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See detailChemical Bonds in Laser Welded Aluminum and Polyamide
Hirchenhahn, Pierre; Al Sayyad, Adham UL; Bardon, Julien et al

Presentation (2017, September 14)

Automotive industry is showing an increasing interest towards polymer/metal assemblies, essentially in order to increase fuel efficiency through the reduction of car body weight. In parallel, these ... [more ▼]

Automotive industry is showing an increasing interest towards polymer/metal assemblies, essentially in order to increase fuel efficiency through the reduction of car body weight. In parallel, these assemblies are interesting for biomedical applications, because of the potential to obtain improved or new properties e.g. for implants. Laser welding is considered one of the most promising methods of joining dissimilar materials because of its unique advantages; the process is fast, can be adapted to complex geometries and is totally solvent free, which is a major asset for biomedical applications [1]. A strong adhesion between polyamide 6.6 (PA-6.6) and aluminum (Al) plates was obtained from laser welding in optimized conditions [2]. However, the root causes of this adhesion are not yet understood. Several effects may come into play, such as covalent binding, electrostatic binding, interdiffusion and mechanical interlocking. This is further complicated in “real life” samples by the high roughness of the metal sheet, the additives contained in the polymer, the Al and PA-6.6 surface composition and the difficulty to reach the metal-polymer interface. In order to gain information on the chemical binding between the oxydized Al surface and the PA-6.6, model samples were prepared by spin coating ultrathin PA-6.6 films on polished Al (99.999 % purity) plates (Fig. 1.). The two materials were subsequently welded by laser irradiation. FT-IR, XPS and ToF-SIMS have been used to carry out this study. The interface was reached by sputtering the polymer with low energy Cs+ ions in ToF-SIMS and Ar clusters GCIB in XPS. In this preliminary study, ions binding the Al with polymer were identified in both the positive (AlCH3O+, AlNH+, AlNH2 +, Al2NH+) AlCNO+, AlONH3 +) and negative polarities, (AlN-, AlNO-, AlCO-, AlCNO-). Depth profiles and images near the interface were obtained. Results obtained on our model samples will be compared with laser joints obtained on “real” samples. Ultimately, this work aims at providing guidelines for improving the mechanical resistance of the weld. [less ▲]

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See detailImpact of residual transceiver impairments on MMSE filtering performance of Rayleigh-product MIMO channels
Sharma, Shree Krishna UL; Papazafeiropoulos, Anastasios; Chatzinotas, Symeon UL et al

in Proc. IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2017) (2017, July)

ecent studies have demonstrated the presence of residual transceiver hardware impairments even after employing calibration and compensation techniques in different wireless systems. The effect of these ... [more ▼]

ecent studies have demonstrated the presence of residual transceiver hardware impairments even after employing calibration and compensation techniques in different wireless systems. The effect of these impairments becomes more severe in the systems involving a large number of inexpensive Radio Frequency (RF) chains such as massive Multiple Input Multiple Output (MIMO) systems due to the requirement of cost-efficient implementation. However, most of the existing studies consider ideal transceivers without incorporating the effect of residual hardware impairments. In this regard, this paper studies the impact of additive residual transceiver hardware impairments on the Minimum Mean Square Error (MMSE) filtering performance of Rayleigh-Product (RP) MIMO channels. Using principles from Random Matrix Theory (RMT), the MMSE filtering performance of the RP channels is analyzed and a tight lower bound is derived by taking the effects of residual additive transceiver impairments into account. Moreover, some useful insights on the performance of the considered system with respect to various parameters such as the transmit Signal to Noise Ratio (SNR), the number of scatterers and the severity of impairments on both the transmit and receive sides are provided. [less ▲]

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See detailPre-Conference Workshop #3 : Experimental Media Archaeology
Fickers, Andreas UL

Presentation (2017, June 28)

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See detailCloud-Assisted Device Clustering for Lifetime Prolongation in Wireless IoT Networks
Bhandari, Sabin; Sharma, Shree Krishna UL; Wang, Xianbin

in Proc. IEEE 30th Canadian Conference on Electrical and Computer Engineering (CCECE) 2017 (2017, June 15)

