Paris West University Nanterre La Défense

About: Paris West University Nanterre La Défense is a education organization based out in Paris, France. It is known for research contribution in the topics: Computer science & Politics. The organization has 895 authors who have published 1430 publications receiving 21712 citations.

All-dielectric transformation medium mimicking a broadband converging lens

Abstract: Radio waves carrying orbital angular momentum (OAM) may potentially increase spectrum efficiency and channel capacity based on their extra rotational degree of freedom. However, due to their divergence characteristics, vortex waves are not suitable to transmit over a long distance in the radio frequency (RF) and microwave domains. In this paper, a transformation optics (TO) based all-dielectric converging lens is proposed. The beam divergence angle of the vortex wave passing through the lens can be decreased from 25° to 9°. The transformed material parameters of the converging lens are determined by solving Laplace's equation subject to specific boundary conditions. Far-field antenna radiation patterns as well as near-field helical phase and electric field amplitude distributions obtained from numerical simulations are reported, demonstrating the broadband characteristics of the proposed microwave lens. Moreover, the all-dielectric compact lens design comprised by a graded permittivity profile can be fabricated by additive manufacturing technology, which greatly facilitates the potential development and application of vortex wave based wireless communications.

Trial and settlement negotiations between asymmetrically skilled parties

Abstract: Parties engaged in a litigation generally enter the discovery process with different informations regarding their case and/or an unequal endowment in terms of skill and ability to produce evidence and predict the outcome of a trial. Hence, they have to bear different legal costs to assess the (equilibrium) plaintiff’s win rate. The paper analyses pretrial negotiations and revisits the selection hypothesis in the case where these legal expenditures are private information. This assumption is consistent with empirical evidence (Osborne, 1999). Two alternative situations are investigated, depending on whether there exists a unilateral or a bilateral informational asymmetry. Our general result is that efficient pretrial negotiations select cases with the smallest legal expenditures as those going to trial, while cases with largest costs prefer to settle. Under the one-sided asymmetric information assumption, we find that the American rule yields more trials and higher aggregate legal expenditures than the French and British rules. The two-sided case leads to a higher rate of trials, but in contrast provides less clear-cut predictions regarding the influence of fee-shifting.

Is the European Sovereign Crisis Self-Fulfilling?- Empirical Evidence About the Drivers of Market Sentiments

Abstract: We assess the nature of the European sovereign crisis in the light of a model borrowed from the second generation of currency crises. We bring the theory to the data to empirically test the presence of self-fulfilling dynamics and to identify what may have driven the market sentiment during this crisis. To do so we estimate the probability of default of five European 'peripheral' countries during January 2006 to September 2011 with a panel smooth threshold regression. Our estimation results suggest that 1/ both the fundamentals and 'animal spirit' ignited the European sovereign crisis; 2/ the sovereign Credit Default Swap market (CDS), the rating agencies and the CDS of the banking sector have played dominant roles in driving market sentiments.

Psychosocial Effects and Use of Communication Technologies during Home Confinement in the First Wave of the COVID-19 Pandemic in Italy and The Netherlands

Abstract: (1) Background: The COVID-19 pandemic forced people from all around the globe to strongly modify their daily routines, putting a significant strain on the social aspects of daily lives. While the first wave of the pandemic was a very challenging time in all countries, it is still uncertain whether various lockdown intensities and infection rates differed regarding their psychosocial impact. This work therefore aimed to investigate (i) the psychosocial effects of home confinement in two European countries that underwent different lockdown intensities: Italy and the Netherlands and (ii) the role of communication technology in relation to feelings of loneliness. (2) Methods: A cross-sectional online survey inquiring about different psychosocial variables and the use of and satisfaction towards communication technology was circulated among the general public during the first wave of the COVID-19 pandemic. In total, 629 participants (66% female, 68% from the Netherlands) answered each question twice, referring to "before" and "during" the pandemic. (3) Results: We found significant negative effects of COVID-19 home confinement on depressive feelings (p < 0.001, %∆ = +54%), loneliness (p < 0.001, %∆ = +37.3%), life satisfaction (p < 0.001, %∆ = -19.8%) and mental wellbeing (p < 0.001, %∆ = -10.6%) which were accompanied with a significantly increased need for psychosocial support (p < 0.001, %∆ = +17.3%). However, the magnitude of psychosocial impact did not significantly differ between residents undergoing a more intense (Italy) versus a less intense (Netherlands) lockdown, although the decrease in social participation was found to be significantly different for both countries (z = -7.714, p < 0.001). Furthermore, our findings demonstrate that the increase in loneliness was associated with the adoption of new digital communication tools (r = 0.21, p < 0.001), and significantly higher for individuals who started to adopt at least one new digital communication tool during confinement than for those who did not (z = -4.252, p < 0.001). (4) Conclusions: This study highlights that, although COVID-19 home confinement significantly impacted psychosocial wellbeing during the first wave of the pandemic, this impact did not differ based on lockdown intensity. Recognizing the increasing adoption of digital communication technology in an attempt to reduce lockdown loneliness, future studies should investigate what is needed from the technology to achieve this effect.