References of "Scientific congresses, symposiums and conference proceedings"
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See detailThe stability of academic self-concept profiles – a latent transition analysis
Franzen, Patrick UL; Arens, A. Katrin; Niepel, Christoph UL

Poster (2019, November 06)

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See detailSimilarities and differences of value-added scores from models with different covariates: A cluster analysis
Levy, Jessica UL; Brunner, Martin; Keller, Ulrich UL et al

Scientific Conference (2019, November 06)

Detailed reference viewed: 56 (4 UL)
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See detailMath and Reading Difficulties in a Multilingual Educational Setting
Martini, Sophie Frédérique UL; Fischbach, Antoine UL; Ugen, Sonja UL

Scientific Conference (2019, November 06)

Detailed reference viewed: 43 (3 UL)
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See detailNeed for Cognition across school tracks: The importance of learning environments
Colling, Joanne UL; Wollschläger, Rachel UL; Keller, Ulrich UL et al

Scientific Conference (2019, November 06)

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See detailOptimum Design for Sparse FDA-MIMO Automotive Radar
Sedighi, Saeid UL; Shankar, Bhavani UL; Mishra, Kumar Vijay et al

in Sedighi, Saeid; Shankar, Bhavani; Mishra, Kumar Vijay (Eds.) et al Optimum Design for Sparse FDA-MIMO Automotive Radar (2019, November 03)

Automotive radars usually employ multiple-input multiple-output (MIMO) antenna arrays to achieve high azimuthal resolution with fewer elements than a phased array. Despite this advantage, hardware costs ... [more ▼]

Automotive radars usually employ multiple-input multiple-output (MIMO) antenna arrays to achieve high azimuthal resolution with fewer elements than a phased array. Despite this advantage, hardware costs and desired radar size limits the usage of more antennas in the array. Similar trade-off is encountered while attempting to achieve high range resolution which is limited by the signal bandwidth. However, nowadays given the demand for spectrum from communications services, wide bandwidth is not readily available. To address these issues, we propose a sparse variant of Frequency Diverse Array MIMO (FDA-MIMO) radar which enjoys the benefits of both FDA and MIMO techniques, including fewer elements, decoupling, and efficient joint estimation of target parameters. We then employ the Cram\'{e}r-Rao bound for angle and range estimation as a performance metric to design the optimal antenna placement and carrier frequency offsets for the transmit waveforms. Numerical experiments suggest that the performance of sparse FDA-MIMO radar is very close to the conventional FDA-MIMO despite 50\% reduction in the bandwidth and antenna elements. [less ▲]

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See detailActive Content Popularity Learning via Query-by-Committee for Edge Caching
Bommaraveni, Srikanth UL; Vu, Thang; Vuppala, Satyanarayana et al

Scientific Conference (2019, November 03)

Edge caching has received much attention as an effective solution to face the stringent latency requirements in 5G networks due to the proliferation of handset devices as well as data-hungry applications ... [more ▼]

Edge caching has received much attention as an effective solution to face the stringent latency requirements in 5G networks due to the proliferation of handset devices as well as data-hungry applications. One of the challenges in edge caching systems is to optimally cache strategic contents to maximize the percentage of total requests served by the edge caches. To enable the optimal caching strategy, we propose an Active Learning approach (AL) to learn and design an accurate content request prediction algorithm. Specifically, we use an AL based Query-by-committee (QBC) matrix completion algorithm with a strategy of querying the most informative missing entries of the content popularity matrix. The proposed AL framework leverage's the trade-off between exploration and exploitation of the network, and learn the user's preferences by posing queries or recommendations. Later, it exploits the known information to maximize the system performance. The effectiveness of proposed AL based QBC content learning algorithm is demonstrated via numerical results. [less ▲]

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See detailEnergy-efficient Trajectory Design for UAV-enabled Wireless Communications with Latency Constraints
Tran Dinh, Hieu UL; Vu, Thang Xuan UL; Chatzinotas, Symeon UL et al

Scientific Conference (2019, November 03)

This paper studies a new energy-efficient unmanned aerial vehicle (UAV)-enabled wireless communications, where the UAV acts as a flying base station (BS) to serve the ground users (GUs) within some ... [more ▼]

This paper studies a new energy-efficient unmanned aerial vehicle (UAV)-enabled wireless communications, where the UAV acts as a flying base station (BS) to serve the ground users (GUs) within some predetermined latency limitations, e.g., requested timeout (RT). Our goal is to design the UAV trajectory to minimize the total energy consumption while satisfying the RT requirement from every GU, which is accomplished via two consecutive subproblems: traveling time minimization and energy minimization problems. Firstly, we propose two exhaustive search and heuristic algorithms based on the traveling salesman problem with time window (TSPTW) in order to minimize the UAV’s traveling time without violating the GUs’ RT requirements. While the exhaustive algorithm achieves the best performance at a high computation cost, the heuristic algorithm achieves a trade-off between the performance and complexity. Secondly, we minimize the total energy consumption, for a given trajectory, via a joint optimization of the UAV’s velocity along subsequent hops. Finally, numerical results are presented to demonstrate the effectiveness of our proposed algorithms. In particular, it is shown that the proposed solutions outperform the reference in terms of both energy consumption and outage performance. [less ▲]

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See detailHardware Precoding Demonstration in Multi-Beam UHTS Communications under Realistic Payload Characteristics
Merlano Duncan, Juan Carlos UL; Querol Borras, Jorge UL; Maturo, Nicola UL et al

in Proceedings of the 37th International Communications Satellite Systems Conference (2019, November 01)

In this paper, we present a new hardware test-bed to demonstrate closed-loop precoded communications for interference mitigation in multi-beam ultra high throughput satellite systems under realistic ... [more ▼]

In this paper, we present a new hardware test-bed to demonstrate closed-loop precoded communications for interference mitigation in multi-beam ultra high throughput satellite systems under realistic payload and channel impairments. We build the test-bed to demonstrate a real-time channel aided precoded transmission under realistic conditions such as the power constraints and satellite-payload non-linearities. We develop a scalable architecture of an SDR platform with the DVB-S2X piloting. The SDR platform consists of two parts: analog-to-digital (ADC) and digital-to-analog (DAC) converters preceded by radio frequency (RF) front-end and Field-Programmable Gate Array (FPGA) backend. The former introduces realistic impairments in the transmission chain such as carrier frequency and phase misalignments, quantization noise of multichannel ADC and DAC and non-linearities of RF components. It allows evaluating the performance of the precoded transmission in a more realistic environment rather than using only numerical simulations. We benchmark the performance of the communication standard in realistic channel scenarios, evaluate received signal SNR, and measure the actual channel throughput using LDPC codes. [less ▲]

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See detailVon Eupen-Malmedy nach Ostbelgien. Eine deutsch-belgische Beziehungsgeschichte seit 1920
Brüll, Christoph UL

Scientific Conference (2019, November 01)

Detailed reference viewed: 65 (1 UL)
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See detailA Personalized Sentiment Model with Textual and Contextual Information
Guo, Siwen UL; Höhn, Sviatlana UL; Schommer, Christoph UL

in The SIGNLL Conference on Computational Natural Language Learning, Hong Kong 3-4 November 2019 (2019, November)

In this paper, we look beyond the traditional population-level sentiment modeling and consider the individuality in a person's expressions by discovering both textual and contextual information. In ... [more ▼]

In this paper, we look beyond the traditional population-level sentiment modeling and consider the individuality in a person's expressions by discovering both textual and contextual information. In particular, we construct a hierarchical neural network that leverages valuable information from a person's past expressions, and offer a better understanding of the sentiment from the expresser's perspective. Additionally, we investigate how a person's sentiment changes over time so that recent incidents or opinions may have more effect on the person's current sentiment than the old ones. Psychological studies have also shown that individual variation exists in how easily people change their sentiments. In order to model such traits, we develop a modified attention mechanism with Hawkes process applied on top of a recurrent network for a user-specific design. Implemented with automatically labeled Twitter data, the proposed model has shown positive results employing different input formulations for representing the concerned information. [less ▲]

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See detailA New Optimization Tool for Mega-Constellation Design and its Application to Trunking Systems
Kisseleff, Steven UL; Shankar, Bhavani UL; Spano, Danilo UL et al

in 37th International Communications Satellite Systems Conference (ICSSC), Japan, October 2019 (2019, November)

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See detailUser Terminal Wideband Modem for Very High Throughput Satellites
Kisseleff, Steven UL; Maturo, Nicola UL; Chatzinotas, Symeon UL et al

in 37th International Communications Satellite Systems Conference (ICSSC), Japan, October 2019 (2019, November)

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See detailA Multilayer Low-Altitude Airspace Model for UAV Traffic Management
Samir Labib, Nader UL; Danoy, Grégoire UL; Musial, Jedrzej et al

in Samir Labib, Nader; Danoy, Grégoire; Musial, Jedrzej (Eds.) et al 9th ACM Symposium on Design and Analysis of Intelligent Vehicular Networks and Applications (DIVANet '19) (2019, November)

Over the recent years, Unmanned Aerial Vehicles' (UAVs) technology developed rapidly. In turn shedding light on a wide range of potential civil and commercial applications ranging from mapping and ... [more ▼]

Over the recent years, Unmanned Aerial Vehicles' (UAVs) technology developed rapidly. In turn shedding light on a wide range of potential civil and commercial applications ranging from mapping and surveillance, parcel delivery to more demanding ones that require UAVs to operate in heterogeneous swarms. However, with the great advantages UAVs bring, they are expected to soon dominate the shared, low-altitude airspace over populated cities, introducing multiple new research challenges in safely managing the unprecedented traffic demands. The main contribution of this work is addressing the complex problem of UAV traffic management at an abstract level by proposing a structure for the uncontrolled low-altitude airspace. The paper proposes a model of the airspace as a weighted multilayer network of nodes and airways and presents a set of experimental simulations of UAV traffic for the verification and validation of the model. Finally, the paper outlines our intended future work. [less ▲]

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See detailGraceful Interactions and Social Support as Motivational Design Strategies to Encourage Women in Exercising
Menheere, Daphne; Lallemand, Carine UL; Faber, Ilse et al

Scientific Conference (2019, November)

Increasingly aware of the importance of active lifestyles, many people intend to exercise more. Yet the main challenge remains to translate these intentions into action. Wearable devices supporting ... [more ▼]

Increasingly aware of the importance of active lifestyles, many people intend to exercise more. Yet the main challenge remains to translate these intentions into action. Wearable devices supporting exercise regrettably tend to adopt a one-size-fits-all approach by monitoring activity through quantified data as a motivation strategy. Since certain individuals are driven by social motives to exercise, less addressed through quantification, the impact of these devices on user experience and motivation is questionable. We contribute to the field by defining interaction attributes of graceful interactions in product design. We then embedded these in designing Grace, a piece of jewelry enabling women to share exercise intentions with friends to encourage social support. Instead of focusing on quantification, we rely on a qualitative approach using graceful interaction. Through this we extend the design space of sport-related wearables for women and inform how to design for exercise motivation through social support and graceful interactions. [less ▲]

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See detailCrowdSenSim 2.0: a Stateful Simulation Platform for Mobile Crowdsensing in Smart Cities
Montori, Federico; Cortesi, Emanuele; Bedogni, Luca et al

in MSWIM '19: Proceedings of the 22nd International ACM Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems, Miami Beach, FL, USA, 2019. (2019, November)

Mobile crowdsensing (MCS) has become a popular paradigm for data collection in urban environments. In MCS systems, a crowd supplies sensing information for monitoring phenomena through mobile devices ... [more ▼]

Mobile crowdsensing (MCS) has become a popular paradigm for data collection in urban environments. In MCS systems, a crowd supplies sensing information for monitoring phenomena through mobile devices. Typically, a large number of participants is required to make a sensing campaign successful. For such a reason, it is often not practical for researchers to build and deploy large testbeds to assess the performance of frameworks and algorithms for data collection, user recruitment, and evaluating the quality of information. Simulations offer a valid alternative. In this paper, we present CrowdSenSim 2.0, a significant extension of the popular CrowdSenSim simulation platform. CrowdSenSim 2.0 features a stateful approach to support algorithms where the chronological order of events matters, extensions of the architectural modules, including an additional system to model urban environments, code refactoring, and parallel execution of algorithms. All these improvements boost the performances of the simulator and make the runtime execution and memory utilization significantly lower, also enabling the support for larger simulation scenarios. We demonstrate retro-compatibility with the older platform and evaluate as a case study a stateful data collection algorithm. [less ▲]

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See detailFeasibility of Stellar as a Blockchain-based Micropayment System
Khan, Nida UL; Ahmad, Tabrez; State, Radu UL

in Springer SmartBlock 2019 - 2nd International Conference on Smart Blockchain (2019, November)

The advent of Bitcoin was heralded as an innovation in the global monetary system, that could bring down transaction fees by circumventing the need for third parties and conduct transactions in real time ... [more ▼]

