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See detailSynthesis, theoretical and experimental characterisation of thin film Cu2Sn1-xGexS3 ternary alloys (x = 0 to 1): Homogeneous intermixing of Sn and Ge
Robert, Erika UL; Gunder, René; De Wild, Jessica UL et al

in Acta Materialia (2018), 151

Cu2Sn1-xGexS3 is a p-type semiconductor alloy currently investigated for use as an absorber layer in thin film solar cells. The aim of this study is to investigate the properties of this alloy in thin ... [more ▼]

Cu2Sn1-xGexS3 is a p-type semiconductor alloy currently investigated for use as an absorber layer in thin film solar cells. The aim of this study is to investigate the properties of this alloy in thin film form in order to establish relationships between group IV composition and structural, vibrational and opto-electronic properties. Seven single phase Cu2Sn1-xGexS3 films are prepared from x ¼ 0 to 1, showing a uniform distribution of Ge and Sn laterally and in depth. The films all show a monoclinic crystal structure. The lattice parameters are extracted using Le Bail refinement and show a linear decrease with increasing Ge content. Using density-functional theory with hybrid functionals, we calculate the Raman active phonon frequencies of Cu2SnS3 and Cu2GeS3. For the alloyed compounds, we use a virtual atom approximation. The shift of the main Raman peak from x ¼ 0 to x ¼ 1 can be explained as being half due to the change in atomic masses and half being due to the different bond strength. The bandgaps of the alloys are extracted from photoluminescence measurements and increase linearly from about 0.90 to 1.56 eV with increasing Ge. The net acceptor density of all films is around 1018 cm 3. These analyses have established that the alloy forms a solid solution over the entire composition range meaning that intentional band gap grading should be possible for future absorber layers. The linear variation of the unit cell parameters and the band gap with group IV content allows composition determination by scattering or optical measurements. Further research is required to reduce the doping density by two orders of magnitude in order to improve the current collection within a solar cell device structure. [less ▲]

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See detailPathologies of Empathy: Kant, Polidori, Hoffmann
Kohns, Oliver UL

Scientific Conference (2018, April)

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See detailNon-Negative Paratuck2 Tensor Decomposition Combined to LSTM Network for Smart Contracts Profiling
Charlier, Jérémy Henri J. UL; State, Radu UL

in International Journal of Computer & Software Engineering (2018), 3(1),

Background: Past few months have seen the rise of blockchain and cryptocurrencies. In this context, the Ethereum platform, an open-source blockchain-based platform using Ether cryptocurrency, has been ... [more ▼]

Background: Past few months have seen the rise of blockchain and cryptocurrencies. In this context, the Ethereum platform, an open-source blockchain-based platform using Ether cryptocurrency, has been designed to use smart contracts programs. These are self-executing blockchain contracts. Due to their high volume of transactions, analyzing their behavior is very challenging. We address this challenge in our paper. Methods: We develop for this purpose an innovative approach based on the non-negative tensor decomposition Paratuck2 combined with long short-term memory. The objective is to assess if predictive analysis can forecast smart contracts activities over time. Three statistical tests are performed on the predictive analytics, the mean absolute percentage error, the mean directional accuracy and the Jaccard distance. Results: Among dozens of GB of transactions, the Paratuck2 tensor decomposition allows asymmetric modeling of the smart contracts. Furthermore, it highlights time dependent latent groups. The latent activities are modeled by the long short term memory network for predictive analytics. The highly accurate predictions underline the accuracy of the method and show that blockchain activities are not pure randomness. Conclusion: Herein, we are able to detect the most active contracts, and predict their behavior. In the context of future regulations, our approach opens new perspective for monitoring blockchain activities. [less ▲]

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See detailUn crépuscule pour réveiller l'histoire
Scuto, Denis UL

Article for general public (2018)

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See detailContested Autonomies: French University Governance and its Discontents
Harmsen, Robert UL

Scientific Conference (2018, March 28)

In the past decade, the governance of French universities has seen substantial changes in line with developments elsewhere in Europe. Engaging in an ‘autonomy/accountability two-step’, French universities ... [more ▼]

