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The Simple Shear and Simple Tension Problems in Linear and Nonlinear Elasticity ; Bordas, Stéphane Report (2012) Detailed reference viewed: 143 (9 UL)A simple theory for the study of SDEs driven by a fractional Brownian motion, in dimension one Nourdin, Ivan in Lecture notes in Mathematics (2008) Detailed reference viewed: 94 (1 UL)"The Simplest Protocol for Oblivious Transfer'' Revisited Genç, Ziya Alper ; ; Rial, Alfredo in Information Processing Letters (2020) In 2015, Chou and Orlandi presented an oblivious transfer protocol that already drew a lot of attention both from theorists and practitioners due to its extreme simplicity and high efficiency. Chou and ... [more ▼] In 2015, Chou and Orlandi presented an oblivious transfer protocol that already drew a lot of attention both from theorists and practitioners due to its extreme simplicity and high efficiency. Chou and Orlandi claimed that their protocol is universally composable secure (UC-secure) in the random oracle model under dynamic corruptions. UC-security is a very strong security guarantee that assures that, not only the protocol in itself is secure, but can be also used safely in larger protocols. Unfortunately, in this work we point out a flaw in their security proof for the case of a corrupt sender. In more detail, we define a decisional problem and we prove that, if a correct security proof for the Chou and Orlandi's protocol is provided, then this problem can be solved correctly with overwhelming probability. Therefore, the protocol of Chou and Orlandi cannot be instantiated securely with groups for which our decisional problem cannot be solved correctly with overwhelming probability. Consequently, the protocol of Chou and Orlandi cannot be instantiated with {\em all} groups $\G$ in which the CDH problem is intractable, but only with groups in which both the CDH problem is intractable and our decisional problem can be solved with overwhelming probability. After the appearance of our work, Chou and Orlandi acknowledged the problems we pointed out in their security proof and subsequent works showed additional issues, removing the claims of UC security of their protocol. [less ▲] Detailed reference viewed: 73 (2 UL)Simplicial localization of homotopy algebras over a prop Yalin, Sinan in Mathematical Proceedings of the Cambridge Philosophical Society (2014), 157(3), 457468 We prove that a weak equivalence between two cofibrant (colored) props in chain complexes induces a Dwyer-Kan equivalence between the simplicial localizations of the associated categories of algebras ... [more ▼] We prove that a weak equivalence between two cofibrant (colored) props in chain complexes induces a Dwyer-Kan equivalence between the simplicial localizations of the associated categories of algebras. This homotopy invariance under base change implies that the homotopy category of homotopy algebras over a prop P does not depend on the choice of a cofibrant resolution of P, and gives thus a coherence to the notion of algebra up to homotopy in this setting. The result is established more generally for algebras in combinatorial monoidal dg categories. [less ▲] Detailed reference viewed: 21 (0 UL)A simplified and accelerated phase field method for crack nucleation and propagation in highly heterogeneous materials Nguyen, Thanh Tung ; ; et al in 20th European Conference on Fracture (2014) Detailed reference viewed: 19 (0 UL)A Simplified Approach to Computing Efficiency Bounds in Semiparametric Models ; Tripathi, Gautam in Journal of Econometrics (2001), 102 Detailed reference viewed: 126 (1 UL)Simplified density indexes of walls and tie-columns for confined masonry buildings in seismic zones Cai, Gaochuang ; ; et al in Journal of Earthquake Engineering (2017) This paper discusses and quantifies the minimum requirements of walls and tie-columns in confined masonry (CM) buildings located in earthquake-prone regions. A research database including 238 damaged CM ... [more ▼] This paper discusses and quantifies the minimum requirements of walls and tie-columns in confined masonry (CM) buildings located in earthquake-prone regions. A research database including 238 damaged CM buildings obtained from the 2008 Wenchuan earthquake survey is established and comprehensively examined. The requirements of masonry walls in CM buildings are discussed, and a simplified tie-column density index is proposed for evaluating the potential damage of the structures. Besides, the minimum requirements of reinforced concrete tie-columns and their maximum allowable spacing in CM buildings at different seismic intensity zones are discussed. [less ▲] Detailed reference viewed: 64 (1 UL)Simplified formation process for Cu2ZnSnS4-based solar cells Berg, Dominik ; Crossay, Alexandre ; et al in Thin Solid Films (2014), 573 Detailed reference viewed: 245 (1 UL)Simplified Reducibility Proofs of Church-Rosser for beta- and beta-eta-reduction ; Rahli, Vincent in Electronic Notes in Theoretical Computer Science (2009), 247 Detailed reference viewed: 47 (3 UL)Simulación Numérica de la Combustión en Lecho Estacionario Peters, Bernhard in Ingenieria Quimica -Madrid- (2000), 366 Detailed reference viewed: 52 (0 UL)Simulated and experimental results on heat recovery from hot steel beams in a cooling bed applying modified solar absorbers Tarrés Font, Joana ; Maas, Stefan ; Scholzen, Frank et al in Journal of Cleaner Production (2014), (68), 261-271 In recent years, the steel industry has undertaken efforts to increase energy efficiency by reducing energy consumption and recover otherwise lost heat. About 60% of the energy consumed in a steel plant ... [more ▼] In recent years, the steel industry has undertaken efforts to increase energy efficiency by reducing energy consumption and recover otherwise lost heat. About 60% of the energy consumed in a steel plant is lost in cooling beds where the hot steel beams are cooled down by natural convection and radiation. In this paper, the potential of heat recovery by radiation in a cooling bed was determined. Firstly, numerical simulations of the heat flux were done and validated with experimental measures. Secondly, a pilot test to recover the heat with modified solar absorbers was installed at the side of the cooling bed. The standard solar panels were painted with high absorption paint in the wavelength range of the hot beams. The results showed that up to 1 kW/m2 could be recovered with a temperature of 70°C at the side of the cooling bed, with a thermal efficiency of approximately 40%. As the experimental results were promising, further research is suggested to find an adequate selective coating and glazing. This would maximize the absorption at the wavelength range of the hot beams and minimize the emissivity at operational temperature of the absorber (100°C). Additionally, it would be of interest to find the optimum position for the absorbers in the cooling bed, which maximizes the heat recovery and does not interfere in the production process. [less ▲] Detailed reference viewed: 206 (11 UL)Simulating Communication Processes in Energy-Efficient Cloud Computing Systems Kliazovich, Dzmitry ; Bouvry, Pascal ; in CLOUDNET (2012) Cloud computing data centers are becoming increasingly popular for the provisioning of computing resources. The cost and operating expenses of data centers have skyrocketed with the increase in computing ... [more ▼] Cloud computing data centers are becoming increasingly popular for the provisioning of computing resources. The cost and operating expenses of data centers have skyrocketed with the increase in computing capacity. In this chapter, we survey the main techniques behind enabling energy efficiency in data centers and present simulation environment for energy-aware cloud computing. Along with the workload distribution, the focus is devoted to simulating packet-level communications in realistic setups. Finally, the effectiveness of common power management solutions is assessed and a scheduling methodology that combines energy efficiency and network awareness is presented. [less ▲] Detailed reference viewed: 133 (1 UL)Simulating Multi-graph Transformations Using Simple Graphs Hermann, Frank ; ; et al in Workshop on Graph Transformation and Visual Modelling Techniques (GT-VMT'07) (2007) Application of graph transformations for software verification and model transformation is an emergent field of research. In particular graph transformation approaches provide a natural way of modelling ... [more ▼] Application of graph transformations for software verification and model transformation is an emergent field of research. In particular graph transformation approaches provide a natural way of modelling object oriented systems and semantics of object-oriented languages. There exist a number of tools for graph transformations that are often specialised in a particular kind of graphs and/or graph transformation approaches, depending on the desired application domain. The main drawback of this diversity is the lack of interoperability. In this paper we show how (typed) multigraph production systems can be translated into (typed) simple-graph production systems. The presented construction enables the use of multigraphs with DPO transformation approach in tools that only support simple graphs with SPO transformation approach e.g. the GROOVE tool. [less ▲] Detailed reference viewed: 42 (2 UL)Simulating Realistic Mobility Models for Large Heterogeneous MANETs Hogie, Luc ; Bouvry, Pascal ; et al in 9th ACM/IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWIM'06) (2006) Detailed reference viewed: 80 (0 UL)Simulating topological changes in real time for surgical assistance Bordas, Stéphane ; ; et al Speeches/Talks (2016) Detailed reference viewed: 423 (38 UL)Simulation and computer-assisted analysis of actin cytoskeleton dynamics in living cells using fluorescence microscopy methods Halavatyi, Aliaksandr Doctoral thesis (2012) Controlled in time and space by a variety of actin-binding proteins, assembly and disassembly of the actin cytoskeleton is involved in many biological and biophysical phenomena. In order to understand the ... [more ▼] Controlled in time and space by a variety of actin-binding proteins, assembly and disassembly of the actin cytoskeleton is involved in many biological and biophysical phenomena. In order to understand the dynamics of such a complex intracellular system quantitative time-lapse imaging approaches are required. This thesis presents the results of the interdisciplinary project aimed at the quantitative evaluation of the effects of actin-binding proteins on actin turnover under physiological conditions. It combines fluorescence microscopy experiments, development of mathematical models and data