The advent of Bitcoin was heralded as an innovation in the global monetary system, that could bring down transaction fees by circumventing the need for third parties and conduct transactions in real time. The divisibility of a blockchain cryptocurrency to even fractions of a cent, caused microtransactions to become feasible to formerly non-existent denominations. These microtransactions have spurred the development of novel ways of monetizing online resources and hold the potential to aid in alleviation of poverty. The paper conducts a feasibility study on Stellar as a blockchain-based micropayment system. It highlights the computational and other issues that impedes its progress and utilizes a characterization model for micropayment systems to evaluate the efficacy of the Stellar platform. The paper conducts a comparison with the micropayment solutions from Bitcoin, Ethereum and PayPal. The paper analyzes a subset of transactions from the Stellar blockchain to aid in drawing a conclusion on the undertaken study and elaborates on the mitigation tools to enable fraud prevention in online monetary transactions. [less ▲]

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See detailTowards Dynamic Zero Emission Zone Management for Plug-in Hybrid Buses
Seredynski, Marcin UL; Viti, Francesco UL

Scientific Conference (2019, November)

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See detailCharacterization of the MSE Region under a Total Power Budget for Asynchronous Two-Way Relay Networks
Rahimi, Razgar; Shahbazpanahi, Shahram UL; Ottersten, Björn UL

in The Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, CA, 3-6 November 2019 (2019, November)

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See detailCrafting Conversational Agents' Personality in a User-Centric Context
Mano Ferreira, Cátia; Höhn, Sviatlana UL

in Proceedings of the 31st Benelux Conference on Artificial Intelligence (BNAIC 2019) and the 28th Belgian Dutch Conference on Machine Learning (Benelearn 2019) (2019, November)

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See detailAssessing the Generalizability of code2vec Token Embeddings
Kang, Hong Jin; Bissyande, Tegawendé François D Assise UL; David, Lo

in Proceedings of the 34th IEEE/ACM International Conference on Automated Software Engineering (2019, November)

Many Natural Language Processing (NLP) tasks, such as sentiment analysis or syntactic parsing, have benefited from the development of word embedding models. In particular, regardless of the training ... [more ▼]

Many Natural Language Processing (NLP) tasks, such as sentiment analysis or syntactic parsing, have benefited from the development of word embedding models. In particular, regardless of the training algorithms, the learned embeddings have often been shown to be generalizable to different NLP tasks. In contrast, despite recent momentum on word embeddings for source code, the literature lacks evidence of their generalizability beyond the example task they have been trained for. In this experience paper, we identify 3 potential downstream tasks, namely code comments generation, code authorship identification, and code clones detection, that source code token embedding models can be applied to. We empirically assess a recently proposed code token embedding model, namely code2vec’s token embeddings. Code2vec was trained on the task of predicting method names, and while there is potential for using the vectors it learns on other tasks, it has not been explored in literature. Therefore, we fill this gap by focusing on its generalizability for the tasks we have identified. Eventually, we show that source code token embeddings cannot be readily leveraged for the downstream tasks. Our experiments even show that our attempts to use them do not result in any improvements over less sophisticated methods. We call for more research into effective and general use of code embeddings. [less ▲]

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See detailEnhanced Sketchnoting through Semantic Integration of Learning Material
Atashpendar, Aryobarzan UL; Grevisse, Christian UL; Rothkugel, Steffen UL

in Applied Informatics (2019, November)

Within the transition from pen-and-paper to digital solutions, many tablet-based note-taking apps have been developed. In addition, sketchnoting, a highly visual form of note-taking, has gained in ... [more ▼]

Within the transition from pen-and-paper to digital solutions, many tablet-based note-taking apps have been developed. In addition, sketchnoting, a highly visual form of note-taking, has gained in popularity, especially in teaching and learning. While current solutions already reduce the burden of organizing and searching through stacks of paper, they provide little support in finding additional information related to the notes, and search capabilities are mostly limited to textual queries and content. In this paper, we present a novel solution for digital sketchnoting aimed at enhancing the learning experience of students. In addition to common capabilities such as handwriting recognition, our note-taking app integrates semantic annotation and drawing recognition. Handwritten notes are recognized and passed through concept recognition and entity linking tools to enable a knowledge graph-based integration of contextually relevant learning resources. We extend traditional search capabilities by including the semantic metadata from the related material as well as enabling visual queries to find recognized sketches. Finally, resembling the exchange of paper notes among students, our app allows to share the semantically enhanced notes with other devices. [less ▲]

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See detailITU Framework: A Model for an International Regime of Space Resources?
Hofmann, Mahulena UL

in Hofmann, Mahulena (Ed.) Proceedings of the 61th Colloquium on the Law of Outer Space (2019, November)

The contribution examines which elements of the ITU framework would be transferable to the future international regime of space resources activities. First, it gives a short description of space resources ... [more ▼]

The contribution examines which elements of the ITU framework would be transferable to the future international regime of space resources activities. First, it gives a short description of space resources activities, followed by an overview of the ITU regime, which may be relevant from the perspective of space mining. Furthermore, it describes the provisions elaborated by The Hague Space Resources Governance Group, the Building Blocks, which show several resemblances with the ITU regime. [less ▲]

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See detailConsistent Rational Argumentation in Politics (CRAP)
Benzmüller, Christoph UL; Steen, Alexander UL

Poster (2019, November)

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See detailEffectiveness of bullying intervention teams in German schools
Böhmer, Matthias UL; Franck, André; Schirra, Helmut et al

Scientific Conference (2019, November)

In recent years, bullying has increasingly been recognized as a widespread problem - also in the school context. Numerous examples illustrate that bullying at school is not an unfortunate individual case ... [more ▼]

In recent years, bullying has increasingly been recognized as a widespread problem - also in the school context. Numerous examples illustrate that bullying at school is not an unfortunate individual case, but is often part of everyday school life. Large-scale international comparative studies such as HBSC underline the high bullying prevalence rate and thus the relevance of the topic. According to these studies, classmates bully every sixth child in Germany several times a week. Teachers have a special responsibility in dealing with bullying. As a rule, they are at the center of the action and have the task of recognizing bullying in good time and of (re)acting quickly, decisively and reflectively. Since bullying is a complex phenomenon, professional action in this area poses a major challenge. For this reason, a program against bullying introduced in some federal states explicitly aims at teachers who are trained as bullying intervention teams on three days. Currently, we are systematically evaluating this program. In particular, we are interested in the extent to which the previous knowledge of teachers on the subject of mobbing is transformed by the program into consolidated knowledge relevant for acting and decision-making. In connection with the intervention of teachers in the case of bullying, there is (a) the expression of their expectation of self-efficacy, (b) the teaching climate, i.e. the social climate in teaching situations in a class, and (c) the experience and behavior of their students. We will present and discuss first results of the effectiveness of the program. [less ▲]

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See detailPrivacy Aspects and Subliminal Channels in Zcash
Biryukov, Alex UL; Feher, Daniel UL; Vitto, Giuseppe UL

in Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Securit (2019, November)

In this paper we analyze two privacy and security issues for the privacy-oriented cryptocurrency Zcash. First we study shielded transactions and show ways to fingerprint user transactions, including ... [more ▼]

In this paper we analyze two privacy and security issues for the privacy-oriented cryptocurrency Zcash. First we study shielded transactions and show ways to fingerprint user transactions, including active attacks.We introduce two new attacks which we call Danaan-gift attack and Dust attack. Following the recent Sapling update of Zcash protocol we study the interaction between the new and the old zk-SNARK protocols and the effects of their interaction on transaction privacy. In the second part of the paper we check for the presence of subliminal channels in the zk-SNARK protocol and in Pedersen Commitments. We show presence of efficient 70-bit channels which could be used for tagging of shielded transactions which would allow the attacker (malicious transaction verifier) to link transactions issued by a maliciously modified zk-SNARK prover, while would be indistinguishable from regular transactions for the honest verifier/user. We discuss countermeasures against both of these privacy issues. [less ▲]

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See detailFour Jewish stateless families between the millstones of Luxembourg authorities
Scuto, Denis UL; Bronec, Jakub UL

Scientific Conference (2019, November)

Our research, among others, attempts to find answers to the questions: How Luxembourg administration dealt with Jewish refugees who had lost their citizenship arriving to the Grand Duchy of Luxembourg ... [more ▼]

Our research, among others, attempts to find answers to the questions: How Luxembourg administration dealt with Jewish refugees who had lost their citizenship arriving to the Grand Duchy of Luxembourg from the East. Were there any particular differences between genders in the process of acceptance? Did Luxembourgish authorities distinguish or give priority to citizens of particular nations? [less ▲]

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See detailVPGA: an SDN-based Location Privacy Zones Placement Scheme for Vehicular Networks
Boualouache, Abdelwahab UL; Soua, Ridha UL; Engel, Thomas UL

in 38th IEEE International Performance Computing and Communications Conference (IPCCC) (2019, October 29)

Making personal data anonymous is crucial to ensure the adoption of connected vehicles. One of the privacy-sensitive information is location, which once revealed can be used by adversaries to track ... [more ▼]

Making personal data anonymous is crucial to ensure the adoption of connected vehicles. One of the privacy-sensitive information is location, which once revealed can be used by adversaries to track drivers during their journey. Vehicular Location Privacy Zones (VLPZs) is a promising approach to ensure unlinkability. These logical zones can be easily deployed over roadside infrastructures (RIs) such as gas station or electric charging stations. However, the placement optimization problem of VLPZs is NP-hard and thus an efficient allocation of VLPZs to these RIs is needed to avoid their overload and the degradation of the QoS provided within theses RIs. This work considers the optimal placement of the VLPZs and proposes a genetic-based algorithm in a software defined vehicular network to ensure minimized trajectory cost of involved vehicles and hence less consumption of their pseudonyms. The analytical evaluation shows that the proposed approach is cost-efficient and ensures a shorter response time. [less ▲]

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See detailTeachers’ translanguaging stance, design, and shifts in a professional development course
Aleksic, Gabrijela UL; Bebic, Dzoen Dominique UL

Scientific Conference (2019, October 28)

Classrooms in Luxembourg are highly socially, culturally, and linguistically diverse. About 65% of 4 year-old children do not speak Luxembourgish, of which 28% speak Portuguese (MENJE, 2018). In 2017, the ... [more ▼]

Classrooms in Luxembourg are highly socially, culturally, and linguistically diverse. About 65% of 4 year-old children do not speak Luxembourgish, of which 28% speak Portuguese (MENJE, 2018). In 2017, the new law has declared multilingual early education mandatory. Until that time, the focus was solely on the development of Luxemburgish, whereas now teachers should also familiarize children with French and value their home languages. To support preschool teachers, our project aims to: (1) offer a professional development (PD) course in translanguaging, (2) involve children’s families to reinforce home-school collaboration, and (3) foster children’s cognitive, linguistic, and socio-emotional engagement in the classroom. We use focus groups, questionnaires, and language portraits with teachers and a test in early literacy and numeracy in school and home language and video observations with children. Translanguaging, the main topic of our 22 hour PD course (June – December 2019), is the use of a full linguistic repertoire to make meaning (Otheguy, García, & Reid, 2015). Through focus groups, we identified teachers’ negative translanguaging stance towards children’s proficiency in their home language that hinders the development of Luxembourgish. Translanguaging design was related to teachers’ use of multilingual stories and morning greetings, while translanguaging shifts concerned frequent translations by involving older children. Our main goal is to address the negative translanguaging stance by offering practical activities during the course and collaborating with parents, children, and organisational stakeholders. References Ministry of National Education, Childhood and Youth [MENJE]. (2018). Key numbers of the national education: statistics and indicators – School year 2016-2017. Retrieved from http://www.men.public.lu/fr/actualites/publications/themes-transversaux/statistiques-analyses/chiffres-cles/index.html Otheguy, R., García, O., & Reid, W. (2015). Clarifying translanguaging and deconstructing named languages: A perspective from linguistics. Applied Linguistic Review, 6(3), 281–307. [less ▲]

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See detailRebuilding the Office around the Mainframe: IBM’s S/360 in Context
van Herck, Sytze UL

Scientific Conference (2019, October 27)

The Oxford English Dictionary states that originally, a mainframe only defined the central processing unit and primary memory of a computer, whereas now a mainframe describes any large or general-purpose ... [more ▼]

