Integration of navigation and action selection functionalities in a computational model of cortico-basal ganglia-thalamo-cortical loops

This article describes a biomimetic control architecture affording an animat both action selection and navigation functionalities. It satisfies the survival constraint of an artificial metabolism and supports several complementary navigation strategies. It builds upon an action selection model based on the basal ganglia of the vertebrate brain, using two interconnected cortico-basal ganglia-thalamo-cortical loops: a ventral one concerned with appetitive actions and a dorsal one dedicated to consummatory actions. The performances of the resulting model are evaluated in simulation. The experiments assess the prolonged survival permitted by the use of high level navigation strategies and the complementarity of navigation strategies in dynamic environments. The correctness of the behavioral choices in situations of antagonistic or synergetic internal states are also tested. Finally, the modelling choices are discussed with regard to their biomimetic plausibility, while the experimental results are estimated in terms of animat adaptivity

A Pipeline Story: The Evolving Autonomy of Canadian Municipalities

Pipeline projects in Canada often polarize citizens and governments from coast to coast. While the approval of such projects may seem simple from a constitutional standpoint, recent events show that legal realities and complexities truly add some grit in the works of pipeline projects even if the federal government is constitutionally responsible for the ultimate approval or refusal of projects because of their interprovincial nature. In fact, the passage of a pipeline involves a number of other considerations and fields of law, such as the environment, land use planning, risk management, and human rights, which are within the jurisdiction of federal or provincial legislatures, or both, and also increasingly the business of municipalities. While municipal powers continue, twenty-five years after important statutory reforms were launched, to be considerably limited by the provinces, courts have made it clear that municipal by-laws apply to federal pipelines, unless they have an excessive or serious detrimental effect on the construction or exploitation of such an undertaking, or if they contradict the operation or the purpose of federal legislation. It is in this multi-layered context that this article discusses the legal autonomy of Canadian municipalities in regard to the pipeline debate in Canada, exploring the content, the extent, and the limits of their powers

Spectral-phase interferometry for direct electric-field reconstruction applied to seeded extreme-ultraviolet free-electron lasers

We present a setup for complete characterization of femtosecond pulses generated by seeded free-electron lasers (FEL's) in the extreme-ultraviolet spectral region. Two delayed and spectrally shifted replicas are produced and used for spectral phase interferometry for direct electric field reconstruction (SPIDER). We show that it can be achieved by a simple arrangement of the seed laser. Temporal shape and phase obtained in FEL simulations are well retrieved by the SPIDER reconstruction, allowing to foresee the implementation of this diagnostic on existing and future sources. This will be a significant step towards an experimental investigation and control of FEL spectral phase

Multipath optimized link state routing for mobile ad hoc networks

International audienceMultipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications. Our protocol, called MP-OLSR (MultiPath OLSR), is a multipath routing protocol based on OLSR. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints