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See detailA Novel Heap-based Pilot Assignment for Full Duplex Cell-Free Massive MIMO with Zero-Forcing
Nguyen, Van Hieu; Nguyen, van Dinh UL; Dobre, Octavia A. et al

in IEEE Journal Selected Areas in Communications (2020, June 07)

This paper investigates the combined benefits of full-duplex (FD) and cell-free massive multiple-input multipleoutput (CF-mMIMO), where a large number of distributed access points (APs) having FD ... [more ▼]

This paper investigates the combined benefits of full-duplex (FD) and cell-free massive multiple-input multipleoutput (CF-mMIMO), where a large number of distributed access points (APs) having FD capability simultaneously serve numerous uplink and downlink user equipments (UEs) on the same time-frequency resources. To enable the incorporation of FD technology in CF-mMIMO systems, we propose a novel heapbased pilot assignment algorithm, which not only can mitigate the effects of pilot contamination but also reduce the involved computational complexity. Then, we formulate a robust design problem for spectral efficiency (SE) maximization in which the power control and AP-UE association are jointly optimized, resulting in a difficult mixed-integer nonconvex programming. To solve this problem, we derive a more tractable problem before developing a very simple iterative algorithm based on inner approximation method with polynomial computational complexity. Numerical results show that our proposed methods with realistic parameters significantly outperform the existing approaches in terms of the quality of channel estimate and SE. [less ▲]

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See detailEnhancing CoAP Group Communication to Support mMTC Over Satellite Networks
Soua, Ridha UL; Palattella, Maria Rita UL; Stemper, André UL et al

in IEEE International Conference on Communications (ICC) (2020, June)

Massive MTC (mMTC) is one of the application scenarios that upcoming 5G networks are expected to support. Satellites come into play in mMTC to complement and extend terrestrial networks in under-served ... [more ▼]

Massive MTC (mMTC) is one of the application scenarios that upcoming 5G networks are expected to support. Satellites come into play in mMTC to complement and extend terrestrial networks in under-served areas, where several services can benefit from the adoption of a group communication model. The IETF has specifically standardized the usage of CoAP group communication. However, CoAP responses are still sent in unicast from each single CoAP server to the CoAP client, which results in a substantial traffic load. Such problem becomes more severe in integrated IoT-Satellite networks given the limited bandwidth of the satellite return channel and the large number of IoT devices in a mMTC scenario. To reduce network traffic overhead in group communication and improve the network responsiveness, this paper proposes an aggregation scheme for the CoAP group communication in combination with Observer pattern and proxying. Results obtained by using the openSAND emulator and CoAPthon library corroborate the merit of our optimization in terms of overhead reduction and delay. [less ▲]

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See detailSuccessive Convex Approximation for Transmit Power Minimization in SWIPT-Multicast Systems
Gautam, Sumit UL; Lagunas, Eva UL; Kisseleff, Steven UL et al

Scientific Conference (2020, June)

We propose a novel technique for total transmit power minimization and optimal precoder design in wireless multi-group (MG) multicasting (MC) systems. The considered framework consists of three different ... [more ▼]

We propose a novel technique for total transmit power minimization and optimal precoder design in wireless multi-group (MG) multicasting (MC) systems. The considered framework consists of three different systems capable of handling heterogeneous user types viz., information decoding (ID) specific users with conventional receiver architectures, energy harvesting (EH) only users with non-linear EH module, and users with joint ID and EH capabilities having separate units for the two operations, respectively. Each user is categorized under unique group(s), which can be of MC type specifically meant for ID users, and/or an energy group consisting of EH explicit users. The joint ID and EH users are a part of the (last) EH group as well as any one of the MC groups distinctly. In this regard, we formulate an optimization problem to minimize the total transmit power with optimal precoder designs for the three aforementioned scenarios, under constraints on minimum signal-to-interference-plus-noise ratio and harvested energy by the users with respective demands. The problem may be adapted to the well-known semi-definite program, which can be typically solved via relaxation of rank-1 constraint. However, the relaxation of this constraint may in some cases lead to performance degradation, which increases with the rank of the solution obtained from the relaxed problem. Hence, we develop a novel technique motivated by the feasible-point pursuit and successive convex approximation method in order to address the rank-related issue. The benefits of the proposed method are illustrated under various operating conditions and parameter values, with comparison between the three above-mentioned scenarios. [less ▲]

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See detailLes exceptions à la règle de l’Etat de droit: déroger aux droits fondamentaux en période de crise?Cahiers Jean Monnet, Actes des ateliers doctoraux « L’état de droit », Centre d'Excellence Europe Capitole
Mavrouli, Roila UL

in Cahiers Jean Monnet, Actes des ateliers doctoraux « L’état de droit », Centre d'Excellence Europe Capitole (2020)