One of the crucial challenges in the recently emerging Internet of Things (IoT) applications is how to handle the massive heterogeneous data generated from a large number of resource-constrained sensors ... [more ▼]

One of the crucial challenges in the recently emerging Internet of Things (IoT) applications is how to handle the massive heterogeneous data generated from a large number of resource-constrained sensors. In this context, cloud computing has emerged as a promising paradigm due to its enormous storage and computing capabilities, thus leading to the IoT-Cloud convergence. In such a framework, IoT devices can be grouped into several clusters and each cluster head can send the aggregated information to the cloud via a gateway for further processing. Although a number of clustering methods have been proposed for the conventional Wireless Sensor Networks (WSNs), it is important to consider specific IoT characteristics while adapting these techniques for wireless IoT networks. One of the important features of IoT networks that can be exploited while developing clustering techniques is the collaborations among heterogeneous IoT devices. In this regard, the network-wide knowledge at the cloud center can be useful to provide information about the device relations to the IoT gateway. Motivated by this, we propose and evaluate a cloud-assisted device interaction-aware clustering scheme for heterogeneous IoT networks. The proposed method considers the joint impact of residual energy and device closeness factor for the effective selection of cluster heads. Our results show that the proposed clustering scheme can significantly prolong the network lifetime, and enhance the overall throughput of a wireless IoT network. [less ▲]

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See detailLe panorama des auteurs italiens au Luxembourg et dans la Grande Région
Cicotti, Claudio UL

Presentation (2017, May 31)

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See detailLinear prediction of speech: The fractional derivative formula
Despotovic, Vladimir UL; Skovranek, Tomas

in Book of Abstracts, 2017 International Workshop on Fractional Calculus and Its Applications (2017, May)

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See detailJudicial Accountability in Comparative Context,
Al Hajjaji, Shams Al Din UL

Presentation (2017, April)

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See detailCall for Judicial Reform
Al Hajjaji, Shams Al Din UL

Presentation (2017, April)

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See detailLive Data Analytics with Collaborative Edge and Cloud Processing in Wireless IoT Network
Sharma, Shree Krishna UL; Wang, Xianbin

in IEEE Access (2017)

Recently, big data analytics has received important attention in a variety of application domains including business, finance, space science, healthcare, telecommunication and Internet of Things (IoT ... [more ▼]

Recently, big data analytics has received important attention in a variety of application domains including business, finance, space science, healthcare, telecommunication and Internet of Things (IoT). Among these areas, IoT is considered as an important platform in bringing people, processes, data and things/objects together in order to enhance the quality of our everyday lives. However, the key challenges are how to effectively extract useful features from the massive amount of heterogeneous data generated by resource-constrained IoT devices in order to provide real-time information and feedback to the endusers, and how to utilize this data-aware intelligence in enhancing the performance of wireless IoT networks. Although there are parallel advances in cloud computing and edge computing for addressing some issues in data analytics, they have their own benefits and limitations. The convergence of these two computing paradigms, i.e., massive virtually shared pool of computing and storage resources from the cloud and real-time data processing by edge computing, could effectively enable live data analytics in wireless IoT networks. In this regard, we propose a novel framework for coordinated processing between edge and cloud computing/processing by integrating advantages from both the platforms. The proposed framework can exploit the network-wide knowledge and historical information available at the cloud center to guide edge computing units towards satisfying various performance requirements of heterogeneous wireless IoT networks. Starting with the main features, key enablers and the challenges of big data analytics, we provide various synergies and distinctions between cloud and edge processing. More importantly, we identify and describe the potential key enablers for the proposed edge-cloud collaborative framework, the associated key challenges and some interesting future research directions. [less ▲]

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See detailRecording a Binaural Radio Drama About the History of Binaural Sound Recording
Fickers, Andreas UL

Presentation (2017, February 03)

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See detailColloque international « Questions sur l’avenir du travail de mémoire »
Fickers, Andreas UL

Presentation (2017, January 20)

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See detailAnalysis of the NORX Core Permutation
Biryukov, Alex UL; Udovenko, Aleksei UL; Velichkov, Vesselin UL

E-print/Working paper (2017)

