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See detailO-MI/O-DF vs. MQTT: a performance analysis
Benedick, Paul-Lou UL; Robert, Jérémy UL; Le Traon, Yves UL et al

in O-MI/O-DF vs. MQTT: a performance analysis (2018, June 21)

Over the past decade, a flourishing number of concepts and architectural shifts appeared such as Industrial Internet of Things (IIoT), Industrial CPS or even Industry 4.0. Unfortunately, today’s IoT as ... [more ▼]

Over the past decade, a flourishing number of concepts and architectural shifts appeared such as Industrial Internet of Things (IIoT), Industrial CPS or even Industry 4.0. Unfortunately, today’s IoT as well as Industry 4.0 environments, look more like a collection of isolated “Intranets of Things”, also referred to as “vertical silos”, rather than a federated infrastructure. Breaking down these silos is a key challenge in both the IoT and Industry 4.0 communities. This paper is intended to present and discuss two open and standardised mes- saging protocols designed for IoT applications, namely: MQTT and O-MI/O-DF. First, a traffic load’s analytical model derived from the MQTT standard specifications is presented. Second, a comparison study between MQTT and O-MI/O-DF standards is carried out based on a real-life industrial implementation. This study brings a deep understanding of the extent to which these protocols are performant (from a traffic load perspective) and how they can impact on future architectural designs. [less ▲]

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See detailHighway Network Block with Gates Constraints for Training Very Deep Networks
Oyedotun, Oyebade UL; Shabayek, Abd El Rahman UL; Aouada, Djamila UL et al

in 2018 IEEE International Conference on Computer Vision and Pattern Recognition Workshop, June 18-22, 2018 (2018, June 19)

In this paper, we propose to reformulate the learning of the highway network block to realize both early optimization and improved generalization of very deep networks while preserving the network depth ... [more ▼]

In this paper, we propose to reformulate the learning of the highway network block to realize both early optimization and improved generalization of very deep networks while preserving the network depth. Gate constraints are duly employed to improve optimization, latent representations and parameterization usage in order to efficiently learn hierarchical feature transformations which are crucial for the success of any deep network. One of the earliest very deep models with over 30 layers that was successfully trained relied on highway network blocks. Although, highway blocks suffice for alleviating optimization problem via improved information flow, we show for the first time that further in training such highway blocks may result into learning mostly untransformed features and therefore a reduction in the effective depth of the model; this could negatively impact model generalization performance. Using the proposed approach, 15-layer and 20-layer models are successfully trained with one gate and a 32-layer model using three gates. This leads to a drastic reduction of model parameters as compared to the original highway network. Extensive experiments on CIFAR-10, CIFAR-100, Fashion-MNIST and USPS datasets are performed to validate the effectiveness of the proposed approach. Particularly, we outperform the original highway network and many state-ofthe- art results. To the best our knowledge, on the Fashion-MNIST and USPS datasets, the achieved results are the best reported in literature. [less ▲]

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See detailPose Encoding for Robust Skeleton-Based Action Recognition
Demisse, Girum UL; Papadopoulos, Konstantinos UL; Aouada, Djamila UL et al

in CVPRW: Visual Understanding of Humans in Crowd Scene, Salt Lake City, Utah, June 18-22, 2018 (2018, June 18)

Some of the main challenges in skeleton-based action recognition systems are redundant and noisy pose transformations. Earlier works in skeleton-based action recognition explored different approaches for ... [more ▼]

Some of the main challenges in skeleton-based action recognition systems are redundant and noisy pose transformations. Earlier works in skeleton-based action recognition explored different approaches for filtering linear noise transformations, but neglect to address potential nonlinear transformations. In this paper, we present an unsupervised learning approach for estimating nonlinear noise transformations in pose estimates. Our approach starts by decoupling linear and nonlinear noise transformations. While the linear transformations are modelled explicitly the nonlinear transformations are learned from data. Subsequently, we use an autoencoder with L2-norm reconstruction error and show that it indeed does capture nonlinear noise transformations, and recover a denoised pose estimate which in turn improves performance significantly. We validate our approach on a publicly available dataset, NW-UCLA. [less ▲]

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See detailA Dyadic Deontic Logic in HOL
Benzmüller, Christoph UL; Farjami, Ali UL; Parent, Xavier UL

in Broersen, Jan; Condoravdi, Cleo; Nair, Shyam (Eds.) et al Deontic Logic and Normative Systems --- 14th International Conference, DEON 2018, Utrecht, The Netherlands, 3-6 July, 2018 (2018, June 11)

A shallow semantical embedding of a dyadic deontic logic by Carmo and Jones in classical higher-order logic is presented. This embedding is proven sound and complete, that is, faithful. The work presented ... [more ▼]

A shallow semantical embedding of a dyadic deontic logic by Carmo and Jones in classical higher-order logic is presented. This embedding is proven sound and complete, that is, faithful. The work presented here provides the theoretical foundation for the implementation and automation of dyadic deontic logic within off-the-shelf higher-order theorem provers and proof assistants. [less ▲]

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See detailThe influence of a thin weak soil layer on the pile bearing capacity.
Rica, Shilton UL; Van Baars, Stefan UL

in International Conference on Deep Foundations and Ground Improvement, Urbanization and Infrastructure Development: Future Challenges (2018, June 05)

Most pile design methods for estimating the pile bearing capacity, are based on data from the cone penetration tests (CPT), such as the Dutch (Koppejan) method, the Belgium (De Beer) method or the French ... [more ▼]

Most pile design methods for estimating the pile bearing capacity, are based on data from the cone penetration tests (CPT), such as the Dutch (Koppejan) method, the Belgium (De Beer) method or the French (Bustamante & Gianeselli) method. In all these methods, the unit cone resistance of the CPT has to be averaged within an influence zone around the pile tip, in order to be able to calculate the pile tip bearing capacity. The influence zone is defined as the zone in which the parameters of the soil have an influence on the pile tip bearing capacity. For the French method this zone is between 1.5 times the pile diameter, D, above and below the pile tip; while for the Dutch method this zone is between 8 D above to a maximum of 4 D below the pile tip. Numerical simulations on piles installed in homogeneous sandy soil, show that these definitions of the influence zone are not accurate. The simulations show an influence zone from 1 or 2 D above, to 5 or 6 D below the pile tip, depending on the soil parameters. In this research, also the influence of a weak thin soil layer on the pile bearing capacity has been studied. All simulations are made for two different thicknesses of the thin soil layer. Also the soil strength parameters and soil stiffness parameters have been varied, in order to show the influence of this thin soil layer. This influence zone has been confirmed by laboratory tests. [less ▲]

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See detailAugmented Reality-based human-robot Interaction Method: ARBI
Gallala, Abir UL; Hichri, Bassem UL; Plapper, Peter UL

in Robotix Academy Conference for Industrial Robotics (RACIR 2018) (2018, June)

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See detailAttitudes of Children with Autism towards Robots: An Exploratory Study
Pinto Costa, Andreia UL; Schweich, Tonie UL; Charpiot, Louise UL et al

in ACM SIGCHI IDC2018 Workshop on Children's Robotics and Child-Robot Interaction (2018, June)

In this exploratory study we assessed how attitudes of children with autism spectrum disorder (ASD) towards robots together with children’s autism-related social impairments are linked to indicators of ... [more ▼]

In this exploratory study we assessed how attitudes of children with autism spectrum disorder (ASD) towards robots together with children’s autism-related social impairments are linked to indicators of children’s preference of an interaction with a robot over an interaction with a person. We found that children with ASD have overall positive attitudes towards robots and that they often prefer interacting with a robot than with a person. Several of children’s attitudes were linked to children’s longer gazes towards a robot compared to a person. Autism-related social impairments were linked to more repetitive and stereotyped behaviors and to a shorter gaze duration in the interaction with the robot compared to the person. These preliminary results contribute to better understand factors that might help determine sub-groups of children with ASD for whom robots could be particularly useful. [less ▲]

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See detailThe bearing capacity of shallow foundations on slopes
Van Baars, Stefan UL

in Proceedings of NUMGE 2018 9th European Conference on Numerical Methods in Geotechnical Engineering (2018, June)

In 1920 Prandtl published an analytical solution for the bearing capacity of a soil under a strip load. Over the years, extensions have been made for a surrounding surcharge, the soil weight, the shape of ... [more ▼]

In 1920 Prandtl published an analytical solution for the bearing capacity of a soil under a strip load. Over the years, extensions have been made for a surrounding surcharge, the soil weight, the shape of the footing, the inclination of the load, and also for a slope. In order to check the current extensions of a loaded strip footing next to a slope, many finite element calculations have been made, showing that these extensions are often inaccurate. Therefore new factors have been proposed, which are for both the soil-weight and the surcharge slope bearing capacity, based on the numerical calculations, and for the cohesion slope bearing capacity, also on an analytical solution. [less ▲]

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See detailDutch field tests validating the bearing capacity of Fundex piles
Van Baars, Stefan UL; Rica, Shilton UL; De Nijs, G.A. et al

in Proceedings of CPT’18 – International Symposium on Cone Penetration Testing (2018, June)

In 1939, Boonstra was the first to base the tip bearing capacity of foundation piles on the CPT cone resistance. Since then, many engineers and scientists have proposed improved design methods for the ... [more ▼]

In 1939, Boonstra was the first to base the tip bearing capacity of foundation piles on the CPT cone resistance. Since then, many engineers and scientists have proposed improved design methods for the bearing capacity of foundation piles, such as the Dutch Koppejan method. This method holds a mistake in the qc-averaging method. Its tip resistance is based on the cone resistance of an assumed zone between 8D above the tip and 4D below the tip, while several researchers show that this should be in a zone between 2D above the tip and 8D below the tip. In the Netherlands, Belgium and France a field test has been performed indicating that the currently used design method in the Netherlands (the Koppejan Method) was about 30% too high for the tip resistance. This, and also the current qc-averaging method, conflict with the findings of Boonstra, Plantema, Huizinga and White & Bolton. Besides, in the field test, the residual stresses in the piles after installation were completely ignored, in fact, not even measured. Nevertheless, the Dutch Norm Commission Geo-Engineering decided to reduce the bearing capacity of foundation piles in the Netherlands, unless other field tests prove otherwise. Since this reduction is very drastic and since no serious problems due to the use of the unreduced bearing capacity were recorded, the geotechnical contracting company Funderingstechnieken Verstraeten BV has performed field tests on six Fundex piles, and asked the engineering company BMNED to assist with these tests and the design. The aim was to prove that, at least for Fundex piles, a reduction of 30% is too much. The Fundex Pile Tests in Terneuzen show that, especially for the grouted Fundex piles, the pile type factor should not be reduced in combination with the current qc-averaging method. [less ▲]

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See detailPerformance Analysis of CoAP under Satellite Link Disruption
Giotti, Domenico UL; Lamorte, Luca UL; Soua, Ridha UL et al

in Performance Analysis of CoAP under Satellite Link Disruption (2018, June)

Internet of Things (IoT) devices connectivity is steadily increasing in both heterogeneity and sophistication. However, classical and emerging technology (Wi-Fi, Zigbee, LoRa, etc.) are not able to ... [more ▼]

Internet of Things (IoT) devices connectivity is steadily increasing in both heterogeneity and sophistication. However, classical and emerging technology (Wi-Fi, Zigbee, LoRa, etc.) are not able to support well IoT applications, when terrestrial networks are no longer available (e.g., in remote not habitable areas, in the occurrence of calamities). Subsequently, the only way forward is to transmit IoT data over satellite. The integrated satellite-terrestrial networks are emerging as a promising solution to ensure ubiquitous IoT connectivity, higher throughput and reliability. Being different by design, IoT protocols’ tuning is needed to integrate terrestrial and satellite segments. In the current paper, we evaluate the performances of CoAP, the well-known lightweight application protocol for IoT in an integrated scenario, taking into account the satellite link disruption. The key findings of our study, conducted using the OpenSAND simulator, show that decreasing the value of congestion control parameters proposed by the standard [1], mainly ACK_TIMEOUT and ACK_RANDOM_FACTOR, is crucial to achieve lower end-to-end delays and higher packet delivery ratio. [less ▲]