The Oxford English Dictionary states that originally, a mainframe only defined the central processing unit and primary memory of a computer, whereas now a mainframe describes any large or general-purpose computer, specifically supporting numerous peripherals or subordinate computers. The IBM System/360, announced in 1964 and first installed at around 1967, consists of a collection of peripherals that can be connected to any central processing unit in the system family. Due to the size of both the individual components and the entire system, the design and layout of the office often needed to accommodate for the machine. Furthermore, “the experiences of weight, surface texture, sound and smell are part of the physicality of object” (Dannehl 2013, 130) so in order to experience the environment of a designated computer room, several museums have reconstructed at least some of the structure of a computer room. At the Living Computers Museum+Labs in Seattle the entrance to the separately airconditioned room is up a ramp, because of the raised floor that supports the weight of the computer and hides the very thick cables. Purchasing and installing an IBM System/360 required careful planning in terms of physical requirements and site selection, taking into account environmental, electrical, and signal factors. Besides the system and associated personnel, other furniture including storage cabinets, work tables, chairs, and desks also influenced planning. Furthermore, the length of the cables connecting the machines limited the distance between the system components. The schedule proposed by IBM encouraged customers to order six months before delivery and finalizing the layout two months later to allow for building alterations and time to process the cable order (IBM, 1975). Once the machine was installed, the dimensions and layout continuously influenced the workflow and working conditions of the users. Dannehl, Karin. 2013. “Object biographies. From production to consumption.” In History and Material Culture: A Student’s Guide to Approaching Alternative Sources, edited by Harvey, Karen, 123-138. Routledge. IBM System/360 Model 20 Installation Manual-Physical Planning. Systems Reference Library. Atlanta, Georgia: International Business Machines Corporation, 1975. Living Computers Museum+Labs, IBM, Box 1, 76027. [less ▲]

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See detailFacing parallel inventions: the French telecommunications strategies in the digital field (mid-1950s to mid-1990s)
Schafer, Valerie UL

Scientific Conference (2019, October 26)

This panel on parallel inventions is an opportunity to rethink 15-years of research on data networks and digitization from the perspective of simultaneity. The subject of parallel inventions in the field ... [more ▼]

This panel on parallel inventions is an opportunity to rethink 15-years of research on data networks and digitization from the perspective of simultaneity. The subject of parallel inventions in the field of data networks immediately brings to mind the outset of packet switching, a key concept of Arpanet and Internet (Bay, 2019) that was developed in the 1960s by several players, namely Paul Baran at the RAND Corporation, Leonard Kleinrock at UCLA and Donald Davies at the NPL (National Physical Laboratory) in Great Britain. Yet this Zeitgeist surrounding packet switching is not the only example of parallel ideas and projects within the history of data networks, nor is it limited to the US context. My presentation therefore aims to shift the focus to deepen our understanding of simultaneous inventions, turning away from the cumbersome examination of the “great figures” towards collective innovation and adoption. To do so, we will look at the telecommunications sector. Since the 1950s, this sector in the United States, France, Great Britain and other European countries has been confronted with computer needs and the challenge of building data networks based on their infrastructure – communication lines were mainly monopolized by telecommunication companies in Europe until the end of the 1980s. Several parallel paths were experimented during the period from the transition to electronic switching in phone equipment to the development of standards such as X25, which competed with Internet protocols in the 1980s and 1990s, demonstrating that innovation is not a linear process. Rather than discuss AT&T’s hostility towards packet switching as implemented in Arpanet, which has already been well documented (Abbate, 1999), this study will look at the French telecommunications administration and show how those responsible for the communication lines needed for French networks were positioning themselves to face the changes that had begun in the 1950s, whilst assessing parallel inventions that were either internal or external to the administration. Our paper will therefore focus less on invention per se than on the response to simultaneous inventions, and will review several simultaneous paths in the history of digital networks that French telecommunications had to face, and the associated process of collective decision-making. We will start by presenting the parallel development of spatial and temporal switching in the second half of the 1950s, then look at the simultaneous experiment of Caducée and Hermès networks (early 1970s). Complementary case studies will cover the debate about virtual circuits and datagrams from the 1970s to the 1990s, standardization within the field of telematics and the first Web offers in the transition period from the Minitel to the Web in the 1990s. Our analysis aims to establish a typology of the administration’s choices and attitudes, which differ according to whether the alternative is an internal solution or from an external source, but also according to the periods, from the telecommunications monopoly to the 1990s deregulation. In this way, we aim to reveal how inventions were not only connected to the technical context and knowledge, but were also shaped by those who were interested in the resulting technology. [less ▲]

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See detailThe Occupied Museum. Culture and Science in Luxemburg during the Nazi Occupation, 1940–1944
Spirinelli, Fabio UL

Scientific Conference (2019, October 24)

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See detailInformation Content of Systematic and Idiosyncratic Risk Disclosure
Weber, Véronique UL; Muessig, Anke UL

Scientific Conference (2019, October 24)

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See detailThe association between workplace bullying exposure and workplace bullying perpetration – The role of frustration of the need for relatedness
Sischka, Philipp UL; Steffgen, Georges UL

Scientific Conference (2019, October 24)

Workplace bullying (WB) is a serious phenomenon that has serious detrimental effects on victim’s health, attitudes, and work-related behavior (Nielsen & Einarsen, 2012). WB is seen as an escalated ... [more ▼]

Workplace bullying (WB) is a serious phenomenon that has serious detrimental effects on victim’s health, attitudes, and work-related behavior (Nielsen & Einarsen, 2012). WB is seen as an escalated conflict, where both parties engage in increasing overt acts of aggression (e.g., Einarsen et al., 2011). This perspective is supported by one of the most robust finding in WB and aggression literature, the association between experienced workplace aggression and enacting in workplace aggression (e.g., Baillien et al., 2016). However, there are only a few studies that have researched the mechanism between these phenomena (Samnani & Singh 2012). Self-determination theory (SDT) might explain this link. As need frustration is linked to less self-control (Vansteenkiste & Ryan, 2012), the frustration of the need for relatedness might also lead to increased aggressive behavior. Drawing on SDT, we propose that bullying exposure thwarts employee’s need for relatedness that increase aggressive behavior. Thus, the aim of our study was to test this mediation in a longitudinal design with short time intervals (i.e. monthly). A six-wave online survey design with monthly time lag was employed and data were collected among U.S. employees. The sample consists of 1,595 respondents (55.8% females, n=890, ageM = 36.9, ageSD =10.3). Workplace bullying exposure was assessed with the S-NAQ (Notelaers et al., 2018). Being a perpetrator of bullying was measured by the same nine items of the S-NAQ, however, formulated in an active manner (e.g., Baillien et al., 2011). Finally, frustration of the need for relatedness was assessed with the Psychological Needs Thwarting Scale (Bartholomew et al., 2011). Cross-lagged mediation analysis within a path modeling framework only partially confirmed the proposed model: WB exposure was significantly related to a change in frustration of relatedness. However, frustration of relatedness did (most of the time) not increase WB perpetration, but WB exposure. These longitudinal findings underline the vicious circle nature of WB exposure. [less ▲]

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See detailPrivacy-Preserving Processing of Filtered DNA Reads
Fernandes, Maria UL; Decouchant, Jérémie UL; Volp, Marcus UL et al

Scientific Conference (2019, October 22)

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See detailrom Text to Bits: Making the Treaties of a Monk from the 16th Century "Understandable" to the Computer
Dubuisson, Bastian UL

Scientific Conference (2019, October 19)

Historians who aspire to explore texts with the help of the computer are more than often confronted to the absence of machine-readable corpora to suit their needs. As such, the early 16th century Latin ... [more ▼]

Historians who aspire to explore texts with the help of the computer are more than often confronted to the absence of machine-readable corpora to suit their needs. As such, the early 16th century Latin treaties about the city of Trier and its relics by the Benedictine monk Johannes Scheckmann are no exception. Despite their historical importance, among others for the study of the religious phenomenon during this pivotal era, these texts remain in their original form. Optical Character Recognition software makes it possible to overcome this gap by translating printed or handwritten characters into encoded glyphs, but not at any cost. Creating a digital corpus requires a careful reflection, particularly when it comes to small scale projects. Moreover, Latin being a highly inflected language, further post-processing steps such as tokenization and lemmatization are necessary in order to finally be able to process a corpus of texts with lines of code. During the digital transformation, each step leads to a profound but necessary modification of the original text and the creation of new data. The example of Scheckmann’s works illustrates what is lost when a text is turned into bits, as well as what can be discovered once the machine reads. [less ▲]

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See detailSoftware Engineering for Dataset Augmentation using Generative Adversarial Networks
Jahic, Benjamin UL; Guelfi, Nicolas UL; Ries, Benoît UL

in Proceedings of 10th IEEE International Conference on Software Engineering and Service Science (2019, October 19)

Software engineers require a large amount of data for building neural network-based software systems. The engineering of these data is often neglected, though, it is a critical and time-consuming activity ... [more ▼]

Software engineers require a large amount of data for building neural network-based software systems. The engineering of these data is often neglected, though, it is a critical and time-consuming activity. In this work, we present a novel software engineering approach for dataset augmentation using neural networks. We propose a rigorous process for generating synthetic data to improve the training of neural networks. Also, we demonstrate our approach to successfully improve the recognition of handwritten digits using conditional generative adversarial networks (cGAN). Finally, we shortly discuss selected important issues of our process, presenting related work and proposing some improvements. [less ▲]

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See detailRussische Immigration nach Luxemburg 1918-1935: Einwanderer aus einem nicht-existierenden Land
Ganschow, Inna UL

Scientific Conference (2019, October 18)

Die Einwanderer_innen aus dem früheren Russischen Reich trugen zur Arbeiterlandschaft im Süden, Norden und Osten Luxemburgs nach dem Ersten Weltkrieg bei. Nimmt man diese „Russen“ genauer unter die Lupe ... [more ▼]

Die Einwanderer_innen aus dem früheren Russischen Reich trugen zur Arbeiterlandschaft im Süden, Norden und Osten Luxemburgs nach dem Ersten Weltkrieg bei. Nimmt man diese „Russen“ genauer unter die Lupe, zeigen sich mindestens drei neue Gruppen, die die bereits vor 1914 bestehende russische Gemeinde vergrößerten. Die ersten sind die ehemaligen Kriegsgefangenen aus den Lagern in Frankreich, Belgien und Deutschland. Ein Teil ist vor Kriegsende als Flüchtlinge im Lande, die anderen kommen nach dem Waffenstillstand im November 1918. Sie wollen nicht zurück nach Russland, wo der Bürgerkriegt tobt. Die zweite Gruppe kommt im Laufe des Bürgerkrieges um 1926-1929 aus Bulgarien und Serbien nach. Es handelt sich um noch zusammenhaltende Weißgardisten, die zu der über die Krim in die Türkei evakuierte Armee von Petr Wrangel gehörten. Schließlich ist die dritte Gruppe der zivilen politischen Flüchtlinge zu erwähnen, die seit den frühen 1920ern meistens über Deutschland nach Luxemburg kamen und öfters Angehörigen der jüdischen Glaubensgemeinschaft waren. Viele von ihnen sind bereits seit den intensivierten Pogromen der ersten russischen Revolution von 1905 in Europa. Die Wanderungsstrukturen dieser verschiedenen und sehr heterogenen Gruppen von „Russen“ stehen im Mittelpunkt des Vortrags. [less ▲]

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See detailDiscussion of "Do ETFs Increase Liquidity?" by Mehmet Saglam, Tugkan Tuzun and Russ Wermers
Holcblat, Benjamin UL

Scientific Conference (2019, October 18)

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See detailRegards allemands sur le Luxembourg
Brüll, Christoph UL

Scientific Conference (2019, October 17)

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See detailRegards belges sur le Luxembourg 1919-1921
Brüll, Christoph UL

Scientific Conference (2019, October 17)

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See detailOral History Choices in the Digital Age: An International Perspective
Lambert, Douglas UL

Scientific Conference (2019, October 17)

Indexing oral histories digitally at the timecode level is a practice increasingly adopted for collections, often with the goal of creating online access to recordings. A particular attraction to using an ... [more ▼]

Indexing oral histories digitally at the timecode level is a practice increasingly adopted for collections, often with the goal of creating online access to recordings. A particular attraction to using an index is that it can be generated in less time than a transcript, especially when both must be done manually. Indexing provides convenient access to original recordings and can be a platform for decision-making about a collection over time, for researchers or collection stewards. In my current work in digital oral history at the University of Luxembourg’s Centre for Contemporary and Digital History (C2DH), indexing is being embraced for these strategic and practical benefits. However, indexing approaches I promoted previously in the US will need to be re-envisioned, retooled, and otherwise adapted for new and different cultural and technological contexts. In Europe, many oral history projects tend to be focused on journalistic-style research, so the goal of recording and indexing is different; curating, archiving, and publishing recordings is not necessarily expected or assumed. In Luxembourg and elsewhere in Europe, there is great interest in applying technology-centered analyses to oral history corpora (e.g., topic modeling, sentiment analysis, corpus linguistics, etc.), work predicated on high-quality transcripts rather than indexing. At the same time, improvements have been made in other technology/transcript-centered methods of analysis, such as keyword extraction, named entity recognition, and automated indexing—all of which could advance and improve oral history indexing and analysis practice. These new approaches will be more viable as speech recognition technology continues to improve, making transcripts easier and cheaper to create. As these factors converge, a new balance between transcription, indexing, and human interpretation will develop that supports both conventional oral history uses as well as secondary collection research activities. [less ▲]

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See detailApproche européenne sur l'entreprise : de la nouveauté ?
Corbisier, Isabelle UL

Scientific Conference (2019, October 17)