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See detailPractical Posterior Error Bounds from Variational Objectives
Huggins, Jonathan; Kasprzak, Mikolaj UL; Campbell, Trevor et al

in Proceedings of the 23rd International Conference on Artificial Intelligence and Statistics (AISTATS) (2020, June)

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See detailEthnocentric preferences and the environment with international trade
Zanaj, Skerdilajda UL

E-print/Working paper (2020)

We define a model of international trade with two countries, two vertically differentiated goods, and heterogenous consumers concerning their willingness to pay for quality. Trade generates two sources of ... [more ▼]

We define a model of international trade with two countries, two vertically differentiated goods, and heterogenous consumers concerning their willingness to pay for quality. Trade generates two sources of pollution: the production of domestic and traded goods, and their transportation between countries. Consumers in both countries manifest home bias which translates into ethnocentric preferences: (i) consumer perceive the quality of the domestic good amplified; and (ii) consumers thrive additional satisfaction when consuming a domestic good rather than a foreign one since only the former can satisfy their sense of place. By contrast, they suffer a psychological penalty when consuming a foreign product. We investigate the role of trade costs and ethnocentric attitude in shaping the equilibrium configuration of the international duopoly. Finally, we uncover the environmental damage from production and from transport in presence of ethnocentrism. [less ▲]

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See detailΤο Επιλεκτικό Πλεονέκτημα
Pantazatou, Aikaterini UL; Rodopoulos, Michail

in Christianos, Vasileios; Rodopoulos, Michail (Eds.) Δίκαιο Κρατικών Ενισχύσεων (2020)

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See detailΕυρωπαϊκά Διαρθρωτικά Ταμεία και κρατικές ενισχύσεις
Pantazatou, Aikaterini UL

in Christianos, Vasileios; Rodopoulos, Michail (Eds.) Δίκαιο Κρατικών Ενισχύσεων (2020)

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See detailBoosting SWIPT via Symbol-Level Precoding
Gautam, Sumit UL; Krivochiza, Jevgenij UL; Haqiqatnejad, Alireza UL et al

Scientific Conference (2020, May 29)

In this paper, we investigate a simultaneous wireless information and power transmission (SWIPT) system, wherein a single multi-antenna transmitter serves multiple single-antenna users which employ the ... [more ▼]

In this paper, we investigate a simultaneous wireless information and power transmission (SWIPT) system, wherein a single multi-antenna transmitter serves multiple single-antenna users which employ the power-splitting (PS) receiver architecture. We formulate a Symbol-Level Precoding (SLP) based transmit power minimization problem dependent on the minimum signal-to-interference-plus-noise ratio (SINR) and energy harvesting (EH) thresholds. We solve the corresponding non-negative convex quadratic optimization problem per time frame of transmitted symbols and study the benefits of proposed design under Zero-Forcing (ZF) Precoding, Direct Demand SLP (DD-SLP), and Squared-Root Demand SLP (RD-SLP) techniques. A static PS-ratio is fixed according to the SINR and EH demands to enable the segregation of intended received signals for information decoding (ID) and EH, respectively. Numerical results show the property conservation of SINR-enhancement via SLP at the ID unit while increasing the harvested energy at each of the end-users. [less ▲]

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See detailAlgorithmic Decision Theory: Lecture notes and presentation slides
Bisdorff, Raymond UL

Learning material (2020)

The objective of this course is to introduce students to ADT, a new interdisciplinary field at the intersection of decision theory, discrete mathematics, theoretical computer science and artificial ... [more ▼]

The objective of this course is to introduce students to ADT, a new interdisciplinary field at the intersection of decision theory, discrete mathematics, theoretical computer science and artificial intelligence. ADT proposes new ideas, approaches and tools for supporting decision making processes in presence of massive databases, combinatorial structures, partial and/or uncertain information, and distributed, possibly inter-operating, decision makers. Such problems arise in several real-world decision making problems such as humanitarian logistics, epidemiology, risk assessment and management, e-government, electronic commerce, and the implementation of recommender systems [less ▲]

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See detailMindfulness in everyday life: Between- and within-person relationships to motivational conflicts
Senker, Kerstin; Fries, Stefan; Grund, Axel UL

in Current Psychology (2020)

Mindfulness has shown beneficial relationships with well-being and self-regulation. We aim to improve the understanding of the effects of between- and within-person differences in mindfulness when dealing ... [more ▼]

