http://hdl.handle.net/10993/91 Search this channel search https://orbilu.uni.lu/simple-search http://hdl.handle.net/10993/43984 Title: Dynamic pricing using wavelet neural network under uncertain demands <br/> <br/>Author, co-author: Sadegh AmalNick, Mohsen; Qorbanian, Roozbeh Thu, 06 Aug 2020 03:30:06 GMT http://hdl.handle.net/10993/43954 Title: Developing an Interactive Tabletop Mediated Activity to Induce Collaboration by Implementing Design Considerations Based on Cooperative Learning Principles <br/> <br/>Author, co-author: Sunnen, Patrick; Arend, Béatrice; Heuser, Svenja; Afkari, Hoorieh; Maquil, Valérie <br/> <br/>Abstract: Constructive collaboration can be a difficult matter. For this reason, we are implementing and studying an interactive-tabletop-mediated activity that aims at inducing collaboration among participants. The resulting activity ‘Orbitia’ is designed as a serious game. Participants are asked to act as a space- mining crew, which has to collect minerals with a rover and rely on a camera- drone for reconnaissance, while keeping the rover out of harm and managing limited resources. In this paper we provide an account of how we designed Orbitia’s pedagogical structuring by relying on the Johnsons’ cooperative learning approach whose fundamental concept is “positive interdependence”. More particularly, we show how we worked on resource, role and task inter- dependence to design three collaboration-inducing ‘flagship’ devices: the rover- steering-device (RSD), the item-locating-device (ILD) and the responsibility- activating-device (RAD). Fri, 31 Jul 2020 12:26:08 GMT http://hdl.handle.net/10993/43484 Title: The stochastic maintenance location routing allocation problem for rolling stock <br/> <br/>Author, co-author: Tönissen, Denise; Arts, Joachim Fri, 12 Jun 2020 10:28:12 GMT http://hdl.handle.net/10993/43469 Title: Finite deformations govern the anisotropic shear-induced area reduction of soft elastic contacts <br/> <br/>Author, co-author: Lengiewicz, Jakub; de Souza, Mariana; Lahmar, Mohamed A.; Courbon, Cédric; Dalmas, Davy; Stupkiewicz, Stanislaw; Scheibert, Julien <br/> <br/>Abstract: Solid contacts involving soft materials are important in mechanical engineering or biomechanics. Experimentally, such contacts have been shown to shrink significantly under shear, an effect which is usually explained using adhesion models. Here we show that quantitative agreement with recent high-load experiments can be obtained, with no adjustable parameter, using a non-adhesive model, provided that finite deformations are taken into account. Analysis of the model uncovers the basic mechanisms underlying anisotropic shear-induced area reduction, local contact lifting being the dominant one. We confirm experimentally the relevance of all those mechanisms, by tracking the shear-induced evolution of tracers inserted close to the surface of a smooth elastomer sphere in contact with a smooth glass plate. Our results suggest that finite deformations are an alternative to adhesion, when interpreting a variety of sheared contact experiments involving soft materials. Wed, 10 Jun 2020 13:48:39 GMT http://hdl.handle.net/10993/43237 Title: Isogeometric analysis of thin Reissner-Mindlin shells: locking phenomena and B-bar method <br/> <br/>Author, co-author: Hu, Qingyuan; Xia, Yang; Natarajan, Sundararajan; Zilian, Andreas; Hu, Ping; Bordas, Stéphane <br/> <br/>Abstract: We propose a local type of B-bar formulation, addressing locking in degenerated Reissner–Mindlin shell formulation in the context of isogeometric analysis. Parasitic strain components are projected onto the physical space locally, i.e. at the element level, using a least-squares approach. The formulation allows the flexible utilization of basis functions of different orders as the projection bases. The introduced formulation is much cheaper computationally than the classical $$\bar{B}$$B¯ method. We show the numerical consistency of the scheme through numerical examples, moreover they show that the proposed formulation alleviates locking and yields good accuracy even for slenderness ratios of $$10^5$$105, and has the ability to capture deformations of thin shells using