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See detailMonitoring du système scolaire – Le modèle luxembourgeois (invited talk)
Fischbach, Antoine UL

Scientific Conference (2019, October 17)

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See detailOuter and Anti Joins in Temporal-Probabilistic Databases
Papaioannou, Katerina; Theobald, Martin UL; Böhlen, Michael H.

in 35th IEEE International Conference on Data Engineering, ICDE 2019, Macao, China, April 8-11, 2019 (2019, October 16)

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See detailTravail frontalier en Suisse et au Luxembourg : mobilités, profils et défis
Pigeron-Piroth, Isabelle UL; Helfer, Malte UL; Belkacem, Rachid

Scientific Conference (2019, October 15)

La Suisse et le Luxembourg sont particulièrement concernés par le travail frontalier. Ces deux pays accueillent à eux seuls plus d’un demi-million de travailleurs frontaliers et recourent à la main ... [more ▼]

La Suisse et le Luxembourg sont particulièrement concernés par le travail frontalier. Ces deux pays accueillent à eux seuls plus d’un demi-million de travailleurs frontaliers et recourent à la main-d’œuvre frontalière depuis plusieurs décennies. Petits pays dynamiques ayant d’importants besoins de main-d’œuvre, ils se caractérisent par des différentiels liés à la présence de frontières (différentiels de prix immobiliers, de taux de chômage, de salaires, de niveaux d’activité économique … avec les pays voisins). Ces différentiels entretiennent la dynamique du travail frontalier (Belkacem et Pigeron-Piroth, 2016). [less ▲]

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See detailPerformance Modelling of V2V based Collective Perceptions in Connected and Autonomous Vehicles
Huang, Hui UL; Fang, Wenqi; Li, Huiyun

in 2019 IEEE 44th Conference on Local Computer Networks (LCN) (2019, October 14)

With the introduction of Connected and Autonomous Vehicles (CAVs), it is possible to extend the limited horizon of vehicles on the road by collective perceptions, where vehicles periodically share their ... [more ▼]

With the introduction of Connected and Autonomous Vehicles (CAVs), it is possible to extend the limited horizon of vehicles on the road by collective perceptions, where vehicles periodically share their sensory information with others using Vehide-2-Vehicle (V2V) communications. This technique relies on a certain number of participants to have a measurable advantage. Nevertheless, the spread of CAVs will take a considerable period of time, it is critical to understand the benefits and limits of V2V based collective perceptions in different market stages. In this work, we characterise the effective Field of View (eFoV) of a vehicle as the perception range using local sensors only, and the collective Field of View (cFoV) as the region learn from the network. Applying analytic and simulation studies in highway scenarios, we show that the eFoV drops quickly with the increase in traffic density due to blockage effects of surrounding vehicles, and it is insufficient to overcome this problem by increasing the sensing range of local sensors. On the other hand, vehicles can gain around 16 folds more information about the road environment by leveraging collective perceptions with only 10\% CAV penetration rate. When the penetration rate reaches to around 30\%, collective perceptions can provide 95\% coverage over the road environments. Our analyses also show that apart from the benefits, employing collective perceptions could result in heavy broadcast redundancy, hence wasting the already scarce network resources. This observation suggests that the sharing of sensory information should be controlled appropriately to avoid overloading the communication networks. [less ▲]

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See detailInside the Trading Zone: Doing Digital Hermeneutics in an Interdisciplinary Setting
van der Heijden, Tim UL; Tatarinov, Juliane UL

Scientific Conference (2019, October 11)

Our contribution examines the conference theme of digital hermeneutics from the perspective of the Doctoral Training Unit (DTU) in ‘Digital History and Hermeneutics’, a four-year interdisciplinary ... [more ▼]

Our contribution examines the conference theme of digital hermeneutics from the perspective of the Doctoral Training Unit (DTU) in ‘Digital History and Hermeneutics’, a four-year interdisciplinary research and training program hosted by the Centre for Contemporary and Digital History (C²DH) at the University of Luxembourg. The DTU is designed as an experimental platform for collaboration or ‘trading zone’, in which thirteen doctoral candidates with different disciplinary backgrounds – from history, linguistics and philosophy to computer and information science – study and reflect on the epistemological and methodological implications of the ‘digital turn’ on historical research. This presentation reflects on the project’s first year, in which the doctoral candidates were introduced to various skills and methods in digital humanities, including text mining, digital source criticism, database structures, data visualization, GIS analysis, tool criticism and algorithmic critique; and its second year, when data collections had been created and research tools identified that were going to be applied to it. By doing so, it presents some of the main practical and epistemological opportunities and challenges of “thinkering” with digital tools and technologies in the Digital History Lab of the C2DH, and it reflects scientific dissemination strategies for the group and the individual. The analysis is informed by studies on interdisciplinarity, digital humanities infrastructures and communities of practice. It furthermore draws on a series of semi-structured interviews and self-reflexive training reports, in which the doctoral candidates of the DTU reflect on their experiences in doing digital hermeneutics in an interdisciplinary setting. [less ▲]

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See detailDeep Learning Quality Control for High-Throughput High-Content Screening Microscopy Images
Garcia Santa Cruz, Beatriz UL; Jarazo, Javier UL; Schwamborn, Jens Christian UL et al

Poster (2019, October 10)

Automation of biological image analysis is essential to boost biomedical research. The study of complex diseases such as neurodegenerative diseases calls for big amounts of data to build models towards ... [more ▼]

Automation of biological image analysis is essential to boost biomedical research. The study of complex diseases such as neurodegenerative diseases calls for big amounts of data to build models towards precision medicine. Such data acquisition is feasible in the context of high-throughput high-content screening (HTHCS) in which the quality of the results relays on the accuracy of image analysis. Deep learning (DL) yields great performance in image analysis tasks especially with big amounts of data such as the produced in HTHCS contexts. Such DL and HTHCS strength is also their biggest weakness since DL solutions are highly sensitive to bad quality datasets. Hence, accurate Quality Control (QC) for microscopy HTHCS becomes an essential step to obtain reliable pipelines for HTHCS analysis. Usually, artifacts found on these platforms are the consequence of out-of-focus and undesirable density variations. The importance of accurate outlier detection becomes essential for both the training process of generic ML solutions (i.e. segmentation or classification) and the QC of the input data such solution will predict on. Moreover, during the QC of the input dataset, we aim not only to discard unsuitable images but to report the user on the quality of its dataset giving the user the choice to keep or discard the bad images. To build the QC solution we employed fluorescent microscopy images of rosella biosensor generated in the HTHCS platform. A total of 15 planes ranging from -6z to +7z steps to the two optimum planes. We evaluated 27 known focus measure operators and concluded that they have low sensitivity in noisy conditions. We propose a CNN solution which predicts the focus error based on the distance to the optimal plane, outperforming the evaluated focus operators. This QC allows for better results in cell segmentation models based on U-Net architecture as well as promising improvements in image classification tasks. [less ▲]

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See detailThe ESP estimator
Holcblat, Benjamin UL; Sowell, Fallaw

Scientific Conference (2019, October 08)

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See detailBig Automotive Data Preprocessing: A Three Stages Approach
Tawakuli, Amal UL; Kaiser, Daniel UL; Engel, Thomas UL

Poster (2019, October 08)

The automotive industry generates large datasets of various formats, uncertainties and frequencies. To exploit Automotive Big Data, the data needs to be connected, fused and preprocessed to quality ... [more ▼]

The automotive industry generates large datasets of various formats, uncertainties and frequencies. To exploit Automotive Big Data, the data needs to be connected, fused and preprocessed to quality datasets before being used for production and business processes. Data preprocessing tasks are typically expensive, tightly coupled with their intended AI algorithms and are done manually by domain experts. Hence there is a need to automate data preprocessing to seamlessly generate cleaner data. We intend to introduce a generic data preprocessing framework that handles vehicle-to-everything (V2X) data streams and dynamic updates. We intend to decentralize and automate data preprocessing by leveraging edge computing with the objective of progressively improving the quality of the dataflow within edge components (vehicles) and onto the cloud. [less ▲]

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See detailSoftwarization of SCADA: Lightweight Statistical SDN-Agents for Anomaly Detection
Rinaldi, Giulia UL; Adamsky, Florian UL; Soua, Ridha UL et al

in 10th International Conference on Networks of the Future (NoF) (2019, October 04)

The increasing connectivity of restricted areas suchas Critical Infrastructures (CIs) raises major security concernsfor Supervisory Control And Data Acquisition (SCADA) systems,which are deployed to ... [more ▼]

The increasing connectivity of restricted areas suchas Critical Infrastructures (CIs) raises major security concernsfor Supervisory Control And Data Acquisition (SCADA) systems,which are deployed to monitor their operation. Given the impor-tance of an early anomaly detection, Intrusion Detection Systems(IDSs) are introduced in SCADA systems to detect malicious ac-tivities as early as possible. Agents or probes form the cornerstoneof any IDS by capturing network packets and extracting relevantinformation. However, IDSs are facing unprecedented challengesdue to the escalation in the number, scale and diversity of attacks.Software-Defined Network (SDN) then comes into play and canprovide the required flexibility and scalability. Building on that,we introduce Traffic Agent Controllers (TACs) that monitor SDN-enabled switches via OpenFlow. By using lightweight statisticalmetrics such as Kullback-Leibler Divergence (KLD), we are ableto detect the slightest anomalies, such as stealth port scans, evenin the presence of background traffic. The obtained metrics canalso be used to locate the anomalies with precision over 90%inside a hierarchical network topology. [less ▲]

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See detailOptimized and flexible scheduling of AGVs and process machines in Re- manufacturing 4 .0 Systems using multi-agent technology and simultaneous scheduling
Groß, Sebastian UL; Gerke, Wolfgang; Plapper, Peter UL

in Ramírez Fernández, Francisco Javier; Honrubia Escribano, Andrés (Eds.) Abstracts III International Workshop on Autonomous Remanufacturing 2019 (2019, October 02)

In remanufacturing processes the condition of the used products is unknown. This leads to many challenges which are special to the domain of remanufacturing and not known from manufacturing. One of these ... [more ▼]

In remanufacturing processes the condition of the used products is unknown. This leads to many challenges which are special to the domain of remanufacturing and not known from manufacturing. One of these challenges is the stochastic routing of products based on the unknown product conditions. This problem in particular requires a flexible scheduling and control system for the remanufacturing system as well as the intralogistics. The aim of this research is to optimize the scheduling and control of remanufacturing systems considering the flexible material transport by AGVs. Therefore the networking of all resources is organized as an embedded system treating the remanufacturing system as a cyber-physical system in the context of industry 4.0. The scheduling and control of the remanufacturing system will be achieved by a combination of multi-agent technology to deal with unexpected events and the optimization of the schedule by simultaneous scheduling of machines and AGVs. Machine scheduling and transport scheduling have been vastly studied by many researchers, but most of the works address both problems separately. However, these two problems are closely linked and influence each other. By looking at them together, it is possible to achieve an improvement in the overall schedule. In the first step of the research work, the simultaneous scheduling of machines and AGVs has been compared with the currently used sequential scheduling within a simulation study. For this purpose, benchmark instances known in the literature were used. The simulation results show the superiority of the simultaneous scheduling of machines and AGVs. [less ▲]

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See detailP3LS : Plausible Deniability for Practical Privacy-Preserving Live Streaming
Decouchant, Jérémie UL; Boutet, Antoine; Yu, Jiangshan et al

Scientific Conference (2019, October)

Video consumption is one of the most popular Internet activities worldwide. The emergence of sharing videos directly recorded with smartphones raises important privacy concerns. In this paper we propose ... [more ▼]

Video consumption is one of the most popular Internet activities worldwide. The emergence of sharing videos directly recorded with smartphones raises important privacy concerns. In this paper we propose P3LS , the first practical privacy-preserving peer-to-peer live streaming system. To protect the privacy of its users, P3LS relies on k-anonymity when users subscribe to streams, and on plausible deniability for the dissemination of video streams. Specifically, plausible deniability during the dissemination phase ensures that an adversary is never able to distinguish a user’s stream of interest from the fake streams from a statistical analysis (i.e., using an analysis of variance). We exhaustively evaluate P3LS and show that adversaries are not able to identify the real stream of a user with very high confidence. Moreover, P3LS consumes 30% less bandwidth than the standard k-anonymity approach where nodes fully contribute to the dissemination of k streams. [less ▲]

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See detailSimultaneous State and False-Data Injection Attacks Reconstruction for NonLinear Systems: an LPV Approach
Bezzaoucha, Souad UL; Voos, Holger UL

in Bezzaoucha, Souad (Ed.) International Conference on Automation, Control and Robots (2019, October)

The present contribution addresses simultaneous state and actuator/sensor false-data injection attacks reconstruction for nonlinear systems. The considered actuator/sensor attacks are modeled as time ... [more ▼]