Mindfulness has shown beneficial relationships with well-being and self-regulation. We aim to improve the understanding of the effects of between- and within-person differences in mindfulness when dealing with situations of motivational conflict. For this purpose, we conducted an experience sampling study with 56 university students who replied to a total of N = 1889 short questionnaires, which they received via their smartphones over a period of eight consecutive days. In addition to a state mindfulness questionnaire with the facets presence and non-judgment (focusing attention on the experience of the current action and a momentary non-judgmental stance towards these, respectively), the participants received questions about their current affective well-being and perceived intensity of want or should conflict experiences. Multi-level analyses revealed that want conflicts were predicted by both state mindfulness facets, even after momentary affect was controlled. In addition, to be non-judgmental (as a trait), and having momentary presence (as a state), related to lower intensity of should conflicts. The results suggest that being mindful might be a particularly beneficial way of dealing with daily motivational conflicts, which is an essential and frequent task of self-regulation. [less ▲]

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See detailIntersectionality and Adolescent Mental Well-being: A Cross-Nationally Comparative Analysis of the Interplay Between Immigration Background, Socioeconomic Status and Gender
Kern, Matthias Robert UL; Duinhof, Elisa L.; Walsh, Sophie D. et al

in Journal of Adolescent Health (2020), 66(6), 12-20

Purpose: Intersectionality theory highlights the importance of the interplay of multiple social group memberships in shaping individual mental well-being. This article investigates elements of adolescent ... [more ▼]

Purpose: Intersectionality theory highlights the importance of the interplay of multiple social group memberships in shaping individual mental well-being. This article investigates elements of adolescent mental well-being (life dissatisfaction and psychosomatic complaints) from an intersectional perspective. It tests mental well-being consequences of membership in combinations of multiple social groups and examines to what extent such intersectional effects depend on the national context (immigration and integration policies, national-level income, and gender equality). Methods: Using Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy, we assessed the role of the national context in shaping the interplay between immigration background, socioeconomic status, and gender, using data from 33 countries from the 2017/2018 Health Behaviour in School-aged Children survey. Results: We found no uniform intersectionality effects across all countries. However, when allowing the interplay to vary by national context, results did point toward some intersectional effects. Some aggravated negative effects were found for members of multiple disadvantaged social groups in countries with low levels of income equality and restrictive migration policies, whereas enhanced positive effects were found for members of multiple advantaged groups in these countries. Similarly, mitigated negative effects of membership in multiple disadvantaged groups were shown in countries with higher levels of income equality and more inclusive migration policies, whereas mitigated positive effects were found for multiply advantaged individuals. Although for national-level gender equality results pointed in a similar direction, girls’ scores were counterintuitive. High national-level gender equality disproportionately benefitted groups of disadvantaged boys, whereas advantaged girls were doing worse than expected, and reversed effects were found for countries with low gender equality. Conclusions: To fully understand social inequalities in adolescent mental well-being, the interplay between individual-level and national-level indicators must be explored. [less ▲]

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See detailMeasurement invariance of the Positive Gains Scale in families of children with and without disabilities
Jess, Mikeda; Bailey, Tom; Pit-Ten Cate, Ineke UL et al

in Research in Developmental Disabilities (2020), 103

Background Despite the high frequency of case-control studies in the developmental disability literature, there is a paucity of research establishing the measurement equivalence of instruments used, and ... [more ▼]

Background Despite the high frequency of case-control studies in the developmental disability literature, there is a paucity of research establishing the measurement equivalence of instruments used, and particularly those relating to positive perceptions and experiences in family disability research. Aims The present study sought to establish measurement invariance for the Positive Gains Scale (PGS) across 1219 mothers of children with developmental disabilities, 234 mothers of children with spina bifida/hydrocephalus, and 157 mothers of children without disabilities. Methods and Procedures A three-step test for measurement invariance across the three groups was conducted using Multigroup Confirmatory Factor Analysis. Outcomes and Results Loadings between the three groups were invariant, suggesting the criteria to assume metric invariance was met. However, the assumption of scalar invariance was not met, suggesting that item intercepts differed between the three groups. Conclusions and Implications Our findings suggest that the PGS cannot be meaningfully used to compare outcomes between mothers of children with developmental disabilities and other mothers. These findings may have wider implications for research utilising well-being measures to make comparisons with carers of children with developmental disabilities. [less ▲]

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See detailAttitudes towards Multiculturalism in Luxembourg: Measurement Invariance and Factor Structure of the Multicultural Ideology Scale
Stogianni, Maria UL; Murdock, Elke UL; He, Jia et al

E-print/Working paper (2020)

The present study examined the dimensionality and the measurement invariance of the Multicultural Ideology Scale (MCI; Berry & Kalin, 1995), and mean differences across different cultural groups within ... [more ▼]