relatively coarse meshes. In addition it can be opined that the proposed method is less sensitive to locking with irregular meshes. Fri, 22 May 2020 03:30:02 GMT http://hdl.handle.net/10993/43032 Title: La Fabrication Additive Robotisée: Perspective et Recherche autour d'Impression 3D de Pièces Métalliques de Grandes Dimensions pour l'Industrie Aéronautique <br/> <br/>Author, co-author: Mbodj, Natago Guilé; Plapper, Peter Tue, 28 Apr 2020 15:22:37 GMT http://hdl.handle.net/10993/43025 Title: Viviane Reding on her action in the field of the information society and media (2004-2010) <br/> <br/>Author, co-author: Danescu, Elena <br/> <br/>Abstract: The following pages are taken from a long interview (more than eight hours of footage in total) that Viviane Reding granted us in 2015 in connection with the “Pierre Werner and Europe” research project. Drawing on more than 40 years’ experience in politics, Viviane Reding spoke about her career, the role of Luxembourg and Luxembourgers in the European integration process, and various key events in which she played a part. In these extracts, she discusses her role as a member of the first and second Barroso Commissions (2004-2009 and 2010-2014) and her efforts to help build an information and knowledge society in Europe, one that serves citizens and protects their rights and fundamental freedoms. Her achievements in this respect include capping mobile phone roaming charges (they were subsequently abolished in 2017), advocating for the introduction of a single emergency number (112) in all EU countries, launching the Europeana digital library, and spearheading a programme to use technological innovation for climate and energy solutions. She also describes the process of developing a Digital Agenda for Europe to improve the continent’s digital competitiveness compared with the United States, China and Japan – a complex and challenging task given the context of globalisation and the divergent interests of the various stakeholders (research, industry, consumers, etc.). Finally, she mentions the reform of personal data protection that she initiated (leading to the GDPR, adopted in April 2016). Sun, 26 Apr 2020 18:23:36 GMT http://hdl.handle.net/10993/42986 Title: Clustering Based Model Order Reduction For Hyper Elastoplastic Material Models <br/> <br/>Author, co-author: Vijayaraghavan, Soumianarayanan; Beex, Lars; Noels, Ludovic; Bordas, Stéphane Mon, 20 Apr 2020 06:33:31 GMT http://hdl.handle.net/10993/42937 Title: Machine Learning to Geographically Enrich Understudied Sources: A Conceptual Approach <br/> <br/>Author, co-author: Viola, Lorella; Verheul, Jaap <br/> <br/>Abstract: This paper discusses the added value of applying machine learning (ML) to contextually enrich digital collections. In this study, we employed ML as a method to geographically enrich historical datasets. Specifically, we used a sequence tagging tool (Riedl and Padó 2018) which implements TensorFlow to perform NER on a corpus of historical immigrant newspapers. Afterwards, the entities were extracted and geocoded. The aim was to prepare large quantities of unstructured data for a conceptual historical analysis of geographical references. The intention was to develop a method that would assist researchers working in spatial humanities, a recently emerged interdisciplinary field focused on geographic and conceptual space. Here we describe the ML methodology and the geocoding phase of the project, focussing on the advantages and challenges of this approach, particularly for humanities scholars. We also argue that, by choosing to use largely neglected sources such as immigrant newspapers (a lso known as ethnic newspapers), this study contributes to the debate about diversity representation and archival biases in digital practices. Wed, 08 Apr 2020 09:19:03 GMT http://hdl.handle.net/10993/42934 Title: Against mass media trends: Minority growth in cultural globalization <br/> <br/>Author, co-author: Cosenza, M. G.; Gavidia Borrero, Marino Eliezer; Gonzalez-Avella, J. C. <br/> <br/>Abstract: We investigate the collective behavior of a globalized society under the influence of endogenous mass media trends. The mass media trend