The present contribution addresses simultaneous state and actuator/sensor false-data injection attacks reconstruction for nonlinear systems. The considered actuator/sensor attacks are modeled as time-varying parameters with a multiplicative effect on the actuator input signal and the sensor output signal, respectively. Based on the sector non-linearity approach and the convex polytopic transformation, the nonlinear model is written in a Linear Parameter-Varying (LPV) form, then an observer allowing both state and attack reconstruction is designed by solving an LMI optimization problem. [less ▲]

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See detailSDN-based Pseudonym-Changing Strategy for Privacy Preservation in Vehicular Networks
Boualouache, Abdelwahab UL; Soua, Ridha UL; Engel, Thomas UL

in 15th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob'19) (2019, October)

The pseudonym-changing approach is the de-factolocation privacy solution proposed by security standards toensure that drivers are not tracked during their journey. SeveralPseudonym Changing Strategies ... [more ▼]

The pseudonym-changing approach is the de-factolocation privacy solution proposed by security standards toensure that drivers are not tracked during their journey. SeveralPseudonym Changing Strategies (PCSs) have been proposed tosynchronize Pseudonym Changing Processes (PCPs) between con-nected vehicles. However, most of the existing strategies are static,rigid and do not adapt to the vehicles’ context. In this paper, weexploit the Software Defined Network (SDN) paradigm to proposea context-aware pseudonym changing strategy (SDN-PCS) whereSDN controllers orchestrate the dynamic update of the securityparameters of the PCS. Simulation results demonstrate that SDN-PCS strategy outperforms typical static PCSs to perform efficientPCPs and protect the location privacy of vehicular network users [less ▲]

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See detailExploring the value of user-generated app data to design and improve urban running environments
van Renswouw, Loes; Bogers, Sander; Lallemand, Carine UL et al

Scientific Conference (2019, October)

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See detailL’UniGR-Center for Border Studies et ses outils d’analyse
Wille, Christian UL; Dethier, Perrine

Scientific Conference (2019, October)

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See detailOn the Event-based Attack-tolerant Control: A Polytopic Representation
Bezzaoucha, Souad UL; Voos, Holger UL

in Bezzaoucha, Souad (Ed.) International Conference on Automation, Control and Robots (2019, October)

In the present contribution, we present a new event-based control representation. Based on the polytopic approach, more specifically the sector nonlinear transformation, an event-based attack-tolerant ... [more ▼]

In the present contribution, we present a new event-based control representation. Based on the polytopic approach, more specifically the sector nonlinear transformation, an event-based attack-tolerant control, and scheduling co-design strategy are proposed. From the event triggering definition (sample-and-hold strategy), polytopic writing of the event-triggered feedback control is first presented and then incorporated into the system dynamics for analysis. Our goal is to present a unique model that is able to deal with the co-design problem simultaneously and that can be handled by classical control synthesis tools. The novel representation, including data deception and attack tolerant control is formulated as a BMI optimization problem ensuring both stability and some level performance requirements (L2 attenuation of the cyber-attack). [less ▲]

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See detailFlood Detection On Low Cost Orbital Hardware
Mateo-Garcia, Gonzalo; Oprea, Silviu; Smith, Lewis et al

Scientific Conference (2019, October)

Satellite imaging is a critical technology for monitoring and responding to natural disasters such as flooding. Despite the capabilities of modern satellites, there is still much to be desired from the ... [more ▼]

Satellite imaging is a critical technology for monitoring and responding to natural disasters such as flooding. Despite the capabilities of modern satellites, there is still much to be desired from the perspective of first response organisations like UNICEF. Two main challenges are rapid access to data, and the ability to automatically identify flooded regions in images. We describe a prototypical flood segmentation system, identifying cloud, water and land, that could be deployed on a constellation of small satellites, performing processing on board to reduce downlink bandwidth by 2 orders of magnitude. We target PhiSat-1, part of the FSSCAT mission, which is planned to be launched by the European Space Agency (ESA) near the start of 2020 as a proof of concept for this new technology. [less ▲]

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See detailDie Maske des Bösen : Lombroso, Fu-Manchu, Mabuse
Kohns, Oliver UL

Scientific Conference (2019, October)

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See detailUser Experience Design for E-Voting: How mental models align with security mechanisms
Zollinger, Marie-Laure UL; Distler, Verena UL; Roenne, Peter UL et al

in Electronic Voting (2019, October)

This paper presents a mobile application for vote-casting and vote-verification based on the Selene e-voting protocol and explains how it was developed and implemented using the User Experience Design ... [more ▼]

This paper presents a mobile application for vote-casting and vote-verification based on the Selene e-voting protocol and explains how it was developed and implemented using the User Experience Design process. The resulting interface was tested with 38 participants, and user experience data was collected via questionnaires and semi-structured interviews on user experience and perceived security. Results concerning the impact of displaying security mechanisms on UX were presented in a complementary paper. Here we expand on this analysis by studying the mental models revealed during the interviews and compare them with theoretical security notions. Finally, we propose a list of improvements for designs of future voting protocols. [less ▲]

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See detailHandling duplicates in Dockerfiles families: Learning from experts
Oumaziz, Mohamed; Falleri, Jean-Rémy; Blanc, Xavier et al

in 35th IEEE International Conference on Software Maintenance and Evolution (ICSME) (2019, October)

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See detailHouston We Have a Law. A Model for National Regulation of Space Resources Activities.
Salmeri, Antonino UL

in Proceedings of the 70th International Astronautical Congress 2018 (2019, October)

The field of space resources activities is rapidly maturing, but we still do not have a legal regime able to cope with such development. The United Nations Committee on the Peaceful Uses of Outer Space ... [more ▼]

The field of space resources activities is rapidly maturing, but we still do not have a legal regime able to cope with such development. The United Nations Committee on the Peaceful Uses of Outer Space finally started to debate whether commercialization of space resources is permitted under current international space law only in 2018, and yet declaring that space resources activities are lawful is barely the start. In fact, the real challenge is how to regulate them in light of the obligations set forth in international space law, without jeopardizing their economic convenience. The present paper addresses precisely this question by presenting a draft law redacted in articles, coupled with a comprehensive explanatory note. Inter alia, the paper introduces a new “space resources activities” license and proposes a detailed authorization regime based on the grant of priority rights limited in size, number and time extension. Based on the above, the paper concludes praising the importance of domestic regulation of space resources activities, when based on the same language and spirit of the OST and coordinated through mutual recognition. [less ▲]

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See detailEFFECTS OF MULTIPLE OSCILLATOR PHASE NOISE IN PRECODING PERFORMANCE
Martinez Marrero, Liz UL; Merlano Duncan, Juan Carlos UL; Querol, Jorge UL et al

Scientific Conference (2019, October)

Satellite Precoding is a promising technique to meet the target data rates of the future high throughput satellite systems and the costs per bit as required by 5G applications and networks, but it ... [more ▼]

Satellite Precoding is a promising technique to meet the target data rates of the future high throughput satellite systems and the costs per bit as required by 5G applications and networks, but it requires strict synchronization among the transmitted waveforms, in addition to accurate channel state information. Most of the published work about this topic consider ideal oscillators, but in practice, the output of an oscillator is not a single spectral line at the nominal frequency. This paper proposes a model for the oscillator phase noise and analyzes the resulting received signal to interference plus noise ratio (SNIR) in a satellite communication system using Precoding. Simulations of a communication satellite system with a two-beam transponder and two receivers were performed to compute the effective SNIR. This work uses a simulator which also considers practical impairments such as time misalignment, errors in the channel state information, interference, thermal noise and phase noise masks for satellite oscillators. The Precoding methods used for the analysis are Zero Forcing (ZF) and Minimum Mean Square Error (MMSE). The obtained results prove that there is a degradation in the performance due to the use of independent oscillators but this effect is compensated by the precoding matrix. [less ▲]

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See detailTrustworthiness in IoT - A Standards Gap Analysis on Security, Data Protection and Privacy
Samir Labib, Nader UL; Brust, Matthias R. UL; Danoy, Grégoire UL et al

in Samir Labib, Nader; Brust, Matthias R.; Danoy, Grégoire (Eds.) et al Trustworthiness in IoT - A Standards Gap Analysis on Security, Data Protection and Privacy (2019, October)

With the emergence of new digital trends like Internet of Things (IoT), more industry actors and technical committees pursue research in utilising such technologies as they promise a better and optimised ... [more ▼]

With the emergence of new digital trends like Internet of Things (IoT), more industry actors and technical committees pursue research in utilising such technologies as they promise a better and optimised management, improved energy efficiency and a better quality living through a wide array of value-added services. However, as sensing, actuation, communication and control become increasingly more sophisticated, such promising data-driven systems generate, process, and exchange larger amounts of security-critical and privacy-sensitive data, which makes them attractive targets of attacks. In turn this affirms the importance of trustworthiness in IoT and emphasises the need of a solid technical and regulatory foundation. The goal of this paper is to first introduce the concept of trustworthiness in IoT, its main pillars namely, security, privacy and data protection, and then analyse the state-of-the-art in research and standardisation for each of these subareas. Throughout the paper, we develop and refer to Unmanned Aerial Vehicles (UAVs) as a promising value-added service example of mobile IoT devices. The paper then presents a thorough gap analysis and concludes with recommendations for future work. [less ▲]

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See detailAuto-encoding Robot State against Sensor Spoofing Attacks
Rivera, Sean UL; Lagraa, Sofiane UL; Iannillo, Antonio Ken UL et al

in International Symposium on Software Reliability Engineering (2019, October)

In robotic systems, the physical world is highly coupled with cyberspace. New threats affect cyber-physical systems as they rely on several sensors to perform critical operations. The most sensitive ... [more ▼]

In robotic systems, the physical world is highly coupled with cyberspace. New threats affect cyber-physical systems as they rely on several sensors to perform critical operations. The most sensitive targets are their location systems, where spoofing attacks can force robots to behave incorrectly. In this paper, we propose a novel anomaly detection approach for sensor spoofing attacks, based on an auto-encoder architecture. After initial training, the detection algorithm works directly on the compressed data by computing the reconstruction errors. We focus on spoofing attacks on Light Detection and Ranging (LiDAR) systems. We tested our anomaly detection approach against several types of spoofing attacks comparing four different compression rates for the auto-encoder. Our approach has a 99% True Positive rate and a 10% False Negative rate for the 83% compression rate. However, a compression rate of 41% could handle almost all of the same attacks while using half the data. [less ▲]

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See detailWYLD Special Symposium: Technological Innovations in Dementia Diagnosis and Care
Leist, Anja UL

Scientific Conference (2019, October)

Researchers and entrepreneurs present technological innovations in dementia diagnosis and care, particularly through the use of wearables, apps, and novel data analysis techniques. These innovations ... [more ▼]

Researchers and entrepreneurs present technological innovations in dementia diagnosis and care, particularly through the use of wearables, apps, and novel data analysis techniques. These innovations address complex challenges of differential dementia diagnosis and ensuring high-quality and safe home and formal care. [less ▲]

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See detailGender inequalities across the life course: A societal perspective on gender differences in dementia
Leist, Anja UL; Ford, Katherine Joy UL

Scientific Conference (2019, October)

Introduction. Women are at increased risk of developing dementia, which can only partly be explained with differences in longevity, sex biology, or differences in detection/diagnosis. A promising approach ... [more ▼]

Introduction. Women are at increased risk of developing dementia, which can only partly be explained with differences in longevity, sex biology, or differences in detection/diagnosis. A promising approach at the population level is the systematic investigation of life course conditions for men and women across countries and cohorts in order to detect if schooling or work opportunities differ by gender. In the cognitive reserve framework, education and work reflect opportunities for cognitively stimulating activities, which increase cognitive reserve across the life course, and which could delay cognitive decline and the diagnosis of dementia. Method. We develop a framework for systematizing gender inequalities across different life stages and life domains, with a focus on systematic disadvantages for women that could be relevant barriers to cognitive reserve development. For the empirical analysis, we gather individual information and performance on cognitive tests from several harmonized cross-national aging surveys, i.e. the U.S. Health and Retirement Study and sister studies (SHARE, ELSA, SAGE), separated by cohort. Historical figures on gender inequalities for countries and cohorts, and their relevant timings in the life course of the older respondents, e.g. during schooling, were gathered from different sources, and merged with the individual-level data. Results. The new framework leads to testable hypotheses in both the Western and global context regarding life-course socialization and schooling and work opportunities that have been different for men and women. We will present preliminary evidence of how female (dis)advantages on different cognitive tests – memory, executive functioning – are mirroring societal gender inequalities. Discussion. We need to better understand how different life-course opportunities for men and women can create gender differences in dementia at old ages in order to identify individuals at risk today and improve conditions for future generations. [less ▲]

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See detailHow To Attract And Retain Talents In Not-For-Profit Organizations?
Usanova, Ksenia; Telitsina, Aleksandra; Geraudel, Mickaël UL

Scientific Conference (2019, September 30)

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See detailThree models of flexible talent management
Usanova, Ksenia; Geraudel, Mickaël UL; D'Armagnac, Sophie et al

Scientific Conference (2019, September 30)