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See detailEnergy-Efficient Data Acquisition in Mobile Crowdsensing Systems
Capponi, Andrea UL

in 19th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM), Chania, Greece, 2018 (2018, June)

Mobile Crowdsensing (MCS) is one of the most promising paradigms for monitoring phenomena in urban environments. The success of a MCS campaign relies on large participation of citizens, who may be ... [more ▼]

Mobile Crowdsensing (MCS) is one of the most promising paradigms for monitoring phenomena in urban environments. The success of a MCS campaign relies on large participation of citizens, who may be reluctant in joining a campaign due to sensing and reporting costs they sustain. Hence, it is fundamental to propose efficient data collection frameworks (DCFs). In the first stages of our work, we proposed an energyefficient DCF that aims to minimize energy consumption while maximizing the utility of contributed data. Then, we developed an Android application and proposed a methodology to compare several DCFs, performing energy- and network-related measures with Power Monitor and Wireshark. Currently, we are investigating collaborative data delivery as a more efficient solution than the individual one. The key idea is to form groups of users and elect a responsible for aggregated data delivery. To this end, it is crucial to analyze device to device (D2D) communications and propose efficient policies for group formation and owner election. To evaluate the performance in realistic urban environments we exploit CrowdSenSim, which runs large-scale simulations in citywide scenarios. [less ▲]

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See detailDevelopment of an innovative type of shear connector dedicated to fully embedded steel-concrete composite columns - experimental and numerical investigations
Chrzanowski, Maciej UL; Odenbreit, Christoph UL; Obiala, Renata et al

in Proceedings of the ASCCS 2018 Conference, Valencia, Spain, June 27-29, 2018 (2018, June)

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See detailExperience report: How to extract security protocols’ specifications from C libraries
Vazquez Sandoval, Itzel UL; Lenzini, Gabriele UL

in 2018 IEEE 42nd Annual Computer Software and Applications Conference (COMPSAC), Volume 2 (2018, June)

Often, analysts have to face a challenging situation when formally verifying the implementation of a security protocol: they need to build a model of the protocol from only poorly or not documented code ... [more ▼]

Often, analysts have to face a challenging situation when formally verifying the implementation of a security protocol: they need to build a model of the protocol from only poorly or not documented code, and with little or no help from the developers to better understand it. Security protocols implementations frequently use services provided by libraries coded in the C programming language; automatic tools for codelevel reverse engineering offer good support to comprehend the behavior of code in object-oriented languages but are ineffective to deal with libraries in C. Here we propose a systematic, yet human-dependent approach, which combines the capabilities of state-of-the-art tools in order to help the analyst to retrieve, step by step, the security protocol specifications from a library in C. Those specifications can then be used to create the formal model needed to carry out the analysis. [less ▲]

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See detailMega columns with several reinforced steel profiles - experimental and numerical investigations
Bogdan, Teodora; Chrzanowski, Maciej UL

in Proceedings of the ASCCS 2018 Conference, Valencia, Spain, June 27-29, 2018 (2018, June)

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See detailA Mathematical Model and a Firefly Algorithm for an Extended Flexible Job Shop Problem with Availability Constraints
Tessaro Lunardi, Willian UL; Cherri, Luiz Henrique; Voos, Holger UL

in 17th International Conference on Artificial Intelligence and Soft Computing, Zakopane, Poland, June 3-7, 2018 (2018, June)

Manufacturing scheduling strategies have historically ignored the availability of the machines. The more realistic the schedule, more accurate the calculations and predictions. Availability of machines ... [more ▼]

Manufacturing scheduling strategies have historically ignored the availability of the machines. The more realistic the schedule, more accurate the calculations and predictions. Availability of machines will play a crucial role in the Industry 4.0 smart factories. In this paper, a mixed integer linear programming model (MILP) and a discrete firefly algorithm (DFA) are proposed for an extended multi-objective FJSP with availability constraints (FJSP-FCR). Several standard instances of FJSP have been used to evaluate the performance of the model and the algorithm. New FJSP-FCR instances are provided. Comparisons among the proposed methods and other state-of-the-art reported algorithms are also presented. Alongside the proposed MILP model, a Genetic Algorithm is implemented for the experiments with the DFA. Extensive investigations are conducted to test the performance of the proposed model and the DFA. The comparisons between DFA and other recently published algorithms shows that it is a feasible approach for the stated problem. [less ▲]

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See detailCarrier Allocation for 5G Integrated Satellite-Terrestrial Backhaul Networks
Lagunas, Eva UL; Chatzinotas, Symeon UL; Ottersten, Björn UL

in International Conference on Communications (ICT), Saint-Malo, France, June 2018. (2018, June)

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See detailTowards trajectory planning from a given path for multirotor aerial robots trajectory tracking
Sanchez Lopez, Jose Luis UL; Olivares Mendez, Miguel Angel UL; Castillo Lopez, Manuel UL et al

in 2018 International Conference on Unmanned Aircraft Systems (ICUAS), Dallas 12-15 June 2018 (2018, June)

Planning feasible trajectories given desired collision-free paths is an essential capability of multirotor aerial robots that enables the trajectory tracking task, in contrast to path following. This ... [more ▼]

Planning feasible trajectories given desired collision-free paths is an essential capability of multirotor aerial robots that enables the trajectory tracking task, in contrast to path following. This paper presents a trajectory planner for multirotor aerial robots carefully designed considering the requirements of real applications such as aerial inspection or package delivery, unlike other research works that focus on aggressive maneuvering. Our planned trajectory is formed by a set of polynomials of two kinds, acceleration/deceleration and constant velocity. The trajectory planning is carried out by means of an optimization that minimizes the trajectory tracking time, applying some typical constraints as m-continuity or limits on velocity, acceleration and jerk, but also the maximum distance between the trajectory and the given path. Our trajectory planner has been tested in real flights with a big and heavy aerial platform such the one that would be used in a real operation. Our experiments demonstrate that the proposed trajectory planner is suitable for real applications and it is positively influencing the controller for the trajectory tracking task. [less ▲]

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See detailThe failure mechanism of pile foundations in non-cohesive soils
Van Baars, Stefan UL

in Proceedings of NUMGE 2018 9th European Conference on Numerical Methods in Geotechnical Engineering (2018, June)

In 1920 Prandtl published an analytical solution for the bearing capacity of a centric loaded strip footing on a weightless in-finite half-space, based on a so-called Prandtl-wedge failure mechanism ... [more ▼]

In 1920 Prandtl published an analytical solution for the bearing capacity of a centric loaded strip footing on a weightless in-finite half-space, based on a so-called Prandtl-wedge failure mechanism. Meyerhof and Koppejan extended the logarithmic spiral part of the Prandtl-wedge and presented this as the failure mechanism for the tip of a foundation pile in non-cohesive soils. The numerical calculations made in this article show however that the failure zone (plastic zone) below a pile tip, is far wider and deeper than the Prandtl-wedge and that there is failure both in and out of the standard x-y plane, but most of the failure is due to an out-of-plane, circumferential or cleaving failure mechanism. Therefore, this failure mechanism is differ-ent from the Prandtl-wedge failure mechanism. Around the pile tip, there are circular thin zones with no out-of-plane failure. In these thin zones, the tangential (out-of-plane) [less ▲]

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See detailPRESEnCE: A Framework for Monitoring, Modelling and Evaluating the Performance of Cloud SaaS Web Services
Ibrahim, Abdallah Ali Zainelabden Abdallah UL

in 48th Annual IEEE/IFIP Intl. Conf. on Dependable Systems and Networks Workshops (DNS'18) (2018, June)

Cloud Services Providers (CSPs) provide cloud services to the cloud customers in the pay-per-use model and use the Service Level Agreements (SLAs) to define the quality of the provided services. SLAs are ... [more ▼]

Cloud Services Providers (CSPs) provide cloud services to the cloud customers in the pay-per-use model and use the Service Level Agreements (SLAs) to define the quality of the provided services. SLAs are just a contract which characterizing the performance and quality of the CSPs’ services. Unfortunately, There is not an automatic and standard mechanism to verify and assure that delivered services satisfy the signed SLA agreement. In this context, this work aimed at developing an automatic framework called PRESENCE, to evaluate the Quality of Service (QoS) for the deployment of the Software-as-a-Service (SaaS) Web Services (WSS) offered across several CSPs. This performance evaluation will be used to verify and check on the SLA contraventions. PRESENCE aims at quantifying in a fair and by stealth way the performance and scalability of the delivered WS. By stealthiness, we refer to the capacity of evaluating a given Cloud service through multiple workload patterns that makes them indistinguishable from a regular user traffic from the provider point of view. PRESENCE introduces a definition for the set of Common performance metrics for measuring the behavior of cloud applications on top of a given CSP. This framework opens a novel perspectives for SLA contraventions assessment, monitoring, modeling the performance metrics for SaaS WSs. [less ▲]

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See detailOn Verifying and Assuring the Cloud SLA by Evaluating the Performance of SaaS Web Services Across Multi-cloud Providers
Ibrahim, Abdallah Ali Zainelabden Abdallah UL; Varrette, Sébastien UL; Bouvry, Pascal UL

in 48th Annual IEEE/IFIP Intl. Conf. on Dependable Systems and Networks Workshops (DNS'18) (2018, June)

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See detailPOSTER: WLAN Device Fingerprinting using Channel State Information (CSI)
Adamsky, Florian UL; Retunskaia, Tatiana UL; Schiffner, Stefan UL et al

in 11th ACM Conference on Security and Privacy in Wireless and Mobile Networks (ACM WiSec) (2018, June)

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See detailORBIT - Overcoming Breakdowns in Teams with Interactive Tabletops
Sunnen, Patrick UL; Arend, Béatrice UL; Maquil, Valérie

in Kay, Judy; Luckin, Rose (Eds.) Rethinking Learning in the Digital Age: Making the Learning Sciences Count, 13th International Conference of the Learning Sciences (ICLS) 2018 (2018, June)

ORBIT implements and studies a joint problem-solving activity at an interactive tabletop providing participants with the opportunity to develop their collaboration methods by jointly overcoming breakdowns ... [more ▼]

ORBIT implements and studies a joint problem-solving activity at an interactive tabletop providing participants with the opportunity to develop their collaboration methods by jointly overcoming breakdowns. The design and the research process relies on user-centered design methods and on an ethnomethodological conversation analytic framework. The project will generate scientific knowledge on participants’ collaboration methods and create a powerful collaborative learning tool. [less ▲]

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See detailAdaptive control for a lightweight robotic arm actuated by a Shape Memory Allow wire
Quintanar Guzman, Serket UL; Kannan, Somasundar UL; Voos, Holger UL et al

in 16th International Conference on New Actuators, Bremen 25-27 June 2018 (2018, June)

This paper presents the design, model and closed-loop control of a single degree-of-freedom (DOF) lightweight robotic arm actuated by a biased Shape Memory Alloy (SMA) wire. The highly non-linear dynamics ... [more ▼]

This paper presents the design, model and closed-loop control of a single degree-of-freedom (DOF) lightweight robotic arm actuated by a biased Shape Memory Alloy (SMA) wire. The highly non-linear dynamics of SMAs represent a challenge for control tasks, due to phenomena as hysteresis or parameters uncertainty. With this in mind, we propose a control capable to adapt itself to the hysteretic behavior and update its behavior to deal with the changing parameters of the material over time. An adaptive control for position regulation is presented. This control includes a set of techniques, providing a systematic way to adjust the control parameters in real time, so maintaining the stability of the system and a desired performance, while dealing with parameter and model uncertainties. The closed-loop approach is tested in experimentally showing its effectiveness to deal with the highly non-linear dynamics of the SMA wire. [less ▲]

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See detailModel Predictive Control for Aerial Collision Avoidance in Dynamic Environments
Castillo Lopez, Manuel UL; Sajadi Alamdari, Seyed Amin UL; Sanchez Lopez, Jose Luis UL et al

in 26th Mediterranean Conference on Control and Automation (MED), Zadar, Croatia, 19-22 June 2018 (2018, June)

