3-D GPR survey with a modular system: reducing positioning inaccuracies and linear noise

Recently, the use of ground-penetrating radar (GPR) arrays with a large number of antenna elements in a fixed configuration has become more common. The investment needed for these systems is significant. Although gradually expandable modular systems, consisting of antennas which can be used independently, do not match the fast acquisition of detailed datasets by means of multi-channel arrays, they can help finding a compromise between increased acquisition speed and (limited) resources. In modular systems, the separation between transmitter-receiver pairs is often larger than the sampling distance prescribed by the Nyquist theorem. As a consequence, additional profiles have to be recorded in between, which requires a high positioning precision. As a completely identical response for the different antennas in an array is difficult to achieve, stripes can occur in the horizontal slices, especially when ringing occurs. This complicates the interpretation of features in the direction of the survey lines. In this paper, a three-dimensional frequency-wavenumber filter is proposed, consisting in a combination of a circular filter and a fan filter. The application of this filter to GPR data collected at the Roman town Mariana (Corsica, France) showed a reduction of the stripe patterns, allowing a more reliable characterization of subtle archaeological structures

On the Core of an Economy with Multilateral and Multidimensional Environmental Externalities

For simple economic models of transfrontier pollution, Chander and Tulkens (1995) and (1997) have offered a formula for transfers to sustain international cooperation on a voluntary basis and which deter coalitional free-riding under some reasonable behaviours of countries not in the coalition. Their scheme rests on the assumption that pollution is a scalar. Relaxing this assumption, interesting interactions among pollutations arise that call for a new formula. In this paper we extend Chander and Tulkens formula for this more realistic multidimensional context, and thereby enhance the practical and theoretical relevance of their seminal analysis.international pollutions, Nash equilibrium, partial agreement Nash equilibrium, international transfers

Head Coverings in the Courtroom: A Question of Respect for the Judge or of Judicial Tolerance?

The Human Rights Centre at Ghent University (the HRC) first initiated the present research while preparing an amicus curiae brief in the Lachiri v. Belgium case before the European Court of Human Rights (ECtHR). The applicant in Lachiri, who was a civil party in legal proceedings concerning the murder of her brother, was denied access to a Brussels courtroom after refusing to remove her Islamic headscarf . Ms. Lachiri’s admission was refused in reliance on Article 759 of the Belgian Judicial Code (Gerechtelijk Wetboek/ Code Judiciaire), which provides that “[t]he audience will attend the sessions with their heads uncovered, respectfully and silently; whatever the judge commands for the maintenance of order will be punctually and immediately executed.” In its third-party intervention, the HRC sought to supply the ECtHR with additional information concerning three points: the debate on the wearing of Islamic headscarves in Belgium, the history, object and purpose of Article 759 of the Belgian Judicial Code, and the scope of the State margin of appreciation in prohibiting religious items of clothing

On the Core of an Economy with Multilateral and Multidimensional Environmental Externalities

For simple economic models of transfrontier pollution, Chander and Tulkens (1995) and (1997) have offered a formula for transfers to sustain international cooperation on a voluntary basis and which deter coalitionnal free-riding under some reasonable behaviours of countries not in the coalition. Their scheme rests on the assumption that pollution is a scalar. Relaxing this assumption, interesting interactions among pollutants arise that call for a new formula. In this paper we extend Chander and Tulkens formula for this more realistic multidimensional context, and thereby enhance the pratical and theoretical relevance of their seminal analysis.core