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See detailAn industrial study on the differences between pre-release and post-release bugs
Rwemalika, Renaud UL; Kintis, Marinos; Papadakis, Mike UL et al

in Proceedings of 35th IEEE International Conference on Software Maintenance and Evolution (2019, September 30)

Software bugs constitute a frequent and common issue of software development. To deal with this problem, modern software development methodologies introduce dedicated quality assurance procedures. At the ... [more ▼]

Software bugs constitute a frequent and common issue of software development. To deal with this problem, modern software development methodologies introduce dedicated quality assurance procedures. At the same time researchers aim at developing techniques capable of supporting the early discovery and fix of bugs. One important factor that guides such research attempts is the characteristics of software bugs and bug fixes. In this paper, we present an industrial study on the characteristics and differences between pre-release bugs, i.e. bugs detected during software development, and post-release bugs, i.e. bugs that escaped to production. Understanding such differences is of paramount importance as it will improve our understanding on the testing and debugging support that practitioners require from the research community, on the validity of the assumptions of several research techniques, and, most importantly, on the reasons why bugs escape to production. To this end, we analyze 37 industrial projects from our industrial partner and document the differences between pre-release bugs and post-release bugs. Our findings suggest that post-release bugs are more complex to fix, requiring developers to modify several source code files, written in different programming languages, and configuration files, as well. We also find that approximately 82% of the post-release bugs involve code additions and can be characterized as "omission" bugs. Finally, we conclude the paper with a discussion on the implications of our study and provide guidance to future research directions. [less ▲]

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See detailThe Discovery of Ghijsbrecht Donckere’s Perpetuum Mobile: Visual Proof of the First Barometer?
Koeleman, Floor UL

Scientific Conference (2019, September 27)

Ghijsbrecht Donckere is sometimes associated with the invention of the barometer, based on two textual sources from about 1620. No visual record was known of Donckere’s instrument, which was referred to ... [more ▼]

Ghijsbrecht Donckere is sometimes associated with the invention of the barometer, based on two textual sources from about 1620. No visual record was known of Donckere’s instrument, which was referred to as a perpetuum mobile, until now. The rediscovery of a third source, and more importantly, the identification of his device on a contemporary painting, calls for a reassessment. The surroundings of the perpetual motion machine as represented in paint place this instrument at the intersection of natural philosophy and mechanical engineering. Donckere’s invention appears to be loosely based on Cornelis Drebbel’s perpetuum mobile (ca. 1607), and was commissioned by a courtly couple that was already partially informed about the hidden cause of motion of this machine. Nevertheless, the symbolic meaning of the object, rather than an understanding of its actual workings, is put on display. Donckere’s instrument is thus inextricably linked to one of the Aristotelian senses, and to concepts of astronomy and harmony, such as the primum mobile and musica universalis. Even though the textual evidence suggests that the device was at some point used to predict the weather, a reinterpretation particularly emphasizes the rhetoric of the time. The sources do not indicate that the effect of atmospheric pressure was already known. Taking these observations into account, the label of barometer does not seem applicable to Donckere’s perpetuum mobile. The newly revealed visual proof portrays the instrument instead as a collector’s item to be interpreted intellectually by an elite clientele in the early seventeenth century. [less ▲]

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See detailQualitative interviewing in multilingual research
Kalocsanyiova, Erika UL; Shatnawi, Malika

Scientific Conference (2019, September 27)

A growing body of research in super-diverse societies is conducted, by necessity, in multiple languages. Multilingual research practices can play a fundamental role in empowering participants and ... [more ▼]

A growing body of research in super-diverse societies is conducted, by necessity, in multiple languages. Multilingual research practices can play a fundamental role in empowering participants and privileging their voices, especially in migration-related studies. Yet, questions of cross-language interviewing are for the most part avoided or ignored in mainstream research. This contribution seeks to bring cross-language communication back into the focus of methodological discussions. Our paper builds on multilingual interview material extracted from a two-year linguistic ethnographic research project on forced migrants’ integration trajectories in Luxembourg. It looks at interpreter-mediated research encounters, as well as interviewees’ translation and translanguaging moves. Audio recordings and field notes from collaborative data analysis sessions underpin the data for this contribution. Our examples show that there is merit in fixing our analytical gaze on the minute details of language use across different codes, as these allow for a novel inquiry into specific moments of meaning making, role performances and rapport-building in qualitative interviewing. [less ▲]

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See detailThe impact of resilience on perceived chronic stress in undergraduate psychology students
Lenz, Hannah; Steffgen, Georges UL

Poster (2019, September 26)

The purpose of this exploratory study was to analyze the relationship between academic stressors and chronic stress in undergraduate psychology students, and to identify whether resilience and/or social ... [more ▼]

The purpose of this exploratory study was to analyze the relationship between academic stressors and chronic stress in undergraduate psychology students, and to identify whether resilience and/or social support function as mediators amid this relationship. Students from the University of Luxembourg and the University of Trier (N = 152) were recruited to fill out an online questionnaire consisting of the Trier inventory of chronic stress (Schulz et al., 2004), the resilience scale (Leppert et al., 2008), the perceived social support scale (Kliem et al., 2015), and five dimensions of academic stressors (Herbst et al., 2016). Results show a positive correlation between academic stressors and chronic stress. Multiple regression analysis prove that neither gender, home university, additional occupation nor social support are significant predictors of chronic stress. Compared to academic stressors and resilience, which account for more than 56% of the variance of students’ experienced chronic stress. Furthermore, academic stressors and chronic stress are mediated by resilience but not by perceived social support. The implications of the findings are discussed in terms of their relevance for the development of intervention programs against chronic stress of undergraduate students. [less ▲]

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See detailReal-time Radio Frequency Interference Detection and Mitigation with the Front-End GNSS Interference eXcisor (FENIX)
Querol Borras, Jorge UL; Perez, Adrian; Munoz-Martin, Joan Francesc et al

Scientific Conference (2019, September 26)

The number of applications based on Global Navigation Satellite Systems (GNSS) has been increasing in the last years. With its proliferation, Radio-Frequency Interference (RFI) has become one of the most ... [more ▼]

The number of applications based on Global Navigation Satellite Systems (GNSS) has been increasing in the last years. With its proliferation, Radio-Frequency Interference (RFI) has become one of the most concerning topics on GNSS-based devices for navigation, positioning and timing, but also for Earth Observation purposes such as GNSS-Reflectometry (GNSS-R) and GNSS-Radio Occultations (GNSS-RO) due to the corruption of the received signal and the corresponding geophysical measurements. The Front-End GNSS Interference eXcisor (FENIX) mitigates the problem of RFI by providing a plug-and-play solution which, placed between the antenna and the receiver, excises virtually any kind of interference signal, as its mitigation algorithm is agnostic on the particular type of RFI. The new version of FENIX is also capable of operating with large signal bandwidths ($\sim$50 MHz) and dual-band applications (e.g. L1 + L2 or L1/E1 + L5/E5). This paper shows the performance of the system for commercial GNSS receivers and GNSS-R applications. The use of FENIX in Microwave Radiometers is also possible, but it is out of the scope of this paper. [less ▲]

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See detailIncreasing DG Integration Level by Network Configuration Subset Analysis
Torchyan, Khachatur UL; Sachau, Juergen UL

in Proceedings of the International Conference on Smart Energy Systems and Technologies, SEST 2019 (2019, September 26)

With the increasing number of photovoltaic (PV) distributed generations (DG) being installed on the medium-voltage (MV) level and the fluctuations of the generation and loads, the supply security of the ... [more ▼]

With the increasing number of photovoltaic (PV) distributed generations (DG) being installed on the medium-voltage (MV) level and the fluctuations of the generation and loads, the supply security of the grid requires closer attention. Grid-wide voltage profile, overloading of substation transformers and overloading of lines may become bottlenecks for large-scale integration of PV plants. Here, measures to avoid cost-intensive network reinforcement are of interest. In this paper, analysis of grid reconfiguration and its impact on hosting capacity (HC) and grid operation are studied. Additionally, several PV control scenarios are considered according to current grid codes and grid code enhancement suggestions are made. The study is performed on a 43-bus 20 kV MV network model representative of Luxembourg's grid structure. The modeling, reconfiguration, HC calculation and analysis are done using Pandapower software. The results indicate that by proper reconfiguration of the network the HC can be increased approximately four times compared to the worst configuration and the grid code improvement can further increase the HC by another 15%, depending on the configuration. [less ▲]

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See detailPerformance Analysis of MANET Routing Protocols in Urban VANETs
Di Maio, Antonio UL; Palattella, Maria Rita UL; Engel, Thomas UL

in Lecture Notes in Computer Science (volume 11803) (2019, September 25)

Infrastructure-less communications between moving vehicles present emblematic challenges because of high node mobility and link volatility, which may harm the performances of different categories of ... [more ▼]

Infrastructure-less communications between moving vehicles present emblematic challenges because of high node mobility and link volatility, which may harm the performances of different categories of emerging vehicular applications. In order to move data between vehicles that are not in direct communication range, several distributed routing protocols have been proposed and tested in vehicular networks, highlighting their strengths and weaknesses. Some previous works report disagreeing claims about routing protocol performances in similar vehicular scenarios. Therefore, in this work, we evaluate the performances in terms of Packet Delivery Ratio (PDR), packet delay, frame collision rate, and signaling rate of three well-known routing protocols (AODV, DSDV, and GPSR), simulating them in a realistic Manhattan scenario. Furthermore, we evaluate the impact of typical urban obstacles (e.g. buildings) on the considered performance metrics. We observed that, in the proposed urban scenario, AODV provided the best PDR, GPSR the best packet delay, and DSDV failed to provide satisfactory performances due to signaling-induced congestion. Simulations showed that considering the shadowing effects induced by the buildings in an urban scenario drastically changes the observed performances, i.e. reduces the frame collisions, decreases the PDR, and increases the packet delay. [less ▲]

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See detailEvaluation von bauphysikalischen Vormessungen im Rahmen von komplexen Innendämmprojekten
Latz, Sebastian UL; Thewes, Andreas; Scholzen, Frank UL et al

in Vogel, Albert (Ed.) Bauphysiktage 2019 in Weimar - Bauphysik in Forschung und Praxis (2019, September 25)

The installation of internal insulation systems within the scope of refurbishment changes the hygrothermal behaviour of the existing masonry of a building in the long term. The internal insulation layer ... [more ▼]

The installation of internal insulation systems within the scope of refurbishment changes the hygrothermal behaviour of the existing masonry of a building in the long term. The internal insulation layer reduces the temperature of the masonry during the heating period and considerably reduces the drying potential. If the moisture content is too high due to the absorption of driving rain from the outside and moisture from the interior climate, the masonry may be permanently damaged and mould may form. The proof of function can be achieved by hygrothermal simulations. These simulations require the input of sensitive boundary conditions and different material parameters. In order to obtain precise simulation results, these input values should be validated by building physics measurements. In order to be able to better assess the simulation parameters, various physical measurements for the preparation of a field test for interior insulation systems in a conference room were carried out on behalf of the administration of the bâtiments publics at the University of Luxembourg as part of the research project "Possibilities and limitations of interior insulation in the renovation of public buildings in Luxembourg". [less ▲]

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See detailInbetriebnahme und Monitoring einer Feldtestfläche zur außenliegenden Lufttemperierung
Schmidt, Christoph Wilhelm UL; Altgeld, Horst; Groß, Bodo et al

in Völker, Conrad; Kornadt, Oliver; Jentsch, Mark (Eds.) et al Schriftenreihe der Professur Bauphysik, Bauphysiktage 2019 in Weimar - Bauphysik in Forschung und Praxis (2019, September 25)

Der Beitrag ist inhaltlich dem Forschungsprojekt „Low Exergy Utilisation - Einsatz von außen-liegender Wandtemperierung bei der Gebäudesanierung - Feldtest, CO2- Wärmepumpe mit Eisspeicher“ (kurz LEXU II ... [more ▼]