Autonomous navigation in unknown environments populated by humans and other robots is one of the main challenges when working with mobile robots. In this paper, we present a new approach to dynamic ... [more ▼]

Autonomous navigation in unknown environments populated by humans and other robots is one of the main challenges when working with mobile robots. In this paper, we present a new approach to dynamic collision avoidance for multi-rotor unmanned aerial vehicles (UAVs). A new nonlinear model predictive control (NMPC) approach is proposed to safely navigate in a workspace populated by static and/or moving obstacles. The uniqueness of our approach lies in its ability to anticipate the dynamics of multiple obstacles, avoiding them in real-time. Exploiting active set algorithms, only the obstacles that affect to the UAV during the prediction horizon are considered at each sample time. We also improve the fluency of avoidance maneuvers by reformulating the obstacles as orientable ellipsoids, being less prone to local minima and allowing the definition of a preferred avoidance direction. Finally, we present two real-time implementations based on simulation. The former demonstrates that our approach outperforms its analog static formulation in terms of safety and efficiency. The latter shows its capability to avoid multiple dynamic obstacles. [less ▲]

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See detailKey-Skeleton Based Feedback Tool for Assisting Physical Activity
Baptista, Renato UL; Ghorbel, Enjie UL; Shabayek, Abd El Rahman UL et al

in 2018 Zooming Innovation in Consumer Electronics International Conference (ZINC), 30-31 May 2018 (2018, May 31)

This paper presents an intuitive feedback tool able to implicitly guide motion with respect to a reference movement. Such a tool is important in multiple applications requiring assisting physical ... [more ▼]

This paper presents an intuitive feedback tool able to implicitly guide motion with respect to a reference movement. Such a tool is important in multiple applications requiring assisting physical activities as in sports or rehabilitation. Our proposed approach is based on detecting key skeleton frames from a reference sequence of skeletons. The feedback is based on the 3D geometry analysis of the skeletons by taking into account the key-skeletons. Finally, the feedback is illustrated by a color-coded tool, which reflects the motion accuracy. [less ▲]

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See detailFaCoY - A Code-to-Code Search Engine
Kim, Kisub UL; Kim, Dongsun UL; Bissyande, Tegawendé François D Assise UL et al

in International Conference on Software Engineering (ICSE 2018) (2018, May 27)

Code search is an unavoidable activity in software development. Various approaches and techniques have been explored in the literature to support code search tasks. Most of these approaches focus on ... [more ▼]

Code search is an unavoidable activity in software development. Various approaches and techniques have been explored in the literature to support code search tasks. Most of these approaches focus on serving user queries provided as natural language free-form input. However, there exists a wide range of use-case scenarios where a code-to-code approach would be most beneficial. For example, research directions in code transplantation, code diversity, patch recommendation can leverage a code-to-code search engine to find essential ingredients for their techniques. In this paper, we propose FaCoY, a novel approach for statically finding code fragments which may be semantically similar to user input code. FaCoY implements a query alternation strategy: instead of directly matching code query tokens with code in the search space, FaCoY first attempts to identify other tokens which may also be relevant in implementing the functional behavior of the input code. With various experiments, we show that (1) FaCoY is more effective than online code-to-code search engines; (2) FaCoY can detect more semantic code clones (i.e., Type-4) in BigCloneBench than the state-of-theart; (3) FaCoY, while static, can detect code fragments which are indeed similar with respect to runtime execution behavior; and (4) FaCoY can be useful in code/patch recommendation. [less ▲]

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See detailA Competitive Approach for Bi-Level Co-Evolution
Kieffer, Emmanuel UL; Danoy, Grégoire UL; Bouvry, Pascal UL et al

in 2018 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW) (2018, May 25)

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See detailROADNET: Fairness- and Throughput-Enhanced Scheduling for Content Dissemination in VANETs
Di Maio, Antonio UL; Soua, Ridha UL; Palattella, Maria Rita UL et al

in ROADNET: Fairness- and Throughput-Enhanced Scheduling for Content Dissemination in VANETs (2018, May 23)

The increasing demand for bandwidth by applications in Vehicular Ad-Hoc Networks (VANETs), combined with the increasing number of their users, stresses the importance of data dissemination schemes that ... [more ▼]

The increasing demand for bandwidth by applications in Vehicular Ad-Hoc Networks (VANETs), combined with the increasing number of their users, stresses the importance of data dissemination schemes that strike a balance between network throughput and user fairness. Ensuring this balance is challenging in vehicular networks, which are characterized by a high dynamism of the network topology, volatility of intervehicular links, and heterogeneity of the exchanged content. For these reasons, we hereby introduce ROADNET, a cooperative content dissemination scheme for VANETs. Leveraging on the Software Defined Networking (SDN) paradigm, ROADNET provides a trade-off between network throughput and user fairness by exploiting the logical centralized control of SDN and the multichannel operation of the IEEE 1609.4 standard. Realistic simulation results show that our scheme outperforms prior works in terms of both throughput (≈ 36%) and fairness (≈ 6%), providing high channel load balance (σ ≈ 1%). [less ▲]

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See detailLes bourgeois de Bohême et l’impossible légitimation ? La conjuration de Prague et de Kutná Hora de février 1309
Vomacka, Eloïse UL

in Contester au Moyen Âge : de la désobéissance à la révolte (2018, May 23)

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See detailTowards Estimating and Predicting User Perception on Software Product Variants
Martinez, Jabier; Sottet, Jean-Sebastien; Garcia-Frey, Alfonso et al

in 17th International Conference on Software Reuse (ICSR) (2018, May)

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See detailIncreasing Inequality in Joint Income and Wealth Distributions in the United States, 1995 to 2013
Chauvel, Louis UL; Bar-Haim, Eyal UL; Hartung, Anne UL et al

in Conference Online Programme & Papers (2018, May)

The study of joint income and wealth distributions is important to the understanding of economic inequality. However, these are extremely skewed variables that present tails containing strategic ... [more ▼]

The study of joint income and wealth distributions is important to the understanding of economic inequality. However, these are extremely skewed variables that present tails containing strategic information that usual methods – such as percentile grouping – cannot easily underline. In this paper, we propose a new method that is able to provide a thorough examination of tails: the isograph and the logitrank. These tools entail a more detailed conception of inequality by describing inequality at different points of the distribution. Using US data 1995-2013 from the Luxembourg Wealth Study (LWS), we find first that income inequality increased significantly, in particular in the upper middle classes. Second, the wealth- to-income ratio measuring the importance of wealth relative to income, increased significantly. The association between high wealth and high incomes, fourth, increased as well. Based on our analysis, we can conclude that this increase in the association between wealth and income is not a trivial consequence of increasing inequality, but a stronger coherence of the diagonal at the top of the income and wealth distributions. [less ▲]

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See detailCharacterising Deprecated Android APIs
Li, Li; Gao, Jun UL; Bissyande, Tegawendé François D Assise UL et al

in 15th International Conference on Mining Software Repositories (MSR 2018) (2018, May)

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See detailEnergy-efficient design for latency-tolerant content delivery networks
Vu, Thang Xuan UL; Lei, Lei UL; Vuppala, Satyanarayana et al

in 2018 IEEE Wireless Communications and Networking Conference (WCNC) (2018, May)

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See detailEfficient Resource Optimization in Wireless Networks: A Deep-Learning Assisted Approach
Lei, Lei UL; You, Lei; Yuan, Di et al

in 2018 INFORMS Telecommunications Conference (2018, May)

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See detailLatency Minimization for Content Delivery Networks with Wireless Edge Caching
Vu, Thang Xuan UL; Lei, Lei UL; Vuppala, Satyanarayana et al

in 2018 IEEE International Conference on Communications (ICC) (2018, May)

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See detailA method for function integrity diagnosis and documentation: FIDD
Wichmann, Robert; Gericke, Kilian UL; Eisenbart, Boris et al

in Proceedings of the International Design Conference - DESIGN 2018 (2018, May)

This paper introduces a method to perform systematic diagnosis of function integrity. The proposed method advances the Integrated Function Modelling framework to extend its application to risk ... [more ▼]

This paper introduces a method to perform systematic diagnosis of function integrity. The proposed method advances the Integrated Function Modelling framework to extend its application to risk identification and documentation tasks. By analyzing the system model of interdisciplinary designs, this method guides the designer to explore function vulnerability by systematic decoupling of inherent design entities. Thereby it provides unique opportunities for failure mode identification in complex, interdisciplinary systems. The motivation for this method is ensuring system function integrity. [less ▲]

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See detailEight key strategies for successful stakeholder involvement in design
Manrique, Sebastián; Simons, Daria; Eisenbart, Boris et al

in Proceedings of the International Design Conference - DESIGN 2018 (2018, May)

Design professionals work often in multi-stakeholder environments. This research aims to understand how design practitioners deal with challenges resulting from stakeholder involvement in design ... [more ▼]

Design professionals work often in multi-stakeholder environments. This research aims to understand how design practitioners deal with challenges resulting from stakeholder involvement in design activities. In this exploratory study, ten interviews were conducted with design practitioners from design agencies in the Netherlands. Eight key strategies were identified that are considered for successful stakeholder involvement. The findings can help the field of DTM to develop methods and tools that fit better with the needs of design professionals. [less ▲]

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See detailHigh-Precision Design of Pedestrian Mobility for Smart City Simulators
Vitello, Piergiorgio UL; Capponi, Andrea UL; Fiandrino, Claudio UL et al

in IEEE International Conference on Communications (ICC), Kansas City, MO, USA, 2018 (2018, May)

The unprecedented growth of the population living in urban environments calls for a rational and sustainable urban development. Smart cities can fill this gap by providing the citizens with high-quality ... [more ▼]

The unprecedented growth of the population living in urban environments calls for a rational and sustainable urban development. Smart cities can fill this gap by providing the citizens with high-quality services through efficient use of Information and Communication Technology (ICT). To this end, active citizen participation with mobile crowdsensing (MCS) techniques is a becoming common practice. As MCS systems require wide participation, the development of large scale real testbeds is often not feasible and simulations are the only alternative solution. Modeling the urban environment with high precision is a key ingredient to obtain effective results. However, currently existing tools like OpenStreetMap (OSM) fail to provide sufficient levels of details. In this paper, we apply a procedure to augment the precision (AOP) of the graph describing the street network provided by OSM. Additionally, we compare different mobility models that are synthetic and based on a realistic dataset originated from a well known MCS data collection campaign (ParticipAct). For the dataset, we propose two arrival models that determine the users’ arrivals and match the experimental contact distribution. Finally, we assess the scalability of AOP for different cities, verify popular metrics for human mobility and the precision of different arrival models. [less ▲]

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See detailMargins lead to overcapacity
Jones, Darren; Eckert, Claudia; Gericke, Kilian UL

in Proceedings of the International Design Conference - DESIGN 2018 (2018, May)

This paper categorises and describes the design stages, stakeholders and decision processes of an overcapacity boiler upgrade that came about from the excessive use of design margins. Using a hospital ... [more ▼]

This paper categorises and describes the design stages, stakeholders and decision processes of an overcapacity boiler upgrade that came about from the excessive use of design margins. Using a hospital case study, the reason behind the overcapacity and excessive margins is explored using semi-structured interviews, document analysis and process modelling. Design margins arise from a lack of systemic thinking during the design and installation phases. It is likely that margins are added as a matter of habit with no real thought to their applicability, calling into question the design process. [less ▲]

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See detailTime to Clean Your Test Objectives
Marcozzi, Michaël; Bardin, Sébastien; Kosmatov, Nikolai et al

in 40th International Conference on Software Engineering, May 27 - 3 June 2018, Gothenburg, Sweden (2018, May)

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See detailAn exploratory study on the use of new design methods in design consultancies
Filippi, Anna; Suarez Madrigal, Antonio; Eisenbart, Boris et al

in Proceedings of the International Design Conference - DESIGN 2018 (2018, May)

