In this paper, we present a novel method for performing collective transport in the presence of obstacles. Three robots are physically connected to an object to be transported from a start to a goal location. The task is particularly challenging because the robots have a heterogeneous perception of the environment. In fact, the goal and the obstacles can be perceived only by some of the robots....

OBJECTIVE Patients with rheumatoid arthritis (RA) are at increased risk of falling. In healthy elderly persons with a history of falling, a reduced ability to avoid obstacles while walking has been shown to relate to increased fall risk. The aim of this study was to determine whether this potential risk factor for falls would also be present in persons with RA. METHODS Twelve RA patients and ...

We prove existence, uniqueness and optimal regularity of solutions to the stationary obstacle problem defined by the fractional Laplacian operator with drift, in the subcritical regime. As in [1], we localize our problem by considering a suitable extension operator introduced in [2]. The structure of the extension equation is different from the one constructed in [1], in that the obstacle funct...

In an excitable medium, wave breaks are essential for spiral wave formation. Although wave breaks can result from collisions between a wave and an obstacle, it is only when the resultant wave fragments separate from the obstacle ~wave-front–obstacle separation! that a spiral wave will begin to develop. We explored collisions between a piecewise linear obstacle and an incident wave front while v...

Spatio-temporal gaze behaviour patterns were analysed as normal participants wearing a mobile eye tracker approached and stepped over obstacles of varying height in the travel path. We examined the frequency and duration of three types of gaze fixation with respect to the participants' stepping patterns: obstacle fixation (ObsFix); travel fixation (TravFix) (when the gaze is stable and travelli...

We developed a novel locomotor task in which cats step over obstacles that move at a different speed from that of the treadmill on which the cat is walking: we refer to this as a visual dissociation locomotion task. Slowing the speed of the obstacle with respect to that of the treadmill sometimes led to a major change in strategy so that cats made two steps with the hindlimbs before stepping ov...

In this paper, the bisection of the local mesh refinement in self adaptive finite element is applied to the obstacle problem of elliptic variational inequalities .We try to find the approximated region of the contact in the obstacle problem efficiently .Numerical examples are given for the obstacle problem. Key-Words: obstacle problem, variational inequalities, self adaptive finite element, bis...

This paper proposes a novel vector field navigation method by using the velocity vector of a robot to avoid obstacles in dynamic environment. Shifting vector and virtual obstacle are proposed to derive the center of repulsive field which makes the robot move away from the obstacle: The shifting vector is derived from the velocity vector of the robot and the obstacle and the virtual obstacle is ...

The obstacle problem is a linearized version of the problem of stretching an elastic membrane over an obstacle. One of its central features is that the solution will divide the original domain into a set of points where the membrane lies strictly above the obstacle and satisfies a partial differential equation, and its complement, where the membrane touches the obstacle. The fact that these set...