Der Beitrag ist inhaltlich dem Forschungsprojekt „Low Exergy Utilisation - Einsatz von außen-liegender Wandtemperierung bei der Gebäudesanierung - Feldtest, CO2- Wärmepumpe mit Eisspeicher“ (kurz LEXU II, Förderkennzeichen 0327370Y) zugeordnet. Im Rahmen des Pro-jektes wurde ein Großdemonstrator mit außenliegender Wand- und Lufttemperierung (kurz aWT & aLT) zusammen mit einem niederexergetischen Versorgungssystem, bestehend aus Eisspeicher, Wärmepumpe und PVT-Hybridkollektoren realisiert. Zur Heizperiode 2018/19 wurde die „Feldtestanlage“ in Betrieb genommen, sodass derzeit Messdaten generiert wer-den. In dem Forschungsprojekt wird der Demonstrator über eine Heizperiode und eine Kühl-periode messtechnisch begleitet und ausgewertet. Dabei wird der Großdemonstrator und alle Komponenten umfassend messtechnisch ausgewertet (~300 Messwerte). Ziel des Beitrags ist eine Darstellung der Grundlagen der außenliegenden Lufttemperierung, als niederexergetische und schnell regelbare Ergänzung zur außenliegenden Wandtemperie-rung. Bei der außenliegenden Lufttemperierung wird zwischen thermisch aktivierter Be-standswand und neuem Wärmedämm-Verbundsystem ein Luftspalt geschaffen, durch den Außenluft geführt und temperiert werden kann. Diese temperierte Außenluft wird dem dahin-terliegenden Raum (im Feldtest ein Büroraum mit rund 20 m² Grundfläche und zwei Arbeits-plätzen) als Frischluft zur Verfügung gestellt. Aufbauend auf den Grundlagen wird die Inbe-triebnahme der bereits umgesetzten Feldtestfläche mit möglichen Regelstrategien geschildert. Abschließend sollen erste Messergebnisse der Feldtestfläche dargestellt und diskutiert wer-den. Interessant sind hier vor allem (im Vergleich zur außenliegenden Wandtemperierung) die möglichen Zeitkonstanten und die erreichbaren Wärmeströme nach Innen (z.B. mögliche Wärmeübertragung als Kombination aus Konvektion im Luftspalt und Wärmeleitung durch die Bestandswand). Themengebiet: Energieeffiziente Gebäude & Bauphysik und Sanierung & Behaglichkeit und Raumklima [less ▲]

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See detailTHE MARKET SKEWNESS-RETURN RELATIONSHIP, Plenary Talk
Lehnert, Thorsten UL

Scientific Conference (2019, September 25)

Detailed reference viewed: 34 (4 UL)
See detailAuswertung eines Großdemonstrators mit außenliegender Wandtemperierung, Wärmepumpe, Eisspeicher und PTV-Hybridkollektoren
Schmidt, Christoph Wilhelm UL; Altgeld, Horst; Groß, Bodo et al

in Völker, Conrad; Kornadt, Oliver; Jentsch, Mark (Eds.) et al Schriftenreihe der Professur Bauphysik, Bauphysiktage 2019 in Weimar - Bauphysik in Forschung und Praxis (2019, September 25)

Der Beitrag ist inhaltlich dem Forschungsprojekt „Low Exergy Utilisation - Einsatz von außen-liegender Wandtemperierung bei der Gebäudesanierung - Feldtest, CO2- Wärmepumpe mit Eisspeicher“ (kurz LEXU II ... [more ▼]

Der Beitrag ist inhaltlich dem Forschungsprojekt „Low Exergy Utilisation - Einsatz von außen-liegender Wandtemperierung bei der Gebäudesanierung - Feldtest, CO2- Wärmepumpe mit Eisspeicher“ (kurz LEXU II, Förderkennzeichen 0327370Y) zugeordnet. Im Rahmen des Pro-jektes wurde ein Großdemonstrator mit außenliegender Wand- und Lufttemperierung (kurz aWT & aLT) zusammen mit einem niederexergetischen Versorgungssystem, bestehend aus Eisspeicher, Wärmepumpe und PVT-Hybridkollektoren realisiert. Zur Heizperiode 2018/19 wurde die „Feldtestanlage“ in Betrieb genommen, sodass derzeit Messdaten generiert wer-den. In dem Forschungsprojekt wird der Demonstrator über eine Heizperiode und eine Kühl-periode messtechnisch begleitet und ausgewertet. Dabei wird der Großdemonstrator und alle Komponenten umfassend messtechnisch ausgewertet (~300 Messwerte). Ziel des Beitrags ist eine Darstellung der messtechnischen Auswertung des Großdemonstra-tors über die aktuelle Heizperiode (2018/19) und die anstehende Kühlperiode (2019). Der Fo-kus der Auswertung liegt auf der Feldtestfassade der außenliegenden Wandtemperierung und adressiert die folgenden Fragestellungen: - Konnten die theoretischen Ergebnisse aus Berechnung und Simulation reproduziert werden? - Welche Heizleistungen sind über die außenliegende Wandtemperierung übertragbar? - Welches Fazit kann nach dem Betrieb der Anlage/Feldtestfläche über ca. ein Jahr ge-zogen werden? Je nach aktuellem Stand der begleitenden Simulations- und Potentialstudien können auch hier erste Ergebnisse präsentiert werden. Inhaltlich baut der Beitrag auf dem Beitrag „Außen-liegende Wand- und Lufttemperierung: Umsetzung eines Großdemonstrators“ von den Bau-physiktagen 2017 in Kaiserslautern auf. Im Anschluss an die dort beschriebene Umsetzung soll nun ein Fazit bzgl. Umsetzung, Monitoring und Simulation gezogen werden. [less ▲]

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See detail‘Bis zum Anthropozän und noch viel weiter’: Space Mining in Luxemburger Hörspielen
Thiltges, Sébastian UL

Scientific Conference (2019, September 25)

Detailed reference viewed: 9 (1 UL)
See detailMoney Laundering and Cryptocurrencies
Allegrezza, Silvia UL

Scientific Conference (2019, September 24)

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See detailEarly-stage topological and technological choices for TSN-based communication architectures
Navet, Nicolas UL; Villanueva, Josetxo; Migge, Jörn

Scientific Conference (2019, September 24)

A main issue in the design of automotive communication architectures is that the most important design choices pertaining to the topology of the networks and the technologies to use (protocols, data rate ... [more ▼]

A main issue in the design of automotive communication architectures is that the most important design choices pertaining to the topology of the networks and the technologies to use (protocols, data rate, hardware) have to be made at a time when the communication requirements are not entirely known. Indeed, many functions only becomes available along the development cycle, and vehicle platforms have to support incremental evolutions of the embedded system that may not be fully foreseeable at the time design choices are made. The problem is becoming even more difficult and crucial with the introduction of dynamically evolving communication requirements requiring network re-configuration at run-time. We present how the use of synthetic data, that is data generated programmatically based on past vehicle projects and what can be foreseen for the current project, enables the designers to make such early stage choices based on quantified metrics. The proposals are applied to Groupe Renault's FACE service-oriented E/E architecture with the use of a software-implemented function we called “Topology Stress Test”. [less ▲]

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See detailProceedings of the Deduktionstreffen 2019
Schon, Claudia; Steen, Alexander UL

Scientific Conference (2019, September 23)

The annual meeting Deduktionstreffen is the prime activity of the Special Interest Group on Deduction Systems (FG DedSys) of the AI Section of the German Society for Informatics (GI-FBKI). It is a meeting ... [more ▼]

The annual meeting Deduktionstreffen is the prime activity of the Special Interest Group on Deduction Systems (FG DedSys) of the AI Section of the German Society for Informatics (GI-FBKI). It is a meeting with a familiar, friendly atmosphere, where everyone interested in deduction can report on their work in an informal setting. [less ▲]

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See detailBreaking Unlinkability of the ICAO 9303 Standard for e-Passports using Bisimilarity
Horne, Ross James UL; Mauw, Sjouke UL; Smith, Zachary Daniel UL et al

in Breaking Unlinkability of the ICAO 9303 Standard for e-Passports using Bisimilarity (2019, September 23)

We clear up confusion surrounding privacy claims about the ICAO 9303 standard for e-passports. The ICAO 9303 standard includes a Basic Access Control (BAC) protocol that should protect the user from being ... [more ▼]

We clear up confusion surrounding privacy claims about the ICAO 9303 standard for e-passports. The ICAO 9303 standard includes a Basic Access Control (BAC) protocol that should protect the user from being traced from one session to another. While it is well known that there are attacks on BAC, allowing an attacker to link multiple uses of the same passport, due to differences in implementation; there still remains confusion about whether there is an attack on unlinkability directly on the BAC protocol as specified in the ICAO 9303 standard. This paper clarifies the nature of the debate, and sources of potential confusion. We demonstrate that the original privacy claims made are flawed, by uncovering attacks on a strong formulation of unlinkability. We explain why the use of the bisimilarity equivalence technique is essential for uncovering our attacks. We also clarify what assumptions lead to proofs of formulations of unlinkability using weaker notions of equivalence. Furthermore, we propose a fix for BAC within the scope of the standard, and prove that it is correct, again using a state-of-the-art approach to bisimilarity. [less ▲]

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See detailMulti-flow congestion-aware routing in software-defined vehicular networks
Di Maio, Antonio UL; Palattella, Maria Rita UL; Engel, Thomas UL

in 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall) Proceedings (2019, September 22)

5G-enabled vehicular networks will soon allow their users to exchange safety and non-safety related information over heterogeneous communication interfaces. Routing vehicular data flows over multi-hop ... [more ▼]

5G-enabled vehicular networks will soon allow their users to exchange safety and non-safety related information over heterogeneous communication interfaces. Routing vehicular data flows over multi-hop Vehicle-to-Vehicle (V2V) communications is one of the hardest challenges in vehicular networking, and it has been tackled in literature by using distributed algorithms. The distributed approach has shown significant inefficiencies in such dynamic vehicular scenarios, mainly due to poor network congestion control. To overcome the complexity of the envisioned architecture, and the inefficiency of distributed routing algorithms, we hereby propose to leverage the coordination capabilities of Software-Defined Networking (SDN) to determine optimal V2V multi-hop paths and to offload traffic from the Vehicle-to-Infrastructure-to-Vehicle (V2I2V) to the V2V communications, using both cellular and Wi-Fi technologies. In order to achieve this goal, we propose Multi-Flow Congestion-Aware Routing (MFCAR), a centralized routing algorithm that relies on graph theory to choose short and uncongested V2V paths. Realistic simulations prove that MFCAR outperforms well- established centralized routing algorithms (e.g. Dijkstra's) in terms of Packet Delivery Ratio (PDR), goodput and average packet delay, up to a five-fold performance gain. [less ▲]

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See detailBODYFITR: Robust Automatic 3D Human Body Fitting
Saint, Alexandre Fabian A UL; Shabayek, Abd El Rahman UL; Cherenkova, Kseniya UL et al

in Proceedings of the 2019 IEEE International Conference on Image Processing (ICIP) (2019, September 22)

This paper proposes BODYFITR, a fully automatic method to fit a human body model to static 3D scans with complex poses. Automatic and reliable 3D human body fitting is necessary for many applications ... [more ▼]

This paper proposes BODYFITR, a fully automatic method to fit a human body model to static 3D scans with complex poses. Automatic and reliable 3D human body fitting is necessary for many applications related to healthcare, digital ergonomics, avatar creation and security, especially in industrial contexts for large-scale product design. Existing works either make prior assumptions on the pose, require manual annotation of the data or have difficulty handling complex poses. This work addresses these limitations by providing a novel automatic fitting pipeline with carefully integrated building blocks designed for a systematic and robust approach. It is validated on the 3DBodyTex dataset, with hundreds of high-quality 3D body scans, and shown to outperform prior works in static body pose and shape estimation, qualitatively and quantitatively. The method is also applied to the creation of realistic 3D avatars from the high-quality texture scans of 3DBodyTex, further demonstrating its capabilities. [less ▲]

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See detail(Im)mobilizing languages
Kalocsanyiova, Erika UL

Scientific Conference (2019, September 19)

This presentation is concerned with the impact of multilingualism on forced migrants’ trajectories. It reports the findings of a two-year qualitative research project, which used ethnographic research ... [more ▼]

This presentation is concerned with the impact of multilingualism on forced migrants’ trajectories. It reports the findings of a two-year qualitative research project, which used ethnographic research methods, including narrative and go-along interviews, classroom and participant observations and linguistic analysis of interactional data. The project set out to investigate how forced migrants reflect, position, and affirm themselves – through languages – in multilingual societies. Our contribution aligns itself with the body of research that challenges hegemonic monolingual and monocultural practices (Grzymala-Kazlowska/Phillimore 2018, Van Avermaet 2009). Other major influences were Juffermans and Tavares’s (2017) research on south-north trajectories and linguistic repertoires, Stevenson’s (2014, 2017) work on language (hi)stories and Busch’s (2017) biographical explorations of Spracherleben. In this talk, the focus will be on the experiences of three men from Syria and Iraq who have obtained humanitarian protection in Luxembourg, but aspire to fulfil their integration aspirations across multiple locations and countries. A careful analysis of divergent trajectories sheds light on how experiences of linguistic inequality and/or success are imprinted on forced migrants’ repertoires and shape their understanding of (successful) integration. [less ▲]

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See detailWann kam die Grenze auf die Karte? Zur Konstruktion von Herrschaftsgebieten zwischen Reich und Frankreich in der Frühen Neuzeit
Uhrmacher, Martin UL

Scientific Conference (2019, September 19)

Feste politische Grenzen, wie man sie heute kennt, die ein Staatsgebiet nach innen wie nach außen umfassend begrenzen, sind im Raum zwischen Maas und Rhein ein Produkt des späten 18. Jahrhunderts. Für ... [more ▼]