This paper explores the uptake of design methods in design consultancies. Our results show that new methods are primarily used in the initial phases of the design process for specific problems. The main ... [more ▼]

This paper explores the uptake of design methods in design consultancies. Our results show that new methods are primarily used in the initial phases of the design process for specific problems. The main motive for doing so is to enhance creativity and understanding of the user. Many participants modify methods to fit specific needs or develop own methods. These findings highlight the need to improve the link between industry and academia in order to increase method awareness and use. Potential ways to improve this include better descriptions of methods and the be­nefits provided. [less ▲]

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See detailImproved Division Property Based Cube Attacks Exploiting Algebraic Properties of Superpoly
Wang, Qingju UL; Hao, Yonglin; Todo, Yosuke et al

in 38th Annual International Cryptology Conference (CRYPTO 2018), Santa Barbara 19-23 Aug 2018 (2018, April 29)

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See detailPAPR Minimization through Spatio-temporal Symbol-level Precoding for the Non-linear Multi-user MISO Channel
Spano, Danilo UL; Alodeh, Maha; Chatzinotas, Symeon UL et al

in 2018 International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2018) (2018, April 19)

Symbol-level precoding (SLP) is a promising technique which allows to constructively exploit the multi-user interference in the downlink of multiple antenna systems. Recently, this approach has also been ... [more ▼]

Symbol-level precoding (SLP) is a promising technique which allows to constructively exploit the multi-user interference in the downlink of multiple antenna systems. Recently, this approach has also been used in the context of non-linear systems for reducing the instantaneous power imbalances among the antennas. However, previous works have not exploited SLP to improve the dynamic properties of the waveforms in the temporal dimension, which are fundamental for non-linear systems. To fill this gap, this paper proposes a novel precoding method, referred to as spatio-temporal SLP, which minimizes the peak-to-average power ratio of the transmitted waveforms both in the spatial and in the temporal dimensions, while at the same time exploiting the constructive interference effect. Numerical results are presented to highlight the enhanced performance of the proposed scheme with respect to state of the art SLP techniques, in terms of power distribution and symbol error rate over non-linear channels. [less ▲]

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See detailDesigning Joint Precoding and Beamforming in a Multiple Gateway Multibeam Satellite System
Joroughi, Vahid; Shankar, Bhavani UL; Maleki, Sina UL et al

in IEEE WCNC 2018 (2018, April 18)

This paper aims to design joint on-ground precoding and on-board beamforming of a multiple gateway multibeam satellite system in a hybrid space-ground mode where full frequency reuse pattern is considered ... [more ▼]

This paper aims to design joint on-ground precoding and on-board beamforming of a multiple gateway multibeam satellite system in a hybrid space-ground mode where full frequency reuse pattern is considered among the beams. In such an architecture, each gateway serves a cluster of adjacent beams such that the adjacent clusters are served through a set of gateways that are located at different geographical areas. However, such a system brings in two challenges to overcome. First, the inter-beam interference is the bottleneck of the whole system and applying interference mitigation techniques becomes necessary. Second, as the data demand increases, the ground and space segments should employ extensive bandwidth resources in the feeder link accordingly. This entails embedding an extra number of gateways aiming to support a fair balance between the increasing demand and the corresponding required feeder link resources. To solve these problems, this study investigates the impact of employing a joint multiple gateway architecture and on-board beamforming scheme. It is shown that by properly designing the on-board beamforming scheme, the number of gateways can be kept affordable even if the data demand increases. Moreover, Zero Forcing (ZF) precoding technique is considered to cope with the inter-beam interference where each gateway constructs a part of block ZF precoding matrix. The conceived designs are evaluated with a close-to-real beam pattern and the latest broadband communication standard for satellite communications. [less ▲]

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See detailSupporting Set Operations in Temporal-Probabilistic Databases
Papaioannou, Katerina; Theobald, Martin UL; Böhlen, Michael

in Proceedings of the 34th IEEE International Conference on Data Engineering, ICDE 2018, Paris, France, April 16-19, 2018 (2018, April 16)

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See detailLongitudinal Shaer in Composite Beams
Zhang, Qingjie UL; Schäfer, Markus UL

in Young Engineers Colloquium Munich 2018 (2018, April 13)

Longitudinal shear has important influences on the performance of composite beams. According to Eurocode 4, with cross-section class 1 and 2 in combination with ductile shear connectors, a plastic method ... [more ▼]

Longitudinal shear has important influences on the performance of composite beams. According to Eurocode 4, with cross-section class 1 and 2 in combination with ductile shear connectors, a plastic method, considering redistribution of longitudinal shear force is allowed. The conditions therefore are full development of plastic moment resistance and sufficient slip at interface to reach the plateau of P-δ curve of the shear connectors. However, for slim-floor beams, it is to question if the above-mentioned method can be applied. To answer it, related topics still need further investigation, which is the focus of the author’s Ph.D work. This paper presents part of the first stage results on the theoretical analysis of longitudinal shear, considering the influence of plasticity of the beam. For composite beams with rigid shear connectors, non-linear shear stress distribution appears in the plastic region, which influences the shear connector arrangement. However, detailed theoretical research is still hard to be found. In this work, based on a simple beam partly in plastic zone, mathematical equations are developed to calculate the plastic zone height and longitudinal shear stress distribution. Benchmarks with ANSYS and existing tests are performed. [less ▲]

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See detailAnalysis and Comparison of Eurocodes and Chinese codes of Design
Santos Ferreira, Katia UL; Zhang, Qingjie UL; Schäfer, Markus UL

in Young Engineers Colloquium Munich 2018 (2018, April 13)

Eurocodes (EC) which were published in 2007 are one of the most advanced standards for structure design in the world. Today, Eurocodes are not only used in EU or EFTA countries, but also many other ... [more ▼]

Eurocodes (EC) which were published in 2007 are one of the most advanced standards for structure design in the world. Today, Eurocodes are not only used in EU or EFTA countries, but also many other countries use Eurocodes or align their National standards with them, which gives Eurocodes global influence. Chinese codes of practise, on the other hand, benefit from the recent fast developed construction industry and have a vast application base. In the recent years, half of the new building floor area worldwide is built in China. Thus, it is interesting to compare Eurocodes (one of the most used codes worldwide) with the Chinese codes of design (with which most buildings were recently built). [less ▲]

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See detailA parallel best-response algorithm with exact line search for nonconvex sparsity-regularized rank minimization
Yang, Yang UL; Pesavento, Marius

in Proc. 2018 IEEE International Conference on Acoustics, Speech and Signal (2018, April)

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See detailPre-shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism
Navet, Nicolas UL; Migge, Jörn; Villanueva, Josetxo et al

in Proc. WCX World Congress Experience (2018, April)

The automotive industry is swiftly moving towards Ethernet as the high-speed communication network for in-vehicle communication. There is nonetheless a need for protocols that go beyond what standard ... [more ▼]

The automotive industry is swiftly moving towards Ethernet as the high-speed communication network for in-vehicle communication. There is nonetheless a need for protocols that go beyond what standard Ethernet has to offer in order to provide additional QoS to demanding applications such as ADAS systems or audio/video streaming. The main protocols currently considered for that purpose are IEEE802.1Q, AVB with the Credit Based Shaper mechanism (IEEE802.1Qav) and TSN with its Time-Aware Shaper (IEEE802.1Qbv). AVB/CBS and TSN/TAS both provide efficient QoS mechanisms and they can be used in a combined manner, which offers many possibilities to the designer. Their use however requires dedicated hardware and software components, and clock synchronization in the case of TAS. Previous studies have also shown that the efficiency of these protocols depends much on the application at hand and the value of the configuration parameters. In this work, we explore the use of “pre-shaping” strategies under IEEE802.1Q for bursty traffic such as audio/video streams as a simple and efficient alternative to AVB/CBS and TSN/TAS. Pre-shaping means inserting on the sender side “well-chosen” pauses between successive frames of a transmission burst (e.g., as it happens when sending a camera frame), all the other characteristics of the traffic remaining unchanged. We show on an automotive case-study how the use of pre-shaping for audio/video streams leads to a drastic reduction of the communication latencies for the best-effort streams while enabling to meet the timing constraints for the rest of the traffic. We then discuss the limitations of the pre-shaping mechanism and future works needed to facilitate its adoption. [less ▲]

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See detailOptimization of weighted individual energy efficiencies in interference networks
Matthiesen, Bho; Yang, Yang UL; Jorswieck, Eduard

in Proc. IEEE Wireless Communications and Networking Conference (2018, April)

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See detailEnabling lock-free concurrent workers over temporal graphs composed of multiple time-series
Fouquet, Francois; Hartmann, Thomas UL; Mosser, Sébastien et al

in 33rd Annual ACM Symposium on Applied Computing (SAC'18) (2018, April)

Time series are commonly used to store temporal data, e.g., sensor measurements. However, when it comes to complex analytics and learning tasks, these measurements have to be combined with structural ... [more ▼]

Time series are commonly used to store temporal data, e.g., sensor measurements. However, when it comes to complex analytics and learning tasks, these measurements have to be combined with structural context data. Temporal graphs, connecting multiple time- series, have proven to be very suitable to organize such data and ultimately empower analytic algorithms. Computationally intensive tasks often need to be distributed and parallelized among different workers. For tasks that cannot be split into independent parts, several workers have to concurrently read and update these shared temporal graphs. This leads to inconsistency risks, especially in the case of frequent updates. Distributed locks can mitigate these risks but come with a very high-performance cost. In this paper, we present a lock-free approach allowing to concurrently modify temporal graphs. Our approach is based on a composition operator able to do online reconciliation of concurrent modifications of temporal graphs. We evaluate the efficiency and scalability of our approach compared to lock-based approaches. [less ▲]

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See detailVelisarios: Byzantine Fault-Tolerant Protocols Powered by Coq
Rahli, Vincent UL; Vukotic, Ivana UL; Volp, Marcus UL et al

in ESOP 2018 (2018, April)

Our increasing dependence on complex and critical information infrastructures and the emerging threat of sophisticated attacks, ask for extended efforts to ensure the correctness and security of these ... [more ▼]

Our increasing dependence on complex and critical information infrastructures and the emerging threat of sophisticated attacks, ask for extended efforts to ensure the correctness and security of these systems. Byzantine fault-tolerant state-machine replication (BFT-SMR) provides a way to harden such systems. It ensures that they maintain correctness and availability in an application-agnostic way, provided that the replication protocol is correct and at least n-f out of n replicas survive arbitrary faults. This paper presents Velisarios a logic-of-events based framework implemented in Coq, which we developed to implement and reason about BFT-SMR protocols. As a case study, we present the first machine-checked proof of a crucial safety property of an implementation of the area's reference protocol: PBFT. [less ▲]

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See detailMicro-Architectural Power Simulator for Leakage Assessment of Cryptographic Software on ARM Cortex-M3 Processors
Le Corre, Yann UL; Groszschädl, Johann UL; Dinu, Dumitru-Daniel UL

in Fan, Junfeng; Gierlichs, Benedikt (Eds.) Constructive Side-Channel Analysis and Secure Design - 9th International Workshop, COSADE 2018, Singapore, April 23-24, 2018, Proceedings (2018, April)

Masking is a common technique to protect software implementations of symmetric cryptographic algorithms against Differential Power Analysis (DPA) attacks. The development of a properly masked version of a ... [more ▼]

Masking is a common technique to protect software implementations of symmetric cryptographic algorithms against Differential Power Analysis (DPA) attacks. The development of a properly masked version of a block cipher is an incremental and time-consuming process since each iteration of the development cycle involves a costly leakage assessment. To achieve a high level of DPA resistance, the architecture-specific leakage properties of the target processor need to be taken into account. However, for most embedded processors, a detailed description of these leakage properties is lacking and often not even the HDL model of the micro-architecture is openly available. Recent research has shown that power simulators for leakage assessment can significantly speed up the development process. Unfortunately, few such simulators exist and even fewer take target-specific leakages into account. To fill this gap, we present MAPS, a micro-architectural power simulator for the M3 series of ARM Cortex processors, one of today's most widely-used embedded platforms. MAPS is fast, easy to use, and able to model the Cortex-M3 pipeline leakages, in particular the leakage introduced by the pipeline registers. The M3 leakage properties are inferred from its HDL source code, and therefore MAPS does not need a complicated and expensive profiling phase. Taking first-order masked Assembler implementations of the lightweight cipher Simon as example, we study how the pipeline leakages manifest and discuss some guidelines on how to avoid them. [less ▲]