The present study examined the dimensionality and the measurement invariance of the Multicultural Ideology Scale (MCI; Berry & Kalin, 1995), and mean differences across different cultural groups within the multilingual, multicultural context of Luxembourg. With 47% of the citizens being non-nationals, minority and majority are increasingly difficult to define and Luxembourg becomes a unique context to study attitudes towards diversity. Our sample included 1488 participants from diverse ethnic backgrounds who completed the survey in German, French or English. In contrast to previous findings, our analyses revealed a two-dimensional structure, distinguishing between positive and negative attitudes towards multiculturalism. The factor structure was partially invariant across ethnocultural groups: Configural and metric invariance were established across natives and non-natives, scalar invariance only across gender groups. Natives and male participants reported more negative attitudes towards multiculturalism. We discuss the importance of assessing measurement invariance and provide recommendations to improve the assessment of psychological multiculturalism. [less ▲]

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See detailGuidelines for Operationalizing Policy Coherence for Development (PCD) as a Methodology for the Design and Implementation of Sustainable Development Strategies
Koff, Harlan UL; Challenger, Antony; Portillo, Israel

in Sustainability (2020), 12(4055), 1-23

Policy Coherence for Development (PCD) is considered a pillar of the 2030 Sustainable Development Agenda. It aims to promote whole of government approaches to sustainable development. Despite its ... [more ▼]

Policy Coherence for Development (PCD) is considered a pillar of the 2030 Sustainable Development Agenda. It aims to promote whole of government approaches to sustainable development. Despite its prominence in development cooperation discussions, many national development professionals or stakeholders have not heard of PCD, indicating that its effectiveness is significantly limited. This article contends that the impact of PCD has not been maximized because it has been presented as a political objective or a policy tool by multilateral organizations and their member states. Instead, the article argues that PCD should be implemented as a methodology that can be adopted by domestic government and non-governmental actors alike, in order to understand trade-offs and co-benefits within and between policy sectors, thus promoting a participative approach. I-GAMMA is a research project in Mexico that examines data-driven public policy in order to promote PCD. It is based on in-depth reviews of policy documents and interviews with development actors. It is committed to open data, evidence-based policymaking, and collaborative dialogue between academics, government officials, and representatives of civil society organizations in sustainable development discussions. In the results section of this article, the project proposes participative PCD as a methodology for policy analysis through which a plurality of actors can identify mechanisms that either reinforce or undermine sustainable development strategies. This section then applies the methodology to the governance of protected natural areas in Mexico. The discussion section and the conclusions highlight the relevance of this approach for participative policymaking in sustainable development. [less ▲]

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See detailStudent translanguaging: insights into resource combinations and reflections of classroom practices
Degano, Sarah UL

Presentation (2020, May 15)

This presentation adopts a multimodal perspective on translanguaging. It focusses on the extent to which multilingual pupils’ translanguaging practices provide insights into the semiotic repertoires of ... [more ▼]

This presentation adopts a multimodal perspective on translanguaging. It focusses on the extent to which multilingual pupils’ translanguaging practices provide insights into the semiotic repertoires of the students and connect to the classroom practices of their learning environment as well as to those of the larger community. [less ▲]

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See detailMISCAST: MIssense variant to protein StruCture Analysis web SuiTe
Iqbal, Sumaiya; Hoksza, David UL; Pérez-Palma, Eduardo et al

in Nucleic Acids Research (2020)

Human genome sequencing efforts have greatly expanded, and a plethora of missense variants identified both in patients and in the general population is now publicly accessible. Interpretation of the ... [more ▼]

Human genome sequencing efforts have greatly expanded, and a plethora of missense variants identified both in patients and in the general population is now publicly accessible. Interpretation of the molecular-level effect of missense variants, however, remains challenging and requires a particular investigation of amino acid substitutions in the context of protein structure and function. Answers to questions like ‘Is a variant perturbing a site involved in key macromolecular interactions and/or cellular signaling?’, or ‘Is a variant changing an amino acid located at the protein core or part of a cluster of known pathogenic mutations in 3D?’ are crucial. Motivated by these needs, we developed MISCAST (missense variant to protein structure analysis web suite; http://miscast.broadinstitute.org/). MISCAST is an interactive and user-friendly web server to visualize and analyze missense variants in protein sequence and structure space. Additionally, a comprehensive set of protein structural and functional features have been aggregated in MISCAST from multiple databases, and displayed on structures alongside the variants to provide users with the biological context of the variant location in an integrated platform. We further made the annotated data and protein structures readily downloadable from MISCAST to foster advanced offline analysis of missense variants by a wide biological community. [less ▲]

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See detailFlucht- und Wanderungsbewegungen in Ostbelgien 1944/45
Brüll, Christoph UL

Scientific Conference (2020, May 13)

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