is a global field corresponding to the statistical mode of the states of the agents in the system. The interaction dynamics is based on Axelrod’s rules for the dissemination of culture. We find situations where the largest minority group, possessing a cultural state different from that of the predominant trend transmitted by the mass media, can grow to almost half of the size of the population. We show that this phenomenon occurs when a critical number of long-range connections are present in the underlying network of interactions. We have numerically characterized four phases on the space of parameters of the system: an ordered phase; a semi-ordered phase where almost half of the population consists of the largest minority in a state different from that of the mass media; a disordered phase; and a chimera-like phase where one large domain coexists with many very small domains. Tue, 07 Apr 2020 09:25:42 GMT http://hdl.handle.net/10993/42905 Title: Cybermenaces, enjeux et sécurité : entretien avec Stéphane Bortzmeyer et Mohsen Souissi (Afnic) <br/> <br/>Author, co-author: Schafer, Valerie <br/> <br/>Abstract: Si les cyberattaques récentes au Moyen-Orient, menées via les noms de domaine, ont eu un vaste écho médiatique fin février 2019, tandis que la revue Défense et Sécurité Internationale consacrait un dossier spécial à la techno-guérilla, les menaces qui pèsent sur les réseaux informatiques ne sont pas nouvelles. L’Afnic – Association Française pour le Nommage Internet en Coopération –, gestionnaire historique du .fr, fait partie des acteurs français confrontés au quotidien aux enjeux de sécurité des réseaux Internet et veille notamment à la sécurité des noms de domaine et au bon fonctionnement du .fr, en terme de disponibilité mais aussi d’intégrité. Mohsen Souissi, alors Responsable des Sécurité des Sys- tèmes d’information (RSSI) à l’Afnic, qu’il a intégrée en 2000 et où il était précédemment responsable Recherche et développement (R&D) de 2007 à 2016, et Stéphane Bortzmeyer, auteur de Cyberstructure (C&F Éditions, 2018) et ingénieur à l’Afnic depuis seize ans, après avoir été administrateur pour plusieurs systèmes et réseaux universitaires et de centres de recherche, reviennent sur les cybermenaces et les enjeux de sécurité auxquels ils sont confrontés. Sat, 04 Apr 2020 22:26:57 GMT http://hdl.handle.net/10993/42861 Title: Crafting Conversational Agents' Personality in a User-Centric Context <br/> <br/>Author, co-author: Mano Ferreira, Cátia; Höhn, Sviatlana Fri, 27 Mar 2020 13:03:33 GMT http://hdl.handle.net/10993/42720 Title: Process analysis in thermal process engineering with high-performance computing using the example of grate firing <br/> <br/>Author, co-author: Peters, Bernhard; Rousset, Alban; Besseron, Xavier; Mainassara Chekaraou, Abdoul Wahid; Maria Grazia, Gallo; Franco, Sansone; Alesio, Lupi; Chiara, Galleti <br/> <br/>Abstract: Biomass as a renewable energy source continues to grow in popularity to reduce fossil fuel consumption for environmental and economic benefits. In the present contribution, the combustion chamber of a 16 MW geothermal steam super-heater, which is part of the Enel Green Power "Cornia 2" power plant, is being investigated with high-performance computing methods. For this purpose, the extended discrete element method (XDEM) developed at the University of Luxembourg is used in a high-performance computing environment, which includes both the moving wooden bed and the combustion chamber above it. The XDEM simulation platform is based on a hybrid four-way coupling between the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD). In this approach, particles are treated as discrete elements that are coupled by heat, mass, and momentum transfer to the surrounding gas as a continuous phase. For individual wood particles, besides the equations of motion, the differential conservation equations for mass, heat, and momentum are solved, which describe the thermodynamic state during thermal conversion. The consistency of the numerical results with the actual system performance is discussed in this paper to determine the potentials and limitations of the approach. Wed, 04 Mar 2020 07:55:00 GMT