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See detailComparative Study of Genetic and Discrete Firefly Algorithm for Combinatorial Optimization
Tessaro Lunardi, Willian UL; Voos, Holger UL

in 33rd ACM/SIGAPP Symposium On Applied Computing, Pau, France, April 9 - 13, 2018 (2018, April)

Flexible job-shop scheduling problem (FJSP) is one of the most challenging combinatorial optimization problems. FJSP is an extension of the classical job shop scheduling problem where an operation can be ... [more ▼]

Flexible job-shop scheduling problem (FJSP) is one of the most challenging combinatorial optimization problems. FJSP is an extension of the classical job shop scheduling problem where an operation can be processed by several different machines. The FJSP contains two sub-problems, namely machine assignment problem and operation sequencing problem. In this paper, we propose and compare a discrete firefly algorithm (FA) and a genetic algorithm (GA) for the multi-objective FJSP. Three minimization objectives are considered, the maximum completion time, workload of the critical machine and total workload of all machines. Five well-known instances of FJSP have been used to evaluate the performance of the proposed algorithms. Comparisons among our methods and state-of-the-art algorithms are also provided. The experimental results demonstrate that the FA and GA have achieved improvements in terms of efficiency. Solutions obtained by both algorithms are comparable to those obtained by algorithms with local search. In addition, based on our initial experiments, results show that the proposed discrete firefly algorithm is feasible, more effective and efficient than our proposed genetic algorithm for solving multi-objective FJSP. [less ▲]

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See detailEnergy efficiency in MIMO interference channels: Social optimality and max-min fairness
Yang, Yang UL; Pesavento, Marius

in Proc. 2018 IEEE International Conference on Acoustics, Speech and Signal (2018, April)

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See detailZero-Sum Partitions of PHOTON Permutations
Wang, Qingju UL; Grassi, Lorenzo; Rechberger, Christian

in Smart, Nigel P. (Ed.) Topics in Cryptology - CT-RSA 2018 - The Cryptographers' Track at the RSA Conference 2018, San Francisco, CA, USA, April 16-20, 2018 Proceedings (2018, April)

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See detailOn Composability of Game-based Password Authenticated Key Exchange
Skrobot, Marjan UL; Lancrenon, Jean UL

in Skrobot, Marjan; Lancrenon, Jean (Eds.) 2018 IEEE European Symposium on Security and Privacy (EuroS&P) (2018, April)

It is standard practice that the secret key derived from an execution of a Password Authenticated Key Exchange (PAKE) protocol is used to authenticate and encrypt some data payload using a Symmetric Key ... [more ▼]

It is standard practice that the secret key derived from an execution of a Password Authenticated Key Exchange (PAKE) protocol is used to authenticate and encrypt some data payload using a Symmetric Key Protocol (SKP). Unfortunately, most PAKEs of practical interest are studied using so-called game-based models, which – unlike simulation models – do not guarantee secure composition per se. However, Brzuska et al. (CCS 2011) have shown that middle ground is possible in the case of authenticated key exchange that relies on Public- Key Infrastructure (PKI): the game-based models do provide secure composition guarantees when the class of higher-level applications is restricted to SKPs. The question that we pose in this paper is whether or not a similar result can be exhibited for PAKE. Our work answers this question positively. More specifically, we show that PAKE protocols secure according to the game-based Real-or-Random (RoR) definition with the weak forward secrecy of Abdalla et al. (S&P 2015) allow for safe composition with arbitrary, higher-level SKPs. Since there is evidence that most PAKEs secure in the Find-then-Guess (FtG) model are in fact secure according to RoR definition, we can conclude that nearly all provably secure PAKEs enjoy a certain degree of composition, one that at least covers the case of implementing secure channels. [less ▲]

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See detailMicro-architectural Power Simulator for Leakage Assessment of Cryptographic Software on ARM Cortex-M3 Processors
Le Corre, Yann UL; Groszschädl, Johann UL; Dinu, Dumitru-Daniel UL

in Fan, Junfeng; Gierlichs, Benedikt (Eds.) Constructive Side-Channel Analysis and Secure Design - 9th International Workshop, COSADE 2018, Singapore, April 23-24, 2018, Proceedings (2018, April)

Masking is a common technique to protect software implementations of symmetric cryptographic algorithms against Differential Power Analysis (DPA) attacks. The development of a properly masked version of a ... [more ▼]

Masking is a common technique to protect software implementations of symmetric cryptographic algorithms against Differential Power Analysis (DPA) attacks. The development of a properly masked version of a block cipher is an incremental and time-consuming process since each iteration of the development cycle involves a costly leakage assessment. To achieve a high level of DPA resistance, the architecture-specific leakage properties of the target processor need to be taken into account. However, for most embedded processors, a detailed description of these leakage properties is lacking and often not even the HDL model of the micro-architecture is openly available. Recent research has shown that power simulators for leakage assessment can significantly speed up the development process. Unfortunately, few such simulators exist and even fewer take target-specific leakages into account. To fill this gap, we present MAPS, a micro-architectural power simulator for the M3 series of ARM Cortex processors, one of today’s most widely-used embedded platforms. MAPS is fast, easy to use, and able to model the Cortex-M3 pipeline leakages, in particular the leakage introduced by the pipeline registers. The M3 leakage properties are inferred from its HDL source code, and therefore MAPS does not need a complicated and expensive profiling phase. Taking first-order masked Assembler implementations of the lightweight cipher Simon as example, we study how the pipeline leakages manifest and discuss some guidelines on how to avoid them. [less ▲]

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See detailA New Modelling Framework over Temporal Graphs for Collaborative Mobility Recommendation Systems
Toader, Bogdan UL; Moawad, Assaad UL; Fouquet, François UL et al

in A New Modelling Framework over Temporal Graphs for Collaborative Mobility Recommendation Systems (2018, March 15)

Over the years, collaborative mobility proved to be an important but challenging component of the smart cities paradigm. One of the biggest challenges in the smart mobility domain is the use of data ... [more ▼]

Over the years, collaborative mobility proved to be an important but challenging component of the smart cities paradigm. One of the biggest challenges in the smart mobility domain is the use of data science as an enabler for the implementation of large scale transportation sharing solutions. In particular, the next generation of Intelligent Transportation Systems (ITS) requires the combination of artificial intelligence and discrete simulations when exploring the effects of whatif decisions in complex scenarios with millions of users. In this paper, we address this challenge by presenting an innovative data modelling framework that can be used for ITS related problems. We demonstrate that the use of graphs and time series in multi-dimensional data models can satisfy the requirements of descriptive and predictive analytics in real-world case studies with massive amounts of continuously changing data. The features of the framework are explained in a case study of a complex collaborative mobility system that combines carpooling, carsharing and shared parking. The performance of the framework is tested with a large-scale dataset, performing machine learning tasks and interactive realtime data visualization. The outcome is a fast, efficient and complete architecture that can be easily deployed, tested and used for research as well in an industrial environment. [less ▲]

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See detailMensch-Roboter-Kollaboration für Demontageprozesse
Groß, Sebastian UL; Gerke, Wolfgang; Plapper, Peter UL

in Smajic, Hasan (Ed.) AALE 2018 Das Forum für Fachleute der Automatisierungstechnik aus Hochschulen und Wirtscha 15. Fachkonferenz (2018, March 02)

Die Refabrikation gebrauchter Bauteile erlaubt eine erhebliche Einsparung von Rohstoffen, Energie und Kosten. Der hohe Anteil an manueller Arbeit im Refabrikationsschritt Demontage verringert allerdings ... [more ▼]

Die Refabrikation gebrauchter Bauteile erlaubt eine erhebliche Einsparung von Rohstoffen, Energie und Kosten. Der hohe Anteil an manueller Arbeit im Refabrikationsschritt Demontage verringert allerdings die Wirtschaftlichkeit. Dadurch wird die Implementierung der Refabrikati-on im industriellen Umfeld oftmals verhindert. Die Vollautomatisierung des Demontagepro-zesses ist aufgrund der Komplexität und der damit verbundenen Kosten, in vielen Fällen nicht umsetzbar. Hier bietet die Zusammenarbeit zwischen Mensch und Roboter einen vielverspre-chenden Ansatz zur Erhöhung der Prozesseffizienz. Bei einer Zusammenarbeit zwischen Mensch und Roboter spielt deren Interaktion und Kommunikation eine zentrale Rolle. In dieser Arbeit wird deshalb vorgestellt, welche Interaktionsrollen der Mensch in einem Demon-tageprozess einnehmen kann, welche Kommunikationskanäle sich zur Informationsübertra-gung eignen und wie diese in einer Demontageapplikation umgesetzt werden können. Bei dieser Applikation wird die Demontage einer Zusatzkühlmittelpumpe aus dem Automobilbe-reich, mit Hilfe einer agentenbasierten Steuerung vorgestellt. Dazu wurden einige neue Interaktionsformen Mensch-Roboter entwickelt, die den geplanten kollaborativen Einsatz erleichtern sollen. [less ▲]

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See detailNon-intrusive Distracted Driving Detection Based on Driving Sensing Data
Jafarnejad, Sasan UL; Castignani, German UL; Engel, Thomas UL

in 4th International Conference on Vehicle Technology and Intelligent Transport Systems (VEHITS 2018) (2018, March)

Nowadays Internet-enabled phones have become ubiquitous, and we all witness the flood of information that often arrives with a notification. Most of us immediately divert our attention to our phones even ... [more ▼]

Nowadays Internet-enabled phones have become ubiquitous, and we all witness the flood of information that often arrives with a notification. Most of us immediately divert our attention to our phones even when we are behind the wheel. Statistics show that drivers use their phone on 88% of their trips and on 2015 in the UnitedKingdom 25% of the fatal accidents were caused by distraction or impairment. Therefore there is need to tackle this issue. However, most of the distraction detection methods either use expensive dedicated hardware and/or they make use of intrusive or uncomfortable sensors. We propose distracted driving detection mechanism using non-intrusive vehicle sensor data. In the proposed method 9 driving signals are used. The data is collected, then two sets of statistical and cepstral features are extracted using a sliding window process, further a classifier makes a prediction for each window frame, lastly, a decision function takes the last l predictions and makes the final prediction. We evaluate the subject independent performance of the proposed mechanism using a driving dataset consisting of 13 drivers. We show that performance increases as the decision window become larger.We achieve the best results using a Gradient Boosting classifier with a decision window of total duration 285seconds which yield ROC AUC of 98.7%. [less ▲]

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See detailExtracting Statistical Graph Features for Accurate and Efficient Time Series Classification
Li, Daoyuan UL; Lin, Jessica; Bissyande, Tegawendé François D Assise UL et al

in 21st International Conference on Extending Database Technology (2018, March)

This paper presents a multiscale visibility graph representation for time series as well as feature extraction methods for time series classification (TSC). Unlike traditional TSC approaches that seek to ... [more ▼]

This paper presents a multiscale visibility graph representation for time series as well as feature extraction methods for time series classification (TSC). Unlike traditional TSC approaches that seek to find global similarities in time series databases (eg., Nearest Neighbor with Dynamic Time Warping distance) or methods specializing in locating local patterns/subsequences (eg., shapelets), we extract solely statistical features from graphs that are generated from time series. Specifically, we augment time series by means of their multiscale approximations, which are further transformed into a set of visibility graphs. After extracting probability distributions of small motifs, density, assortativity, etc., these features are used for building highly accurate classification models using generic classifiers (eg., Support Vector Machine and eXtreme Gradient Boosting). Thanks to the way how we transform time series into graphs and extract features from them, we are able to capture both global and local features from time series. Based on extensive experiments on a large number of open datasets and comparison with five state-of-the-art TSC algorithms, our approach is shown to be both accurate and efficient: it is more accurate than Learning Shapelets and at the same time faster than Fast Shapelets. [less ▲]

