,\max x_i) \, d\mathbf{x}, $$ in which the minimum and the ... [more ▼]

By using some basic calculus of multiple integration, we provide an alternative expression of the integral $$ \int_{]a,b[^n} f(\mathbf{x},\min x_i,\max x_i) \, d\mathbf{x}, $$ in which the minimum and the maximum are replaced with two single variables. We demonstrate the usefulness of that expression in the computation of orness and andness average values of certain aggregation functions. By generalizing our result to Riemann-Stieltjes integrals, we also provide a method for the calculation of certain expected values and distribution functions. [less ▲]

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See detailMultivariate normal approximation using Stein's method and Malliavin calculus
Nourdin, Ivan UL; Peccati, Giovanni UL; Anthony, Réveillac

in Annales de l'Institut Henri Poincare (B) Probability & Statistics (2010), 46(1), 45--58

Detailed reference viewed: 79 (2 UL)