NORX is one of the fifteen authenticated encryption algorithms that have reached the third round of the CAESAR competition. NORX is built using the sponge-based Monkey Duplex construction. In this note we ... [more ▼]

NORX is one of the fifteen authenticated encryption algorithms that have reached the third round of the CAESAR competition. NORX is built using the sponge-based Monkey Duplex construction. In this note we analyze the core permutation F. We show that it has rotational symmetries on different structure levels. This yields simple distinguishing properties for the permutation, which propagate with very high probability or even probability one. We also investigate differential symmetries in NORX at the word level. A new type of truncated differentials called symmetric truncated differentials (STD) is proposed. It is shown that, under the Markov assumption, up to 2.125 rounds of the F function of NORX32 and NORX64 can be distinguished using STD. Finally, we note that our analysis covers only the permutation F and does not immediately threaten the security claims of the designers. [less ▲]

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See detailXDEM: from HPC to the Cloud
Besseron, Xavier UL

Scientific Conference (2017, January)

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See detailMultivariate functional approximations with Stein's method of exchangeable pairs
Kasprzak, Mikolaj UL

E-print/Working paper (2017)

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See detailCriminal Liability for Environmental Damage – National Courts versus the International Tribunal for the Law of the Sea
Al Hajjaji, Shams Al Din UL

in Groningen Journal of International Law (2017)

This article argues to abolish Criminal Liability for Environmental Damage in order to consider legislative amendments, which comply with the rulings of ITLOS. There is a discrepancy between plaintiffs ... [more ▼]

This article argues to abolish Criminal Liability for Environmental Damage in order to consider legislative amendments, which comply with the rulings of ITLOS. There is a discrepancy between plaintiffs who are able to present their cases to ITLOS and those who are unable to do so. In most fishery cases, plaintiffs are unable to resort to ITLOS and national courts deal with these cases based on their own understanding, not that of ITLOS. The article differentiates between Criminal Liability for Environmental Damage (RLED) and Civil Liability for Environmental Damage (CLED). It also provides examples and explanations for the difference between them. This article is divided into four main sections. The first tackles the theoretical difference between CLED and RLED. The second section presents six cases in which the ITLOS has dealt with the question of national RLED. The cases show how ITLOS transforms RLED to CLED. The third section highlights discrepancies in the practice of both international and national courts with regard to two issues: confiscation and bond determination in fishery cases. The fourth and last part recommends a solution to overcome discrepancies between national and international courts. [less ▲]

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See detailA Call for Judicial Reform in Egypt
Al Hajjaji, Shams Al Din UL

in ICL Online Journal (2017)

The social contract in Egypt has changed dramatically five times in the past decade. Mubarak made substantial amendments in 2005 and 2007, the Supreme Council of the Armed Forces (SCAF) ratified the 2011 ... [more ▼]

The social contract in Egypt has changed dramatically five times in the past decade. Mubarak made substantial amendments in 2005 and 2007, the Supreme Council of the Armed Forces (SCAF) ratified the 2011 Constitutional Declaration, the Muslim Brotherhood adopted the 2012 Constitution and, finally, Al-Sisi/Mansur proclaimed the 2014 Constitution. Currently, Egypt faces social, economic, political and legal problems. The Egyptian judiciary plays a vital role in the inability to respond to these problems. This research argues that the call for judicial reform should be revived to face contemporary challenges. These challenges are the result of the absence of serious judicial reform in the past four decades. The 1973 Judicial Authority Law was a result of the social contract presented in the 1971 Constitution. The research lists the reasons for adopting a new judicial authority law. In the first section, the social aspect is embodied in the protection of freedoms, judicial transparency and judicial legitimacy. The second section dealing with economic reasons for reform is divided into two parts. The first deals with Independent Bodies and Regulatory Agencies. The second issue reveals the role of the judiciary in the successive failures of the IBRA. The third section deals with the role of the judiciary in political life. The fourth section presents the legal reasons for judicial reform. [less ▲]

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See detailReplacement Policy for Nuclear Energy for Peaceful Purposes: An Environmental Approach
Al Hajjaji, Shams Al Din UL

in Environmental Claims Journal (2017)

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