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See detailProfiling Energy Efficiency of Mobile Crowdsensing Data Collection Frameworks for Smart City Applications
Tomasoni, Mattia; Capponi, Andrea UL; Fiandrino, Claudio UL et al

in The 6th IEEE International Conference on Mobile Cloud Computing, Services, and Engineering (IEEE Mobile Cloud 2018) (2018, March)

Mobile crowdsensing (MCS) has emerged in the last years and has become one of the most prominent paradigms for urban sensing. In MCS, citizens actively participate in the sensing process by contributing ... [more ▼]

Mobile crowdsensing (MCS) has emerged in the last years and has become one of the most prominent paradigms for urban sensing. In MCS, citizens actively participate in the sensing process by contributing data with their smartphones, tablets, wearables and other mobile devices to a collector. As citizens sustain costs while contributing data, i.e., the energy spent from the batteries for sensing and reporting, devising energy efficient data collection frameworks (DCFs) is essential. In this work, we compare the energy efficiency of several DCFs through CrowdSenSim, which allows to perform large-scale simulation experiments in realistic urban environments. Specifically, the DCFs under analysis differ one with each other by the data reporting mechanism implemented and the signaling between users and the collector needed for sensing and reporting decisions. Results reveal that the key criterion differentiating DCFs' energy consumption is the data reporting mechanism. In principle, continuous reporting to the collector should be more energy consuming than probabilistic reporting. However, DCFs with continuous reporting that implement mechanisms to block sensing and data delivery after a certain amount of contribution are more effective in harvesting data from the crowd. [less ▲]

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See detailRetrouver le rapport à l’histoire et à l’Europe
Poirier, Philippe UL; Hartog, François

in Herzog, Philippe (Ed.) Europe 21 (2018, February 28)

L’Europe n’a de sens et de fondement que si les gens peuvent acquérir une conscience commune, former des projets communs, générer un affectio societatis. Ce n’est pas le cas aujourd’hui. Nous voulons donc ... [more ▼]

L’Europe n’a de sens et de fondement que si les gens peuvent acquérir une conscience commune, former des projets communs, générer un affectio societatis. Ce n’est pas le cas aujourd’hui. Nous voulons donc mettre la culture au cœur de l’espace public européen, au cœur de chaque action, et pour cela faire appel à toutes les sources d’inspiration en conjuguant foi et raison. La formation d’acteurs de la société civile capables de mettre les populations en relation et de porter des projets par-delà les frontières est essentielle. Ceci exige de dépasser les barrières nationales, psychiques et institutionnelles, et implique une culture de l’altérité afin que l’Europe puisse répondre positivement aux défis internes et externes de la mondialisation [less ▲]

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See detailIMPROVING THE CAPACITY OF VERY DEEP NETWORKS WITH MAXOUT UNITS
Oyedotun, Oyebade UL; Shabayek, Abd El Rahman UL; Aouada, Djamila UL et al

in 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (2018, February 21)

Deep neural networks inherently have large representational power for approximating complex target functions. However, models based on rectified linear units can suffer reduction in representation ... [more ▼]

Deep neural networks inherently have large representational power for approximating complex target functions. However, models based on rectified linear units can suffer reduction in representation capacity due to dead units. Moreover, approximating very deep networks trained with dropout at test time can be more inexact due to the several layers of non-linearities. To address the aforementioned problems, we propose to learn the activation functions of hidden units for very deep networks via maxout. However, maxout units increase the model parameters, and therefore model may suffer from overfitting; we alleviate this problem by employing elastic net regularization. In this paper, we propose very deep networks with maxout units and elastic net regularization and show that the features learned are quite linearly separable. We perform extensive experiments and reach state-of-the-art results on the USPS and MNIST datasets. Particularly, we reach an error rate of 2.19% on the USPS dataset, surpassing the human performance error rate of 2.5% and all previously reported results, including those that employed training data augmentation. On the MNIST dataset, we reach an error rate of 0.36% which is competitive with the state-of-the-art results. [less ▲]

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See detailDiluting the Scalability Boundaries: Exploring the Use of Disaggregated Architectures for High-Level Network Data Analysis
Vega Moreno, Carlos Gonzalo UL; Zazo, José Fernando; Meyer, Hugo et al

in Vega Moreno, Carlos Gonzalo (Ed.) 2017 IEEE 19th International Conference on High Performance Computing and Communications; IEEE 15th International Conference on Smart City; IEEE 3rd International Conference on Data Science and Systems (HPCC/SmartCity/DSS) (2018, February 15)

Traditional data centers are designed with a rigid architecture of fit-for-purpose servers that provision resources beyond the average workload in order to deal with occasional peaks of data ... [more ▼]

Traditional data centers are designed with a rigid architecture of fit-for-purpose servers that provision resources beyond the average workload in order to deal with occasional peaks of data. Heterogeneous data centers are pushing towards more cost-efficient architectures with better resource provisioning. In this paper we study the feasibility of using disaggregated architectures for intensive data applications, in contrast to the monolithic approach of server-oriented architectures. Particularly, we have tested a proactive network analysis system in which the workload demands are highly variable. In the context of the dReDBox disaggregated architecture, the results show that the overhead caused by using remote memory resources is significant, between 66% and 80%, but we have also observed that the memory usage is one order of magnitude higher for the stress case with respect to average workloads. Therefore, dimensioning memory for the worst case in conventional systems will result in a notable waste of resources. Finally, we found that, for the selected use case, parallelism is limited by memory. Therefore, using a disaggregated architecture will allow for increased parallelism, which, at the same time, will mitigate the overhead caused by remote memory. [less ▲]

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See detailCooperative sensing delay minimization in cloud-assisted DSA networks
Sharma, Shree Krishna UL; Wang, Xianbin

in Proc. IEEE PIMRC 2017 (2018, February 15)

Dynamic Spectrum Access (DSA) is considered as a promising solution to address the problem of spectrum scarcity in future wireless networks. However, the main challenges associated with this approach are ... [more ▼]

Dynamic Spectrum Access (DSA) is considered as a promising solution to address the problem of spectrum scarcity in future wireless networks. However, the main challenges associated with this approach are to acquire accurate spectrum usage information in a timely manner and to deal with the dynamicity of channel occupancy. Although Cooperative Sensing (CS) can provide significant advantages over individual device-level sensing in terms of sensing efficiency and the achievable throughput, the acquired channel occupancy information may become outdated in dynamic channel conditions due to the involved latency. In this regard, we propose to utilize a collaborative cloud-edge processing framework to minimize the CS delay in DSA networks. In this framework, the cloud-center can estimate channel occupancy parameters such as duty cycle based on the available historical sensing data by using a suitable spectrum prediction technique, and subsequently this prior knowledge can be utilized to adapt the sensing mechanism employed at the edge-side of a DSA network. Motivated by this, we formulate and solve the problem of minimizing CS delay in cloud-assisted DSA networks. A two-stage bisection search method is employed to solve this CS delay minimization problem. Our results show that the proposed cloud-assisted CS scheme can significantly reduce the CS delay in DSA networks. [less ▲]

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See detailInsights on the Performance and Configuration of AVB and TSN in Automotive Ethernet Networks
Migge, Jörn; Villanueva, Josetxo; Navet, Nicolas UL et al

in Proc. Embedded Real-Time Software and Systems (ERTS 2018) (2018, February 02)

Switched Ethernet is profoundly reshaping in-car communications. To meet the diverse real-time requirements in automotive communications, Quality-of-Service protocols that go beyond the mere use of ... [more ▼]

Switched Ethernet is profoundly reshaping in-car communications. To meet the diverse real-time requirements in automotive communications, Quality-of-Service protocols that go beyond the mere use of priorities are required. In this work, the basic questions that we investigate on a case-study with diverse and demanding communication requirements is what can we expect from the various protocols aimed at providing a better timing Quality of Service on top of Ethernet? And how to use them? Especially how to use them in a combined manner. We will focus on the Credit-Based Shaper of AVB, the Time-Aware Shaper of TSN and the use of priorities as defined in IEEE802.1Q. The performance metrics considered are the distributions of the communication latencies, obtained by simulation, as well as upper bounds on these quantities obtained by worst-case schedulability analysis. If there have been over the last 5 years numerous studies on the performance of AVB CBS, the literature on comparing AVB to TSN and other candidate protocols is still sparse. To the best of our knowledge, this empirical study is the first to consider most protocols currently considered in the automotive domain, with the aim to gain insights into the different technological, design and configurations alternatives. In particular, an objective of this study is to identify key problems that need to be solved in order to further automate network design and configuration. [less ▲]

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See detailSimulation-Based Fault Injection as a Verification Oracle for the Engineering of Time-Triggered Ethernet networks
Fejoz, Loïc; Regnier, Bruno; Miramont, Philippe et al

in Proc. Embedded Real-Time Software and Systems (ERTS 2018) (2018, February 02)

TTEthernet (TTE) is considered for use as high-speed backbone in the avionics of next-generation orbital space launchers. Given the key role of communication in launchers, the OEM must acquire a precise ... [more ▼]

TTEthernet (TTE) is considered for use as high-speed backbone in the avionics of next-generation orbital space launchers. Given the key role of communication in launchers, the OEM must acquire a precise understanding of TTE’s functioning and its performances in nominal and error conditions. This holds especially true for the clock synchronization algorithm, the cornerstone of time-triggered communication in TTE, which involves complex distributed algorithms. In this study, we use both an experimental platform and fault-injection on a simulation model to gain quantified insights in these questions. We first describe a fine-grained simulation model of TTE model and discuss how it has been validated against communication traces recorded on the TTE platform. We then present experiments that evaluate the accuracy of the clock synchronization in TTE in the fault-free case as well as considering permanent link failure and transient transmission errors. Finally, we discuss what we have learned during the project in terms of development process and programming language support for complex simulation models used in the design of critical systems. [less ▲]

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See detailOptimal First-Order Boolean Masking for Embedded IoT Devices
Biryukov, Alex UL; Dinu, Dumitru-Daniel UL; Le Corre, Yann UL et al

in CARDIS 2017: Smart Card Research and Advanced Applications (2018, January 26)

Boolean masking is an effective side-channel countermeasure that consists in splitting each sensitive variable into two or more shares which are carefully manipulated to avoid leakage of the sensitive ... [more ▼]

Boolean masking is an effective side-channel countermeasure that consists in splitting each sensitive variable into two or more shares which are carefully manipulated to avoid leakage of the sensitive variable. The best known expressions for Boolean masking of bitwise operations are relatively compact, but even a small improvement of these expressions can significantly reduce the performance penalty of more complex masked operations such as modular addition on Boolean shares or of masked ciphers. In this paper, we present and evaluate new secure expressions for performing bitwise operations on Boolean shares. To this end, we describe an algorithm for efficient search of expressions that have an optimal cost in number of elementary operations. We show that bitwise AND and OR on Boolean shares can be performed using less instructions than the best known expressions. More importantly, our expressions do no require additional random values as the best known expressions do. We apply our new expressions to the masked addition/subtraction on Boolean shares based on the Kogge-Stone adder and we report an improvement of the execution time between 14% and 19%. Then, we compare the efficiency of first-order masked implementations of three lightweight block ciphers on an ARM Cortex-M3 to determine which design strategies are most suitable for efficient masking. All our masked implementations passed the t-test evaluation and thus are deemed secure against first-order side-channel attacks. [less ▲]

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See detailBesoins des apprenants en matière de pensée algébrique et connaissances pour enseigner cette pensée : évaluation diagnostique des acquis des enseignants à la transition école-collège
Demonty, Isabelle; Vlassis, Joëlle UL; Fagnant, Annick

in Demeuse, Marc; Milmeister, Marianne; Weis, Christiane (Eds.) L'évaluation en éducation et en formation face aux transformations des sociétés contemporaines. Actes du 30e colloque de l'Admée-Europe (2018, January)

