Neolithic genomic data from southern France showcase intensified interactions with hunter-gatherer communities

SummaryArchaeological research shows that the dispersal of the Neolithic took a more complex turn when reaching western Europe, painting a contrasted picture of interactions between autochthonous hunter-gatherers (HGs) and incoming farmers. In order to clarify the mode, the intensity, and the regional variability of biological exchanges implied in these processes, we report new palaeogenomic data from Occitanie, a key region in Southern France. Genomic data from 28 individuals originating from six sites spanning from c. 5,500 to c. 2,500 BCE allow us to characterize regional patterns of ancestries throughout the Neolithic period. Results highlight major differences between the Mediterranean and Continental Neolithic expansion routes regarding both migration and interaction processes. High proportions of HG ancestry in both Early and Late Neolithic groups in Southern France support multiple pulses of inter-group gene flow throughout time and space and confirm the need for regional studies to address the complexity of the processes involved

Robust D Stabilization Of A Polytope Of Matrices

The problem of stabilization of a polytope of matrices in a subregion DR of the complex plane is revisited. A new sufficient condition of robust DR stabilization is given. It implies the solution of an LMI involving matrix variables constrained by a nonlinear algebraic relation. Some LMI relaxations are first proposed. Then, it is shown that a cone complementarityformulation of this condition allows to associate an efficientiterativenumerical procedure which leads to a low computational burden. This algorithm is tested on differentnumerical examples for which existing approaches in control literature fail

Robust State Feedback D Stabilization via a Cone Complementary Algorithm

The problem of stabilization of a polytope of matrices in a subregion of the complex plane is revisited. A new sufficient stabilization is given. It implies the solution of an involving matrix variables constrained by a nonlinear algebraic relation. A cone complementarity formulation of this condition allows to associate an efficient iterative numerical procedure which leads to a low computational burden. This algorithm is tested on different numerical examples for which existing approaches in control literature fail

Discussion on: Design of low order robust controllers for a VSC HVDC power plant terminal

status: publishe

Minimum-Fuel Fixed-Time Impulsive Elliptic Glideslope Guidance Algorithms Using Semidefinite Programming

International audienceA new minimum-fuel glideslope guidance algorithm for approaching autonomously a target evolving on an elliptic orbit is proposed in this paper. Assuming chemical propulsion, the present work aims at enhancing Hablani's seminal method. Although this reference method is efficient and easy to implement, there is no direct control on the fuel consumption and the guidance error. By identifying some relevant degrees of freedom, a new formulation of the glideslope guidance algorithm is proposed to address these issues. For a fixed-time rendezvous and a given number of maneuvers, the fuel-optimal multipulse glideslope is expressed as a semidefinite programming problem. A solution to this optimization problem provides an impulsive control sequence that guarantees a minimal consumption and makes sure the chaser's trajectory remains included inside a user-defined corridor. Besides, if trajectory constraints are removed, or if a specific direction is considered (V-bar or R-bar), then the formulation is reduced to a simple linear programming problem. Three realistic scenarios of rendezvous are simulated to illustrate the benefit of the proposed methodology