http://hdl.handle.net/10993/42704 Title: Mensch-Roboter-Kollaboration in der Domäne Refabrikation – State-of-the-Art und Ausblick <br/> <br/>Author, co-author: Groß, Sebastian; Gerke, Wolfgang; Plapper, Peter Mon, 02 Mar 2020 16:21:43 GMT http://hdl.handle.net/10993/42703 Title: Agentenbasierte, hybride Steuerungsarchitektur für cyberphysische Refabrikationssysteme <br/> <br/>Author, co-author: Groß, Sebastian; Gerke, Wolfgang; Plapper, Peter Mon, 02 Mar 2020 16:17:19 GMT http://hdl.handle.net/10993/42677 Title: DATA DRIVEN SURGICAL SIMULATIONS <br/> <br/>Author, co-author: Deshpande, Saurabh; Bordas, Stéphane; Beex, Lars; Cotin, Stephane; Sarkica, Anina Sun, 01 Mar 2020 04:30:05 GMT http://hdl.handle.net/10993/42601 Title: Real Time Holding Control for Multiline Networks <br/> <br/>Author, co-author: Laskaris, Georgios; Cats, Oded; Jenelius, Erik; Rinaldi, Marco; Viti, Francesco <br/> <br/>Abstract: We introduce a rule based multiline holding criterion for regularity in branch and trunk networks accounting for all passenger groups. On the shared transit corridor, we consider synchronization at the merging or the diverging stop. The decision between holding for regularity or synchronization is taken by comparing the expected passenger cost of each control action. The proposed criterion is tested through simulation in a synthetic double fork network with different shares of transferring passengers, control schemes for regularity and synchronization. The results show that multiline control outperforms the state of the art schemes at the network level, stemming from benefits occurring at the first part of the route and the shared transit corridor and a 3.5% more stable joint headway compared to the other schemes. Additionally, it is advised to perform the synchronization at the diverging stop, as it proves to result in a more stable transferring time equal to the joint frequency of the corridor while reducing the transfer time variability up to -42.7%. Sat, 22 Feb 2020 04:30:03 GMT http://hdl.handle.net/10993/42592 Title: Data Centric Engineering and Data-Driven Modelling - Computational Engineering Lab Report 2019 <br/> <br/>Author, co-author: Bordas, Stéphane; Peters, Bernhard; Viti, Francesco; Zilian, Andreas <br/> <br/>Abstract: https://www.cambridge.org/core/journals/data-centric-engineering Fri, 21 Feb 2020 04:30:06 GMT http://hdl.handle.net/10993/42591 Title: Active Content Popularity Learning via Query-by-Committee for Edge Caching <br/> <br/>Author, co-author: Bommaraveni, Srikanth; Vu, Thang; Vuppala, Satyanarayana; Chatzinotas, Symeon; Ottersten, Björn <br/> <br/>Abstract: Edge caching has received much attention as an effective solution to face the stringent latency requirements in 5G networks due to the proliferation of handset devices as well as data-hungry applications. One of the challenges in edge caching systems is to optimally cache strategic contents to maximize the percentage of total requests served by the edge caches. To enable the optimal caching strategy, we propose an Active Learning approach (AL) to learn and design an accurate content request prediction algorithm. Specifically, we use an AL based Query-by-committee (QBC) matrix completion algorithm with a strategy of querying the most informative missing entries of the content popularity matrix. The proposed AL framework leverage's the trade-off between exploration and exploitation of the network, and learn the user's preferences by posing queries or recommendations. Later, it exploits the known information to maximize the system performance. The effectiveness of proposed AL based QBC content learning algorithm is demonstrated via numerical results. Fri, 21 Feb 2020 04:30:05 GMT http://hdl.handle.net/10993/42546 Title: Removing the saturation assumption in Bank-Weiser error estimator analysis in dimension three <br/> <br/>Author, co-author: Bulle, Raphaël; Chouly, Franz; Hale, Jack; Lozinski, Alexei <br/> <br/>Abstract: We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes the main novelty of our study. In addition, we present a numerical comparison of the Bank-Weiser and residual estimators for a three-dimensional test case. Tue, 18 Feb 2020 10:04:11 GMT