In the past decade, the governance of French universities has seen substantial changes in line with developments elsewhere in Europe. Engaging in an ‘autonomy/accountability two-step’, French universities have been granted a significantly higher degree of organisational autonomy while at the same time becoming subject to a widening set of external accountability measures. The French case nonetheless presents interesting specificities stemming particularly from the absence of a strong tradition of institutional-level university autonomy. The present paper explores current reforms against the background of this distinctive historical tradition, probing the mediation of ‘global scripts’ by ‘national filters’. After setting out the broad contours of the historical model, successive sections then survey the 2007 Law on the Liberty and Responsibility of Universities, the 2013 Fioraso Law, and the possible direction of policy under the Macron presidency. The concluding section situates French developments relative to wider trends in terms suggestive of a forward research agenda. [less ▲]

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See detailÊtre d'ailleurs en temps de guerre
Scuto, Denis UL

Article for general public (2018)

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See detailRudolf Seidel, Léon Metz et la Halle des soufflantes
Scuto, Denis UL

Article for general public (2018)

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See detailSpaces – different modes of space in towns
Pauly, Michel UL; Scheutz, Martin

in Fray, Jean-Luc; Pauly, Michel; Pinheiro, Magda (Eds.) et al Urban Spaces and the complexity of Cities (2018)

introduction to the volume stressing the importance of the spatial turn in urban history and the complexity of towns

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See detailSecretion of the Phosphorylated Form of S100A9 from Neutrophils Is Essential for the Proinflammatory Functions of Extracellular S100A8/A9.
Schenten, Veronique; Plancon, Sebastien; Jung, Nicolas UL et al

in Frontiers in immunology (2018), 9

S100A8 and S100A9 are members of the S100 family of cytoplasmic EF-hand Ca(2+)-binding proteins and are abundantly expressed in the cytosol of neutrophils. In addition to their intracellular roles, S100A8 ... [more ▼]

S100A8 and S100A9 are members of the S100 family of cytoplasmic EF-hand Ca(2+)-binding proteins and are abundantly expressed in the cytosol of neutrophils. In addition to their intracellular roles, S100A8/A9 can be secreted in the extracellular environment and are considered as alarmins able to amplify the inflammatory response. The intracellular activity of S100A8/A9 was shown to be regulated by S100A9 phosphorylation, but the importance of this phosphorylation on the extracellular activity of S100A8/A9 has not yet been extensively studied. Our work focuses on the impact of the phosphorylation state of secreted S100A9 on the proinflammatory function of neutrophils. In a first step, we characterized the secretion of S100A8/A9 in different stimulatory conditions and investigated the phosphorylation state of secreted S100A9. Our results on neutrophil-like differentiated HL-60 (dHL-60) cells and purified human neutrophils showed a time-dependent secretion of S100A8/A9 when induced by phorbol 12-myristoyl 13-acetate and this secreted S100A9 was found in a phosphorylated form. Second, we evaluated the impact of this phosphorylation on proinflammatory cytokine expression and secretion in dHL-60 cells. Time course experiments with purified unphosphorylated or phosphorylated S100A8/A9 were performed and the expression and secretion levels of interleukin (IL)-1alpha, IL-1beta, IL-6, tumor necrosis factor alpha, CCL2, CCL3, CCL4, and CXCL8 were measured by real-time PCR and cytometry bead array, respectively. Our results demonstrate that only the phosphorylated form of the complex induces proinflammatory cytokine expression and secretion. For the first time, we provide evidence that S100A8/PhosphoS100A9 is inducing cytokine secretion through toll-like receptor 4 signaling. [less ▲]

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See detailA Simple Engineering Soil Surface Vibration Prediction Method
Macijauskas, Darius UL; Van Baars, Stefan UL

in Civil Engineering Research Journal (2018), 4(2),

In urban areas where the infrastructure is dense and construction of new structures is near existing and sensitive buildings, frequently vibrations, caused by human activities, occur. Generated waves in ... [more ▼]