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See detailDéveloppement d’un test de compétences numériques précoces destiné à mesurer les effets d’une intervention mise en place auprès d’élèves de 4 à 6 ans
de Chambrier, Anne-Françoise; Vlassis, Joëlle UL; Fagnant, Annick et al

in Demeuse, Marc; Milmeister, Marianne; Weis, Christiane (Eds.) L'évaluation en éducation et en formation face aux transformations des sociétés contemporaines. Actes du 30e colloque de l'Admée-Europe (2018, January)

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See detailPRESENCE: Toward a Novel Approach for Performance Evaluation of Mobile Cloud SaaS Web Services
Ibrahim, Abdallah Ali Zainelabden Abdallah UL; Varrette, Sébastien UL; Bouvry, Pascal UL

in Proc. of the 32nd IEEE Intl. Conf. on Information Networking (ICOIN 2018) (2018, January)

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See detailLatency Minimization in Wireless IoT Using Prioritized Channel Access and Data Aggregation
Bhandari, Sabin; Sharma, Shree Krishna UL; Wang, Xianbin

in Proc. IEEE Global Communications (GLOBECOM) Conf. 2018 (2018, January)

Future Internet of Things (IoT) networks are expected to support a massive number of heterogeneous devices/sensors in diverse applications ranging from eHealthcare to industrial control systems. In highly ... [more ▼]

Future Internet of Things (IoT) networks are expected to support a massive number of heterogeneous devices/sensors in diverse applications ranging from eHealthcare to industrial control systems. In highly-dense deployment scenarios such as industrial IoT systems, providing reliable communication links with low-latency becomes challenging due to the involved system delay including data acquisition and processing latencies at the edge-side of IoT networks. In this regard, this paper proposes a priority-based channel access and data aggregation scheme at the Cluster Head (CH) to reduce channel access and queuing delays in a clustered industrial IoT network. First, a prioritized channel access mechanism is developed by assigning different Medium Access Control (MAC) layer attributes to the packets coming from two types of IoT nodes, namely, high-priority and low-priority nodes, based on the application-specific information provided from the cloud-center. Subsequently, a preemptive M/G/1 queuing model is employed by using separate low-priority and high- priority queues before sending aggregated data to the Cloud. Our results show that the proposed priority-based method significantly improves the system latency and reliability as compared to the non-prioritized scheme. [less ▲]

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See detailPERSEUS: A Personalization Framework for Sentiment Categorization with Recurrent Neural Network
Guo, Siwen UL; Höhn, Sviatlana; Xu, Feiyu et al

in International Conference on Agents and Artificial Intelligence , Funchal 16-18 January 2018 (2018, January)

This paper introduces the personalization framework PERSEUS in order to investigate the impact of individuality in sentiment categorization by looking into the past. The existence of diversity between ... [more ▼]

This paper introduces the personalization framework PERSEUS in order to investigate the impact of individuality in sentiment categorization by looking into the past. The existence of diversity between individuals and certain consistency in each individual is the cornerstone of the framework. We focus on relations between documents for user-sensitive predictions. Individual’s lexical choices act as indicators for individuality, thus we use a concept-based system which utilizes neural networks to embed concepts and associated topics in text. Furthermore, a recurrent neural network is used to memorize the history of user’s opinions, to discover user-topic dependence, and to detect implicit relations between users. PERSEUS also offers a solution for data sparsity. At the first stage, we show the benefit of inquiring a user-specified system. Improvements in performance experimented on a combined Twitter dataset are shown over generalized models. PERSEUS can be used in addition to such generalized systems to enhance the understanding of user’s opinions. [less ▲]

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See detailMesurer les croyances des enseignants du préscolaire à propos des mathématiques
Vlassis, Joëlle UL; Dierendonck, Christophe UL; Tinnes, Mélanie UL et al

in Demeuse, Marc; Milmeister, Marianne; Weis, Christiane (Eds.) L'évaluation en éducation et en formation face aux transformations des sociétés contemporaines. Actes du 30e colloque de l'Admée-Europe (2018, January)

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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; Hilger, Jean

in Charlier, Jeremy; State, Radu; Hilger, Jean (Eds.) 2018 IEEE International Conference on Big Data and Smart Computing Proceedings (2018, January)

Smart contracts are programs stored and executed on a blockchain. The Ethereum platform, an open source blockchain-based platform, has been designed to use these programs offering secured protocols and ... [more ▼]

Smart contracts are programs stored and executed on a blockchain. The Ethereum platform, an open source blockchain-based platform, has been designed to use these programs offering secured protocols and transaction costs reduction. The Ethereum Virtual Machine performs smart contracts runs, where the execution of each contract is limited to the amount of gas required to execute the operations described in the code. Each gas unit must be paid using Ether, the crypto-currency of the platform. Due to smart contracts interactions evolving over time, analyzing the behavior of smart contracts is very challenging. We address this challenge in our paper. We develop for this purpose an innovative approach based on the nonnegative tensor decomposition PARATUCK2 combined with long short-term memory (LSTM) to assess if predictive analysis can forecast smart contracts interactions over time. To validate our methodology, we report results for two use cases. The main use case is related to analyzing smart contracts and allows shedding some light into the complex interactions among smart contracts. In order to show the generality of our method on other use cases, we also report its performance on video on demand recommendation. [less ▲]

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See detailNew Directions in Attack Tree Research: Catching up with Industrial Needs
Gadyatskaya, Olga UL; Trujillo Rasua, Rolando UL

in Mauw, Sjouke (Ed.) Proceedings of the 4th International Workshop on Graphical Models for Security (2018, January)

Attack trees provide a systematic way of characterizing diverse system threats. Their strengths arise from the combination of an intuitive representation of possible attacks and availability of formal ... [more ▼]

Attack trees provide a systematic way of characterizing diverse system threats. Their strengths arise from the combination of an intuitive representation of possible attacks and availability of formal mathematical frameworks for analyzing them in a qualitative or a quantitative manner. Indeed, the mathematical frameworks have become a large focus of attack tree research. However, practical applications of attack trees in industry largely remain a tedious and error-prone exercise. Recent research directions in attack trees, such as attack tree generation, attempt to close this gap and to improve the attack tree state-of-thepractice. In this position paper we outline the recurrent challenges in manual tree design within industry, and we overview the recent research results in attack trees that help the practitioners. For the challenges that have not yet been addressed by the community, we propose new promising research directions. [less ▲]

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See detailAnticipating Suspicious Actions using a Small Dataset of Action Templates
Baptista, Renato UL; Antunes, Michel; Aouada, Djamila UL et al

in 13th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISAPP) (2018, January)

In this paper, we propose to detect an action as soon as possible and ideally before it is fully completed. The objective is to support the monitoring of surveillance videos for preventing criminal or ... [more ▼]

In this paper, we propose to detect an action as soon as possible and ideally before it is fully completed. The objective is to support the monitoring of surveillance videos for preventing criminal or terrorist attacks. For such a scenario, it is of importance to have not only high detection and recognition rates but also low time latency for the detection. Our solution consists in an adaptive sliding window approach in an online manner, which efficiently rejects irrelevant data. Furthermore, we exploit both spatial and temporal information by constructing feature vectors based on temporal blocks. For an added efficiency, only partial template actions are considered for the detection. The relationship between the template size and latency is experimentally evaluated. We show promising preliminary experimental results using Motion Capture data with a skeleton representation of the human body. [less ▲]

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See detailThe Higher-Order Prover Leo-III
Steen, Alexander UL; Benzmüller, Christoph UL

in Automated Reasoning 9th International Joint Conference, IJCAR 2018, Held as Part of the Federated Logic Conference, FloC 2018, Oxford, UK, July 14-17, 2018, Proceedings (2018)

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See detailMind the Gap: Gender and Computer Science Conferences
van Herck, Sytze UL; Fiscarelli, Antonio Maria UL

in Kreps, David; Ess, Charles; Leenen, Louise (Eds.) et al This Changes Everything - ICT and Climate Change: What Can We Do? 13th IFIP TC 9 International Conference on Human Choice and Computers, HCC13 2018. Held at the 24th IFIP World Computer Congress, WCC2018, Poznan, Poland, September 19-21, 2018, Proceedings. (2018)

Computer science research areas are often arbitrarily defined by researchers themselves based on their own opinions or on conference rankings. First, we aim to classify conferences in computer science in ... [more ▼]

Computer science research areas are often arbitrarily defined by researchers themselves based on their own opinions or on conference rankings. First, we aim to classify conferences in computer science in an automated and objective way based on topic modelling. We then study the topic relatedness of research areas to identify isolated disciplinary silos and clusters that display more interdisciplinarity and collaboration. Furthermore, we compare career length, publication growth rate and collaboration patterns for men and women in these research areas. [less ▲]

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See detailCan Computers Help to Sharpen our Understanding of Ontological Arguments?
Benzmüller, Christoph UL; Fuenmayor, David

in Mathematics and Reality, Proceedings of the 11th All India Students' Conference on Science Spiritual Quest, 6-7 October, 2018, IIT Bhubaneswar, Bhubaneswar, India (2018)

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See detailUne cour constitutionnelle différente des autres. Etendue, raisons & avenir de l'originalité de la Cour constitutionnelle luxembourgeoise
Heuschling, Luc UL

in Gerkrath, Jörg (Ed.) Les 20 ans de la Cour Constitutionnelle: trop jeune pour mourir? (2018)

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See detailÉvaluation du potentiel cognitif sur tablette tactile : L’exemple du « TCP »
Muller, Claire UL; Reichel, Yanica UL; Martin, Romain UL

in Demeuse, Marc; Milmeister, Marianne; Weis, Christiane (Eds.) L’évaluation en éducation et en formation face aux transformations des sociétés contemporaines. Actes du colloque. (2018)

Les tablettes tactiles offrent une toute nouvelle gamme de possibilités dans le domaine de l’éducation. L’intuitivité de cet outil inspire des approches innovatrices pour l’évaluation de compétences, qui ... [more ▼]

Les tablettes tactiles offrent une toute nouvelle gamme de possibilités dans le domaine de l’éducation. L’intuitivité de cet outil inspire des approches innovatrices pour l’évaluation de compétences, qui sont mieux adaptées aux besoins spécifiques des étudiants que les tests conventionnels. Dans la présente communication nous présenterons le « Test of cognitive potential » (TCP), un test de raisonnement développé au sein du Luxembourg Centre for Educational Testing (LUCET). Avec ses instructions non verbales, présentées par vidéo, ce test donne la possibilité de mesurer le raisonnement logique indépendamment de toute langue, ce qui pourra contribuer à une réduction d’inégalités dans le système scolaire. Le TCP répond donc à une demande très concrète du terrain. Dans un contexte langagier complexe, comme celui du Luxembourg, la distinction entre troubles de l’apprentissage et simples retards dans la compréhension de la langue d’instruction est cruciale pour trouver le soutien scolaire optimal pour chaque élève. Pour cela, le potentiel cognitif, sans biais de langue, doit être évalué en même temps que la performance scolaire. En utilisant des données recueillies auprès d’élèves luxembourgeois du cycle 3.2 (âge moyen de 10 ans, N = 280), nous montrerons que la performance d’élèves ayant eu des instructions non verbales (n = 136) est similaire à celle d’élèves ayant eu des instructions verbales (n = 144) sur une série de tâches de raisonnement logique. De plus, nous présenterons des observations sur la comparabilité de la version tablette tactile du test (n = 104) et de la version papier crayon (n = 176). Nous terminerons avec une réflexion critique des avantages et défis à relever dans l’utilisation de tablettes tactiles en situation de test. [less ▲]

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See detailA Game Theoretic Analysis of the Twitter Follow-Unfollow Mechanism
Chen, Jundong; Hossain, Md Shafaeat; Brust, Matthias R. UL et al

in International Conference on Decision and Game Theory for Security (2018)

Twitter users often crave more followers to increase their social popularity. While a variety of factors have been shown to attract the followers, very little work has been done to analyze the mechanism ... [more ▼]

