1,674 research outputs found
Singular quasilinear elliptic systems in
The existence of positive weak solutions to a singular quasilinear elliptic
system in the whole space is established via suitable a priori estimates and
Schauder's fixed point theorem
On a Dirichlet problem with -Laplacian and parametric concave-convex nonlinearity
A homogeneous Dirichlet problem with -Laplace differential operator
and reaction given by a parametric -convex term plus a -concave one is
investigated. A bifurcation-type result, describing changes in the set of
positive solutions as the parameter varies, is proven. Since for
every admissible the problem has a smallest positive solution , both monotonicity and continuity of the map are studied.Comment: 12 pages, comments are welcom
How does a bicycle work? A new instrument to assess mechanical reasoning in school aged children
This study demonstrated that a brief interview can reveal the mechanical reasoning that could not be assessed via the Bicycle Drawing Test. This study, conducted on 190 children (6 to 11 years old), shows that mechanical reasoning improves with age. It shows correlations with spatial reasoning and motor control, and with visual reasonin
Swarm robotics in wireless distributed protocol design for coordinating robots involved in cooperative tasks
The mine detection in an unexplored area is an optimization problem where multiple mines, randomly distributed throughout an area, need to be discovered and disarmed in a minimum amount of time. We propose a strategy to explore an unknown area, using a stigmergy approach based on ants behavior, and a novel swarm based protocol to recruit and coordinate robots for disarming the mines cooperatively. Simulation tests are presented to show the effectiveness of our proposed Ant-based Task Robot Coordination (ATRC) with only the exploration task and with both exploration and recruiting strategies. Multiple minimization objectives have been considered: the robots' recruiting time and the overall area exploration time. We discuss, through simulation, different cases under different network and field conditions, performed by the robots. The results have shown that the proposed decentralized approaches enable the swarm of robots to perform cooperative tasks intelligently without any central control
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