Feste politische Grenzen, wie man sie heute kennt, die ein Staatsgebiet nach innen wie nach außen umfassend begrenzen, sind im Raum zwischen Maas und Rhein ein Produkt des späten 18. Jahrhunderts. Für diese Region wird nach dem Ursprung dieser festen Grenzlinien gesucht, die heute ein selbstverständlicher Bestandteil von Karten sind. Seit dem späten 16. Jahrhundert wurden im Westen des Heiligen Römischen Reiches erstmals historische Karten publiziert und im Druck verbreitet, die unser Bild der territorialen Landschaft bis heute prägen. Ab wann aber werden solche Grenzlinien zur Darstellung territorial-räumlicher Verhältnisse verwendet? Und welche Rolle kommt ihnen bei der Konstruktion von Herrschaft im Raum zu? Diesen Fragen widmet sich der Beitrag für die Region zwischen Maas und Rhein. Sie liegt an der Schnittstelle von Germania und Romania und ist durch Einflüsse beiderseits der Sprachgrenze geprägt. [less ▲]

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See detailSize-dependent spatial magnetization profile of Manganese-Zinc ferrite nanoparticles
Bersweiler, Mathias UL

Scientific Conference (2019, September 18)

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See detailInvestigation of the moment redistribution for steel concrete continuous beams
Yolacan, Taygun Firat UL; Schäfer, Markus UL

in The 14th Nordic Steel Construction Conference (2019, September 18)

This study investigates moment redistribution phenomenon for pin ended double-span steel-concrete continuous composite beams and arise a question about moment redistribution for the continuous beams ... [more ▼]

This study investigates moment redistribution phenomenon for pin ended double-span steel-concrete continuous composite beams and arise a question about moment redistribution for the continuous beams subjected to partially distributed or concentrated loading conditions. The overall objective of the study is to propose a methodology to fulfil the technical gaps adopted by Eurocode-4, which considers the redistribution for only uniformly load condition. A robust iterative algorithm is developed to obtain moment-curvature relations of the standard composite cross-sections. Flexural stiffness-curvature relations of the cross-sections are predicted through the moment-curvature relations. Flexural stiffness distribution along the composite beams is determined with curvature compatibility. Fourth order differential load-deflection equation is evaluated with finite difference solution scheme for continuous beam conditions and variable flexural stiffness along the beam length. A non-iterative incremental load-deflection algorithm is developed to calculate moment distribution in continuous beams with variable flexural stiffness. A benchmark example is solved with Eurocode- 4 provisions to validate the developed algorithms. Moment redistribution from hogging (negative) zone to sagging (positive) zone of uniformly loaded double-span continuous composite beam is illustrated considering the degree of flexural stiffness degradation in the composite medium. A question is arisen for moment redistribution in the continuous beams subjected to partially distributed or concentrated loading conditions. [less ▲]

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See detailImpact of reinforcement to moment resistance of composite slabs
Zhang, Qingjie UL; Schäfer, Markus UL; Kurz, Wolfgang

in The 2019 World Congress on Advances in Structural Engineering and Mechanics (ASEM19) (2019, September 17)

Composite slabs lead to slim and economic structural solutions with a low selfweight. The determination of their moment resistance follows the regulations presented in EN 1994-1-1 (2004) which are based ... [more ▼]

Composite slabs lead to slim and economic structural solutions with a low selfweight. The determination of their moment resistance follows the regulations presented in EN 1994-1-1 (2004) which are based on plastic design methods. The current version of Eurocode 4 does not consider explicitly additional reinforcement in the ribs for sagging moment resistance. However, the construction industry requires this possibility in order to provide economical and flexible design. Regarding this situation, further investigations are necessary to prove the applicability of plastic design methods. In the case of high bottom reinforcement ratio, a deep position of the plastic neutral axis occurs, and concrete compression failure may happen before most parts of the profiled steel sheeting and reinforcement yield. This leads to an overestimation of the bending resistance according to the plastic design method. A parametric study, based on approximately 290.000 different combinations of various cross-section geometries and materials, is provided to compare the plastic moment resistance with the resistance determined by strain-limited design. The results show that limitations are necessary to be enabled for the general application of plastic design methods. [less ▲]

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See detailThe real problem with Rawlsian reasonableness
Burks, Deven UL

Scientific Conference (2019, September 17)

In The Law of Peoples, Rawls states that, if “political liberalism offers no way of proving that this specification [of reasonableness] is itself reasonable”, this is no great loss, for “it is simply ... [more ▼]

In The Law of Peoples, Rawls states that, if “political liberalism offers no way of proving that this specification [of reasonableness] is itself reasonable”, this is no great loss, for “it is simply politically reasonable to offer fair terms of cooperation to other free and equal citizens, and it is simply politically unreasonable to refuse to do so” (Rawls 1999: 87-8). While Rawls is undoubtedly right that public reason liberalism analytically requires some standard of reasonableness, it is less obvious this standard must take Rawls’s preferred form. Yet criticisms of Rawlsian “reasonableness” as “loaded” (Stout 2004: 184), “chimerical” (Young 2005: 308) or “entirely circular” (Mulhall and Swift 2003: 483) often equivocate on the meaning of reasonableness and so fall afoul of the “equivocation defense” (Freeman 2004: 2063-5). In this paper, I improve on those earlier criticisms by means of a narrow, immanent criticism whereon the two basic aspects of reasonableness – (A1) proposing and abiding by fair terms of cooperation and (A2) recognizing the “burdens of judgment” (Rawls 1996: 54-8) – may plausibly conflict: in some instances, accepting (A2) may give persons reason to disagree over the need to accept (A1). To show this, I first restate two aspects of reasonableness as a biconditional: a person is reasonable iff (A1) and (A2) obtain. I then examine whether Rawls’s burdens give reason to doubt the requirement in (A1). Insofar as the third, fourth and fifth burdens give reason to doubt just this requirement, I conclude that Rawlsian reasonableness should be reformulated. This reformulation preserves what Rawls gets right about reasonableness – namely, the burdens – but replaces the old standard with “reasonableness pluralism”, from which it follows that public reason cannot represent all the necessary conditions of political justification under circumstances of reasonable pluralism. [less ▲]

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See detailLe blanchiment: évolution du cadre européen et nouvelles formes numériques
Allegrezza, Silvia UL

Scientific Conference (2019, September 17)

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See detailMale vs female gamers: Testing the stereotype threat effect in video gaming
Holl, Elisabeth UL; Wagener, Gary Lee; Melzer, André UL

Scientific Conference (2019, September 17)

Stereotype threat (ST), defined as the risk of confirming a negative stereotype about one’s own group, has been demonstrated in various social contexts. Regarding video games, for example, informing ... [more ▼]

Stereotype threat (ST), defined as the risk of confirming a negative stereotype about one’s own group, has been demonstrated in various social contexts. Regarding video games, for example, informing female participants that men would outperform women in gaming leads to gender differences in performance. To date, however, these studies have not looked into the mechanisms of this ST effect in gaming. In two lab studies (N=186), some participants were confronted with ST-related information before playing a video game. In Study 1, half of the participants read a bogus article confirming the “standard” gender stereotype (“men outperform women”). In Study 2, a reverse stereotype was presented to half of the participants (“women have outpaced men in some game genres”). In contrast to hypotheses, both studies failed to show the expected significant interaction effect of gender and ST condition on performance, although female participants confronted with the “standard” gender stereotype reported greater frustration in Study 1, for example. In sum, results indicate a complex relationship between gender, social identity, experience with the game genre, and behavior. Identifying oneself as a gamer and being experienced in a particular game genre were found to be better performance predictors than reading stereotype threatening information. [less ▲]

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See detailPhysical activity of children and adolescents in Luxembourg during school, physical education and leisure time: An accelerometry-based study
Eckelt, Melanie UL; Bund, Andreas UL; Hutmacher, Djenna UL et al

Poster (2019, September 13)

Objectives: Due to its great importance for development and health, the physical activity (PA) of children has become a key issue in research over the last decade. Simultaneously, the measurement of PA ... [more ▼]

Objectives: Due to its great importance for development and health, the physical activity (PA) of children has become a key issue in research over the last decade. Simultaneously, the measurement of PA has been strongly improved through the development of user-friendly and reliably working accelerometer, which allow to track PA over several consecutive days in an objective way. Although the benefits of accelerometry are well documented also for children (e.g. Hager et al., 2015), especially cross-national studies such as the Health Behaviour in School-aged Children (HBSC) are still using questionnaires and are focused only on overall or leisure time PA. This study as part of the PALUX project (Physical Activity of Children and Youth in Luxembourg) aims to (1) measure children's daily PA patterns using up-to-date accelerometers while (2) differentiating between PA in school, physical education and leisure time. Methods: In total, 242 children and adolescents (134 girls and 108 boys) aged from 10-18 years from 9 different schools in Luxembourg wore the ActiGraph GT3X-BT- accelerometer at the hip for a period of seven consecutive days. Total time in moderate-to-vigorous PA (MVPA) was calculated using the cut-of points from Evenson et al. (2008). Time spent in school and physical education were determined based on timetables provided by the schools. Results: Mean overall MVPA of participants over seven consecutive days was 307.6 min, with 98.4 min (32 %) during school time and 190.7 min (62 %) during leisure time. Only 16.7 min (6 %) of the school time MVPA were performed in physical education. Boys had more overall MVPA than girls (367.9 vs. 258.9 min, t(240) = 6.76, p < .01) due to significant differences in all areas considered here (schooltime: t(215) = 6.26, p < .01; leisure time: t(215) = 6.18, p < .01; physical education: t(188) = 3.07, p < .01). Children spent 25.6 min of an average physical education class of 77 min in MVPA, which is 19.71 % and thus much less than the 50 % recommended by the U.S. Department for Health and Human Sciences. Only 0.5% of the participants (1.2% of the boys and 0% of the girls) achieved this value. Discussion: Overall, 25.6 % of the children and adolescents in Luxembourg met WHO's PA guideline of at least 60 min MVPA per day, which is in line with results from other European countries. According to our data, the achieved MVPA is mainly due to leisure time activities, whereas the potential of school and physical education in providing and promoting PA has apparently not been fully exploited yet. The consistency of these findings will be examined in a second survey in 2019 [less ▲]

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See detailDifferences in physical activity among children with physically active and inactive parents
Eckelt, Melanie UL; Hutmacher, Djenna UL; Steffgen, Georges UL et al

Scientific Conference (2019, September 13)

Objectives: Parental physical activity is considered as positively related to children´s physical activity (PA; Sallis, Prochaska & Taylor, 2000). Since parents serve as role models, have the potential to ... [more ▼]

Objectives: Parental physical activity is considered as positively related to children´s physical activity (PA; Sallis, Prochaska & Taylor, 2000). Since parents serve as role models, have the potential to influence the health-related behavior and, for instance, to alter a mainly sedentary lifestyle of their children (Beets, Cardinal & Alderman, 2010), the impact of parental PA has become a key issue in research. Many studies report associations between parental PA and the PA behavior of their children, e.g., the direct involvement of the parents in activities with their children is related to increased levels of their PA (Adkins, Sherwood, Story, & Davis, 2004; Beets, Vogel, Chapman, Pitetti, & Cardinal, 2007). However, the mechanisms of parental influence are still poorly understood and besides recent studies are based on self-reported data. Therefore, this study aims to examine if parental PA is related to the subjectively and objectively measured PA of their children. Methods: 237 Luxembourgish children and adolescents (134 girls and 103 boys) aged from 10-18 years participated in the study. Via a digital questionnaire, the children indicated if their mother and father are physically active on a regular basis and if they are active together with their parents. Furthermore, the children and adolescents indicated if they are active at least 60 minutes/ day and if they own a membership in a sports club (MoMo physical activity questionnaire). Additionally, children’s PA behavior was objectively assessed by wearing an accelerometer (ActiGraph GT3X-BT) for a period of seven consecutive days. Activity was categorized as sedentary, light physical activity or moderate to vigorous physical activity (MVPA) using age-specific thresholds. Results: A multivariate ANOVA revealed significant differences in self-reported physical activity if the mother was physically active (F (2, 166) = 5.4, p < .01). Thus, children reported subjectively higher daily activity duration (p < .05) and more activities in a regular week (p < .01). There was no impact on self-reported PA if the father was active or the children were active with their parents together. Regarding the objective data, there were no significant differences between children with active parents and children with inactive parents. If the parents were active with their children together there were significant differences (F (3, 229) = 3.2, p < .05), thus MVPA per day was higher (p < .05) and the sedentary time was lower (p < .01). Neither subjective nor objective data revealed gender-specific differences. Discussion: In contrast to other studies, only the mother seems to have an influence on the subjective PA behavior of the children. The fact, that parents being active or in a sports club does not appear to enhance the PA of the children objectively. However, the objective PA is merely affected by being active together. According to this finding, joint activities of parents and children seem to be necessary to promote children’s PA effectively. It is important to note that in our study the parental PA was rated by the children. In future studies, parents should be included via self-report questionnaires and/or accelerometer. [less ▲]

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See detailSocial stratification in higher education trajectories: A sequence-analytical approach
Haas, Christina UL

Scientific Conference (2019, September 13)

Detailed reference viewed: 57 (2 UL)