Twitter users often crave more followers to increase their social popularity. While a variety of factors have been shown to attract the followers, very little work has been done to analyze the mechanism how Twitter users follow or unfollow each other. In this paper, we apply game theory to modeling the follow-unfollow mechanism on Twitter. We first present a two-player game which is based on the Prisoner’s Dilemma, and subsequently evaluate the payoffs when the two players adopt different strategies. To allow two players to play multiple rounds of the game, we propose a multi-stage game model. We design a Twitter bot analyzer which follows or unfollows other Twitter users by adopting the strategies from the multi-stage game. We develop an algorithm which enables the Twitter bot analyzer to automatically collect and analyze the data. The results from analyzing the data collected in our experiment show that the follow-back ratios for both of the Twitter bots are very low, which are 0.76% and 0.86%. This means that most of the Twitter users do not cooperate and only want to be followed instead of following others. Our results also exhibit the effect of different strategies on the follow-back followers and on the non-following followers as well. [less ▲]

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See detailAnnotation of Argument Components in Political Debates Data
Haddadan, Shohreh UL; Cabrio, Elena; Villata, Serena

in Proceedings of the Workshop on Annotation in Digital Humanities (2018)

n this paper, we present the annotation guidelines we defined for annotating arguments in political debates. In our guidelines, we consider each argument as being composed of a claim and one or more ... [more ▼]

n this paper, we present the annotation guidelines we defined for annotating arguments in political debates. In our guidelines, we consider each argument as being composed of a claim and one or more premises. The annotation process has started with defining the guidelines for three annotators containing examples from the data, and continued as cyclic process of evaluation and revision on the annotation to resolve the ambiguities in the guidelines. In this paper, we briefly discuss the resulting annotated dataset and give some examples of the annotation scheme. The quality of the annotated dataset is assessed by computing inter-annotator agreement using Krippendorf’s α coefficient on a portion of the dataset. [less ▲]

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See detailSome Reflections on a Computer-aided Theory Exploration Study in Category Theory (Extended Abstract)
Benzmüller, Christoph UL; Scott, Dana S.

in 3rd Conference on Artificial Intelligence and Theorem Proving (AITP 2018), Book of Abstracts (2018)

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See detailLate heartbeat-evoked potentials, indicators of cortical representation of interoceptive signal processing, are associated with survival after cardiac arrest
Schulz, André UL; Stammet, Pascal; Dierolf, Angelika UL et al

in Hennig, J.; Stark, R. (Eds.) Abstractband Psychologie und Gehirn 2018 (2018)

Rationale: Cardiac arrest (CA) is a serious condition characterized by high mortality rates, even after initial successful resuscitation, mainly due to neurological damage. Whether brain-heart ... [more ▼]

Rationale: Cardiac arrest (CA) is a serious condition characterized by high mortality rates, even after initial successful resuscitation, mainly due to neurological damage. Whether brain-heart communication is associated with outcome after CA is unknown. Heartbeat-evoked brain potentials (HEPs) represent neurophysiological indicators of brain-heart communication, as they reflect cortical representation of interoceptive signal processing. The aim of this study was to address the association between HEPs and survival after CA. Methods: HEPs were calculated from resting EEG/ECG in 55 CA patients 24 h after resuscitation. All patients were treated with targeted temperature management and a standardized sedation protocol during assessment. We investigated the association between HEP amplitude (180{320 ms, 455{595 ms, 860{1000 ms) and 6-month survival. Results: Twenty-five of 55 patients (45%) were still alive at 6-month follow-up. Survivors showed a higher HEP amplitude at frontopolar and frontal electrodes in the late HEP interval than non-survivors. This effect remained significant after controlling for between-group differences in terms of age, Fentanyl dose, and time lag between resuscitation and EEG assessment. There were no group differences in heart rate or heart rate variability. Conclusion: Brain-heart communication, as re ected by HEPs, is associated with survival after CA. Cardiovascular autonomic arousal may not be involved in mediating this effect. Adequate cortical representation of interoceptive signals may be essential to preserve cariovascular health and should be in the focus of prevention strategies. Future studies should address the brain-heart axis in CA. [less ▲]

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See detailRecent Progress Toward Intelligent Robot Assistants for Non-Destructive Disassembly
Jungbluth, Jan UL; Gerke, Wolfgang; Plapper, Peter UL

in Müller, Rainer; Plapper, Peter; Brüls, Olivier (Eds.) et al Robotix-Academy Conference for Industrial Robotics (RACIR) 2018 (2018)

One key to successful and fluent human-robot collaboration in disassembly processes is equipping the robot systems with greater autonomy and intelligence. In this paper, we present our progress in ... [more ▼]

One key to successful and fluent human-robot collaboration in disassembly processes is equipping the robot systems with greater autonomy and intelligence. In this paper, we present our progress in developing such an intelligent robot assistant system. We present the multi-agent control architecture we developed and describe its technical implementation. Our control approach relies on two types of knowledge models: product and process models. The product model describes the structure of the product to be dismantled through a description of the parts involved and the connections between them. A connection type-related process model describes which agents and objects participate in the disassembly process and which methods of human-robot cooperation or collaboration are most useful. When supplied with a product model and a goal definition, our robotic assistant can automatically generate a partially ordered disassembly task sequence. For each disassembly task, the user can choose one of the divisions of labor defined in the process model. Using the process model, through perception and deliberation, the control system can both execute actions and coordinate and synchronize the actions of human and machine. This approach allows the system to be more autonomous when providing assistance to human coworkers in complex and one-piece disassembly processes. [less ▲]

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See detailA Hybrid Algorithm for Multi-objective Test Case Selection in Regression Testing
Delavernhe, Florian; Saber, Takfarinas; Papadakis, Mike UL et al

in IEEE CONGRESS ON EVOLUTIONARY COMPUTATION (2018)

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See detailMutant Quality Indicators
Papadakis, Mike UL; Titcheu Chekam, Thierry UL; Le Traon, Yves UL

in 13th International Workshop on Mutation Analysis (MUTATION'18) (2018)

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See detailNumerical evaluation of the plastic hinges developed in headed stud shear connectors in composite beams with profiled steel sheeting
Vigneri, Valentino UL; Odenbreit, Christoph UL; Braun, Matthias Volker UL

in Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures (2018)

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load bearing capacity of the shear connector. This is due to the larger rib heights and the smaller ... [more ▼]

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load bearing capacity of the shear connector. This is due to the larger rib heights and the smaller rib widths in comparison with the old studies, which have been carried out to calibrate the current design equations. The RFCS Project “DISCCO” investigated this phenomena and the working group under mandate M515, CEN/TC250/SC4/SC4.T3 is enhancing this equation and working on a proposal to be taken over in the new version of Eurocode 4. The proposed new equation covers the failure behaviour of the shear connection more in detail. The test results show, that the failure consists in a combined concrete cone and stud in bending. Due to the geometry of novel steel sheeting, the load bearing capacity of the headed stud shear connector is no more limited by its shear capacity, but by its bending capacity. A 3D non-linear finite element model is developed and validated through the support of the DISCCO push-out tests. A good agreement between numerical and experimental results in terms of force-slip behaviour is achieved. Special attention of this work lies on the numerical evaluation of the number of plastic hinges ny: a stress-based procedure is presented and the results are compared to the equations presented for new Eurocode 4. The numerical simulations show that the upper plastic hinge moves up as the slip increases due to the progressive crushing of the concrete in the rib. From the parametric study, it turns out that ny is linearly proportional to the embedment depth. Compared to pre-punched hole decking, through-deck welding specimen activates less plastic hinges in the studs because of the higher stiffness provided at the base of the stud. [less ▲]

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See detailComputational Hermeneutics: Using Computers to Interpret Philosophical Arguments (Abstract)
Fuenmayor, David; Benzmüller, Christoph UL

in Logical Correctness, Workshop at UNILOG'2018, UNILOG'2018 Book of Abstracts (2018)

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See detailQuasi-Open Bisimilarity with Mismatch is Intuitionistic
Horne, Ross James UL; Ahn, Ki Yung; Lin, Shang-wei et al

in Proceedings of LICS '18: 33rd Annual ACM/IEEE Symposium on Logic in Computer Science, Oxford, United Kingdom, July 9-12, 2018 (LICS '18) (2018)

Quasi-open bisimilarity is the coarsest notion of bisimilarity for the π-calculus that is also a congruence. This work extends quasi-open bisimilarity to handle mismatch (guards with inequalities). This ... [more ▼]

Quasi-open bisimilarity is the coarsest notion of bisimilarity for the π-calculus that is also a congruence. This work extends quasi-open bisimilarity to handle mismatch (guards with inequalities). This minimal extension of quasi-open bisimilarity allows fresh names to be manufactured to provide constructive evidence that an inequality holds. The extension of quasi-open bisimilarity is canonical and robust --- coinciding with open barbed bisimilarity (an objective notion of bisimilarity congruence) and characterised by an intuitionistic variant of an established modal logic. The more famous open bisimilarity is also considered, for which the coarsest extension for handling mismatch is identified. Applications to checking privacy properties are highlighted. Examples and soundness results are mechanised using the proof assistant Abella. [less ▲]

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See detailInvestigating Fingerprinters and Fingerprinting-Alike Behaviour of Android Applications
Ferreira Torres, Christof UL; Jonker, Hugo

in 23rd European Symposium on Research in Computer Security, Barcelona, Spain, September 3-7, 2018 (2018)

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See detailOn the Reduction of Biases in Big Data Sets for the Detection of Irregular Power Usage
Glauner, Patrick UL; State, Radu UL; Valtchev, Petko et al

in Proceedings 13th International FLINS Conference on Data Science and Knowledge Engineering for Sensing Decision Support (FLINS 2018) (2018)

In machine learning, a bias occurs whenever training sets are not representative for the test data, which results in unreliable models. The most common biases in data are arguably class imbalance and ... [more ▼]

In machine learning, a bias occurs whenever training sets are not representative for the test data, which results in unreliable models. The most common biases in data are arguably class imbalance and covariate shift. In this work, we aim to shed light on this topic in order to increase the overall attention to this issue in the field of machine learning. We propose a scalable novel framework for reducing multiple biases in high-dimensional data sets in order to train more reliable predictors. We apply our methodology to the detection of irregular power usage from real, noisy industrial data. In emerging markets, irregular power usage, and electricity theft in particular, may range up to 40% of the total electricity distributed. Biased data sets are of particular issue in this domain. We show that reducing these biases increases the accuracy of the trained predictors. Our models have the potential to generate significant economic value in a real world application, as they are being deployed in a commercial software for the detection of irregular power usage. [less ▲]

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See detailFormal Analysis of Vote Privacy Using Computationally Complete Symbolic Attacker
Bana, Gergely UL; Chadha, Rohit; Eeralla, Ajay

in Computer Security (2018)

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See detailContext-aware and Attribute-based Access Control Applying Proactive Computing to IoT System
Picard, Noé UL; Colin, Jean-Noël; Zampunieris, Denis UL

in Proceedings of the 3rd International Conference on Internet of Things, Big Data and Security (IoTBDS 2018) (2018)

ABAC allows for high flexibility in access control over a system through the definition of policies based on attribute values. In the context of an IoT-based system, these data can be supplied through its ... [more ▼]

ABAC allows for high flexibility in access control over a system through the definition of policies based on attribute values. In the context of an IoT-based system, these data can be supplied through its sensors connected to the real world, allowing for context-awareness. However, the ABAC model alone does not include proposals for implementing security policies based on verified and/or meaningful values rather than on raw data flowing from the sensors. Nor does it allow to implement immediate action on the system when some security flaw is detected, while this possibility technically exists if the system is equipped with actuators next to its sensors. We show how to circumvent these limitations by adding a proactive engine to the ABAC components, that runs rule-based scenarios devoted to sensor data pre-processing, to higher-level information storage in the PIP, and to real-time, automatic reaction on the system through its actuators when required. [less ▲]

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See detailSymbolisation and objectification through social interactions for meaningful learning of mathematics
Vlassis, Joëlle UL; Demonty, Isabelle

in Proceedings of the 42nd Conference of the International Group for the Psychology of Mathematics Education (2018)

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