A case study on regularity in cellular network deployment

This paper aims to validate the $\beta$-Ginibre point process as a model for the distribution of base station locations in a cellular network. The $\beta$-Ginibre is a repulsive point process in which repulsion is controlled by the $\beta$ parameter. When $\beta$ tends to zero, the point process converges in law towards a Poisson point process. If $\beta$ equals to one it becomes a Ginibre point process. Simulations on real data collected in Paris (France) show that base station locations can be fitted with a $\beta$-Ginibre point process. Moreover we prove that their superposition tends to a Poisson point process as it can be seen from real data. Qualitative interpretations on deployment strategies are derived from the model fitting of the raw data

On a few statistical applications of determinantal point processes

International audienceDeterminantal point processes (DPPs) are a repulsive distribution over configurations of points. The 2016 conference Journées "Modélisation Aléatoire et Statistique" (MAS) of the French society for applied and industrial mathematics (SMAI) featured a session on statistical applications of DPPs. This paper gathers contributions by the speakers and the organizer of the session.Les processus ponctuels déterminantaux (DPP) sont des distributions répulsives sur des configurations de points. Au cours des journées "Modélisation Aléatoire et Statistique" (MAS) 2016 de la Société française de Mathématiques Appliquées et Industrielles (SMAI), nous avons organisé une session sur les applications statistiques des DPP. Cet article rassemble des contributions des orateurs et de l'organisateur

Kilometer range filamentation

International audienceWe demonstrate for the first time the possibility to generate long plasma channels up to a distance of 1 km, using the terawatt femtosecond T&T laser facility. The plasma density was optimized by adjusting the chirp, the focusing and beam diameter. The interaction of filaments with transparent and opaque targets was studied

Farm-scale Water Management in Adaptation to Climate Change in Morocco

Morocco is already experiencing high levels of water scarcity, and rainfall is predicted to decrease by 20% to 50% under different climate change scenarios. As currently Morocco relies on large reservoirs built to achieve basin-scale water resources management, small-scale reservoirs are investigated here as a possible way to adapt to these dryer conditions and to collect overland flow for irrigation purposes before its evaporation or infiltration into the ground. We investigate a potential shift from basin-scale to farm-scale water resource management. A prototype of such small reservoirs has been built in the experimental farm of Benguerir and this thesis studies its catchment as well as the extent to which this technology could scale up in other regions of Morocco. Runoff production in the form of overland flow is simulated according to the Green-Ampt model while considering the formation of a thin crust of clay typical of dry environments such as southern Morocco. Overland flow is used as input to different models of reservoir management in order to determine the optimal capacity of a potential reservoir in a particular location as function of its catchment area, rainfall pattern, soil type, cost of construction, water price, as well as crops water requirements. Within reasonable assumptions, capacities close to the reservoir in Benguerir (4000 m³) are estimated. However, the results are sensitive to multiple partially unknown parameters such as soil heterogeneity, the intra-day distribution of rainfall and the ratio between construction cost and water price.M.Eng

Stein's method and Papangelou intensity for Poisson or Cox process approximation

In this paper, we apply the Stein's method in the context of point processes, namely when the target measure is the distribution of a finite Pois-son point process. We show that the so-called Kantorovich-Rubinstein distance between such a measure and another finite point process is bounded by the $L^1$-distance between their respective Papangelou intensities. Then, we deduce some convergence rates for sequences of point processes approaching a Poisson or a Cox point process

On a few statistical applications of determinantal point processes

International audienceDeterminantal point processes (DPPs) are a repulsive distribution over configurations of points. The 2016 conference Journées "Modélisation Aléatoire et Statistique" (MAS) of the French society for applied and industrial mathematics (SMAI) featured a session on statistical applications of DPPs. This paper gathers contributions by the speakers and the organizer of the session.Les processus ponctuels déterminantaux (DPP) sont des distributions répulsives sur des configurations de points. Au cours des journées "Modélisation Aléatoire et Statistique" (MAS) 2016 de la Société française de Mathématiques Appliquées et Industrielles (SMAI), nous avons organisé une session sur les applications statistiques des DPP. Cet article rassemble des contributions des orateurs et de l'organisateur

On a few statistical applications of determinantal point processes

Determinantal point processes (DPPs) are a repulsive distribution over configurations of points. The 2016 conference Journées Modélisation Aléatoire et Statistique (MAS) of the French society for applied and industrial mathematics (SMAI) featured a session on statistical applications of DPPs. This paper gathers contributions by the speakers and the organizer of the session

Study of Filamentation Threshold in Zinc Selenide

The possibility of creating filaments with laser wavelengths ranging from 800 nm to 2.4 mu m was investigated using an OPA laser system. Zinc Selenide\u27s (ZnSe) unique characteristics - small band gap E-gZnSe = 2.67eV and positive dispersion for this wavelength range - are well suited for filamentation study where multi-photon absorption can be achieved with two to six photons

Plant–herbivore interactions: Experimental demonstration of genetic variability in plant–plant signalling

International audiencePlant-herbivore interactions mediated by plant-plant signalling have been documented in different species but its within-species variability has hardly been quantified. Here, we tested if herbivore foraging activity on plants was influenced by a prior contact with a damaged plant and if the effect of such plant-plant signalling was variable across 113 natural genotypes of Arabidopsis thaliana. We filmed the activity of the generalist herbivore Cornu aspersum during 1 h on two plants differing only in a prior contact with a damaged plant or not. We recorded each snails' first choice, and measured its first duration on a plant, the proportion of time spent on both plants and leaf consumption. Overall, plant-plant signalling modified the foraging activity of herbivores in A. thaliana. On average, snails spent more time and consumed more of plants that experienced a prior contact with a damaged plant. However, the effects of plant-plant signalling on snail behaviour was variable: depending on genotype identity, plant-plant signalling made undamaged plants more repellant or attractive to snails. Genome-wide associations revealed that genes related to stress coping ability and jasmonate pathway were associated to this variation. Together, our findings highlight the adaptive significance of plant-plant signalling for plant-herbivore interactions