processing tools to understand how regulatory proteins control actin dynamics. Confocal-microscopy-based Fluorescence Recovery After Photobleaching (FRAP) technique is a major experimental tool to measure the exchange of actin and actin-binding proteins between polymerised and monomeric pools. The developed models and computational algorithms allow to predict actin dynamics depending on regulatory proteins and to connect the experimental data to parameters characterising polymerisation dynamics, length and structures of actin filaments and activities of tested regulatory proteins. To test the models and to evaluate the activities of actin binding proteins without cellular constrains I combined quantitative FRAP analysis with a biomimetic assay which allows to reproduce major features of actin motility. This combination of techniques was utilised to measure the influence of previously characterised actin-binding proteins working together on actin dynamics in a concentration-dependent manner. In particular we investigated how capping and severing of actin filaments influences actin exchange in a bulk meshwork generated from spatially restricted nucleation. The experimental and analysis methods I developed were also used to investigate the dynamics of the actin cytoskeleton at focal adhesions of living cells. Taking as an example the focal adhesion protein zyxin and its binding partner Tes we addressed how the interactions of these proteins with actin regulate cytoskeleton dynamics. Taken together, the developed approaches and collected data help to better understand how regulatory proteins control actin dynamics in living cells. [less ▲] Detailed reference viewed: 108 (7 UL)Simulation and Performance Analysis of Data Intensive and Workload Intensive Cloud Computing Data Centers Kliazovich, Dzmitry ; Bouvry, Pascal ; in Kachris, Christoforos; Bergman, Keren; Tomkos, Ioannis (Eds.) Optical Interconnects for Future Data Center Networks (2013) Detailed reference viewed: 184 (2 UL)Simulation der aktiven Schwingungskontrolle von Fluid-Struktur Wechselwirkung durch piezoelektrische Materialien ; ; Zilian, Andreas in PAMM (2008), 8(1), 10529--10530 Ein numerisches Modell zur aktiven Kontrolle des dynamischen Verhaltens von Tragwerken unter transienter Windeinwirkung wird vorgestellt. Auf der Oberschicht passiver Tragstrukturen werden ... [more ▼] Ein numerisches Modell zur aktiven Kontrolle des dynamischen Verhaltens von Tragwerken unter transienter Windeinwirkung wird vorgestellt. Auf der Oberschicht passiver Tragstrukturen werden piezoelektrische Sensoren und Aktoren appliziert. Die resultierenden adaptierbaren Strukturen sind mit einem Regler gekoppelt. Die Modellierung der elektroelastischen Struktur erfolgt mit der geometrisch nichtlinearen Elastizitätstheorie und der Maxwell–Faraday–Theorie der Elektrostatik. Die Windumströmung der Struktur ist als inkompressibles, Newton'sches Fluid mit den Navier–Stokes–Gleichungen beschrieben. Die Diskretisierung der gekoppelten Modellgleichungen beider Kontinua erfolgt mit finiten Raum–Zeit–Elementen. Zeitliche Änderungen der Zustandsgrößen werden mit dem diskontinuierlichen Galerkin–Verfahren approximiert. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [less ▲] Detailed reference viewed: 120 (1 UL)Simulation des Traktionsverhaltens von Reifen auf granularem Untergrund durch eine Kopplung zwischen der Finiten (FEM) und der Diskreten Element Methode (DEM) Michael, Mark ; Peters, Bernhard ; in VDI-Berichte "Reifen-Fahrwerk-Fahrbahn" (2013, October) Kurzfassung Innerhalb dieses Beitrags wird die numerische Simulationsmethode der Extended Discrete Element Methode (XDEM) vorgestellt, mit der die Wechselwirkung zwischen Reifen und steinigem Untergrund ... [more ▼] Kurzfassung Innerhalb dieses Beitrags wird die numerische Simulationsmethode der Extended Discrete Element Methode (XDEM) vorgestellt, mit der die Wechselwirkung zwischen Reifen und steinigem Untergrund detailliert beschrieben werden kann. Dabei wird der Reifen als ein Kontinuum betrachtet, das mit der Finiten Element Methode (FEM) abgebildet wird. Der grobkörnige Untergrund, wie beispielsweise Sand oder Kies, wird als granulares Medium betrachtet. Dieses kann sehr vorteilhaft mit der Diskreten Element Methode (DEM) behandelt werden, die eine Betrachtung der individuellen Partikel zulässt. Basierend auf den Gesetzen von Newton werden Position und Orientierung aller Partikel berechnet, wobei Kräfte zwischen den Partikeln und dem Reifen berücksichtigt werden. Kräfte zwischen Partikeln und Reifen treten als Randbedingungen in der FEM Struktur des Reifens auf, und führen damit zur Deformation und somit zu Spannungverteilung in der Reifenstrucktur. Eine Integration in der Zeit bestimmt sowohl den Zustand des Untergrunds als auch die Reaktion des Reifens. Dies wird durch eine innovative Kopplung zwischen der Discrete Particle Method (DPM) zur Beschreibung des granularen Mediums und dem Finite Element Löser DiffPACK erreicht und deshalb als Extended Discrete Element Methode bezeichnet wird. Beides sind objekt- orientierte Software-Werkzeuge, die über eine Schnittstelle die notwendigen Daten austauschen, so dass der Anwender sein Augenmerk auf die Problemlösung richten kann als sich mit Datenaustausch und Algorithmen zu befassen. Damit wurde ein vielseitiges und flexibles Werkzeug zur Lösung vielfältiger Probleme wie auch die Bewegung eines Reifens im Schnee geschaffen. Das neuartige Konzept ist sowohl auf Windows als auch auf UNIX basierenden Betriebssystemen verfügbar. Abstract The objective of this contribution is to resolve different length scales in structure analysis by an interface coupling the Discrete Element Method (DEM) with the Finite Element Method (FEM) and therefore, is labelled Extended Discrete Element Methode (XDEM). This approach distinguishes itself from other methods in so far that no overlapping domains between Finite and Discrete Elements exist. Both domains are separated in physical space and numerical simulation domain. The proposed approach is relevant to almost all engineering applications that deal with granular matter such as storage in hoppers, transport on conveyor belts or displacement of granular material as in mixers or excavation of soil. For these applications an engineering device such as mixer blades or cutting tools are in contact with granular matter. Contacts with individual particles generate contact forces that act on both the engineering device and the granular material. The latter experiences a displacement of individual particles whereby the engineering structure responds with deformation and stresses. In order to predict and optimize both the behaviour and motion of granular material and the structures in contact, numerical simulation tools are increasingly employed [1]. Simulations are popular especially because experiments which are often expensive, time- consuming and sometimes even dangerous [2]. The continuous increase in computing power is now enabling researchers to implement numerical methods that do not focus on the granular assembly as an entity, but rather deduce its global characteristics from observing the individual behaviour of each grain. An interaction between granular media and a structure relies on a transfer of forces between them. Granular media consists of an ensemble of particles of which a number of particles may be in contact with a surface e.g. walls as surfaces of solid structures. The contact is resolved similar to inter-particle contacts by a representative overlap. It defines the position of impact as well as the force acting on the particle at this position. The same force, however, into the opposite direction defines a mechanical load for the structure. In order to determine the effect of forces on the solid structure, it is discretised by finite elements. The impact of the force is transferred to the nodes of the respective surface element and appears as a load for the finite element system. Hence, integrating particle dynamics and the response of the solid structure due to particle impacts advances both new position of particles and corresponding deformation and stress of the solid structure in time. Developing flexible software which is capable of performing simulation in different applications will enable the engineers to focus entirely on their specific problem and hence save them valuable time. This concept is supported by the software tools of the Discrete Particle Method (DPM) and Diffpack. Hence, the solid structure is analysed by the Finite Element Method under load due to the impact of individual particles that changes both in time and space. For this purpose traditional formulations of the Finite Element Method are employed that are available by the commercial multi-physics software package Diffpack. It represents object-oriented hierarchy of classes that provide an excellent interface to introduce external loads from particle impact onto the finite element structure. Diffpack is an object-oriented development environment, which comes as a rich set of C++ classes, for the numerical modelling and solution of arbitrary differential equations. User applications cover a wider range of engineering areas and span from simple educational applications to major product development projects. The behaviour of granular material is represented by the advanced software package of the Discrete Particle Method (DPM), which is based on the Discrete Element Method. It is designed to relieve users from underlying mathematics and software design and allows them to focus on physics and their applications. The software uses object oriented techniques that support objects representing three-dimensional particles of various shapes such as cylinders, discs or tetrahedrons for example, size and material properties. This makes it a highly versatile tool dealing with a large variety of different applications of granular matter arising in the automotive industry, such as road tire interaction. Various force models for the inter- particle and particle-wall contacts are also available. A minimal user interface easily allows extending the software further by adding user-defined impact models or material properties to an already available selection of materials and properties. Thus, the user is relieved of the underlying mathematics or software design, and therefore, is able to direct his focus entirely onto the application. The Discrete Particle Method is written in C++ programming language and works both in Linux and Windows environments. [less ▲] Detailed reference viewed: 291 (9 UL)Simulation of condensation in a inclined tube with ATHLET code Zhang, Yu ; Leyer, Stephan Presentation (2017, September 13) Detailed reference viewed: 52 (1 UL) |
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