In urban areas where the infrastructure is dense and construction of new structures is near existing and sensitive buildings, frequently vibrations, caused by human activities, occur. Generated waves in the soil may adversely affect surrounding buildings. These vibrations have to be predicted a priori by using currently available knowledge of the soil dynamics. In order to make a good prediction of the soil surface vibration, it is necessary to perform calculations with a Finite Element Method (FEM). The disadvantages of the FEM are that this requires a special software package and a long time for the modelling and calculations. Therefore, it would be very useful to derive a simple model for engineering purposes, which could be used to predict geotechnical vibrations close to the source, without the need of special software and long calculations. Such a method is proposed in this article. This method is validated by a vibration test performed on a peaty site in the Netherlands. The predictions made with this method, have been compared with both the field measurements and the FEM calculations. The comparison proves that by using the presented vibration prediction method, the vibrations can be predicted as accurate as with the FEM. [less ▲]

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See detailEU 'Horizontal' Report
Ligeti, Katalin UL; Marletta, Angelo UL

in Vervaele, John; Simonato, Michele; Luchtman, Michiel (Eds.) Exchange of information with EU and national enforcement authorities. Improving OLAF legislative framework through a comparison with other EU authorities (ECN/ESMA/ECB) (2018)

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See detailFunds and EU Tax Directives
Pantazatou, Aikaterini UL

in Haslehner, Werner (Ed.) Investment Fund Taxation (2018)

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See detailBayesian optimization to enhance coverage performance of a swarm of UAV with chaotic dynamics
Kieffer, Emmanuel UL; Rosalie, Martin UL; Danoy, Grégoire UL et al

Scientific Conference (2018, February 26)

We introduce the optimization of CACOC through Bayesian Optimization. CACOC is based on a chaotic system, i.e. Rossler system whose behavior can be modified by tuning the α parameter. In order to evaluate ... [more ▼]

We introduce the optimization of CACOC through Bayesian Optimization. CACOC is based on a chaotic system, i.e. Rossler system whose behavior can be modified by tuning the α parameter. In order to evaluate the performance of CACOC for different value of α, the coverage metric has to be evaluated after simulation. The latter is time-consuming. Therefore, a surrogate-based optimization, i.e. Bayesian Optimization has been privilegied to tackle this issue. An analysis of the chaotic system with the obtained α value has been performed to compare the periodic orbits and their associated patterns. Numerical results show that the best α value avoid a waste of time in periodic region of the bifurcation diagram. Future works will focus on more complex chaotic system as well as new application domain of the optimized CACOC approach. [less ▲]

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See detailLe patrimoine industriel: Objet de nostalgie ou sujet de recherche?
Scuto, Denis UL

Speeches/Talks (2018)

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See detailL'ère du témoin
Scuto, Denis UL

Article for general public (2018)

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See detailExploring Different Assessment Techniques of the Test for Creative Thinking – Drawing Production
Kirsch, Christiane; Lubart, Todd; Houssemand, Claude UL

in Collange, Julie; Loarer, Even; Lubart, Todd (Eds.) 1/118 La psychologie différentielle au 21 ème siècle : nouvelles modélisations et applications (2018)

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See detailBlockchain Orchestration and Experimentation Framework: A Case Study of KYC
Shbair, Wazen UL; Steichen, Mathis Georges UL; François, Jérôme UL et al

in The First IEEE/IFIP International Workshop on Managing and Managed by Blockchain (Man2Block) colocated with IEEE/IFIP NOMS 2018 (2018)

Conducting experiments to evaluate blockchain applications is a challenging task for developers, because there is a range of configuration parameters that control blockchain environments. Many public ... [more ▼]

Conducting experiments to evaluate blockchain applications is a challenging task for developers, because there is a range of configuration parameters that control blockchain environments. Many public testnets (e.g. Rinkeby Ethereum) can be used for testing, however, we cannot adjust their parameters (e.g. Gas limit, Mining difficulty) to further the understanding of the application in question and of the employed blockchain. This paper proposes an easy to use orchestration framework over the Grid'5000 platform. Grid'5000 is a highly reconfigurable and controllable large-scale testbed. We developed a tool that facilitates nodes reservation, deployment and blockchain configuration over the Grid'5000 platform. In addition, our tool can fine-tune blockchain and network parameters before and between experiments. The proposed framework offers insights for private and consortium blockchain developers to identify performance bottlenecks and to assess the behavior of their applications in different circumstances. [less ▲]

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