Abstract We prove an existence result for obstacle problems related to convection-diffusion parabolic equations with singular coefficients in the convective term. Our operator is not coercive, function time-dependent irregular, and lower-order term belong a borderline mixed Lebesgue-Marcinkiewicz space.

GOLDMAN, SUSAN R., and VARNHAGEN, CONNIE K. Comprehension of Stories with No-Obstacle and Obstacle Endings. CHILD DEVELOPMENT, 1983, 54, 980-992. Comprehension of stories with and without obstacles to goal attainment was examined. 16 secondand fifth-grade students and 16 adults listened to and read single-episode stories in which (1) the protagonist met the episode goal (no-obstacle ending) and...

Crossing moving obstacles requires different space-time adjustments compared with stationary obstacles. Our aim was to investigate gait spatial and temporal parameters in the approach and crossing phases of a moving obstacle. We hypothesized that obstacle speed affects gait parameters, which allow us to distinguish locomotor strategies. Ten young adults walked and stepped over an obstacle that ...

Reliable detection of non-traversable hazards is a key requirement for off-road autonomous navigation. Under the Army Research Laboratory (ARL) Collaborative Technology Alliances (CTA) program, JPL has evaluated the performance of seven obstacle detection algorithms on a General Dynamics Robotic Systems (GDRS) surveyed obstacle course containing 21 obstacles. Stereo imagery was collected from a...

BACKGROUND AND PURPOSE Obstacle crossing is compromised following stroke. The purpose of this study was to quantify modifications during obstacle clearance following stroke. SUBJECTS Twelve subjects with stroke and 12 subjects without stroke participated in the study. METHODS Kinematic variables were measured while participants crossed a 4-cm-high obstacle. Subjects with stroke walked at a ...

Obstacle avoidance is a key technology of multiagents flocking control. However, most existing research studies assume that the agent can obtain global information about obstacles and have specific constraints on shape boundary obstacles, which easily limit their practical applications. To relax these constraints, we only perceive position obstacle points within its sensing radius propose an po...

PURPOSE Injuries from falls are a serious health issue. Approaches to preventing falls should consider increasing relevant visual information of an obstacle. Obstacle parameters, such as position and height, may be specified by the visible structure of an obstacle. The present study examined the relationship between visible structure of an obstacle and locomotor behaviour. This relationship may...

Obstacle representations of graphs have been investigated quite intensely over the last few years. We focus on graphs that can be represented by a single obstacle. Given a (topologically open) polygon C and a finite set P of points in general position in the complement of C, the visibility graph GC(P ) has a vertex for each point in P and an edge pq for any two points p and q in P that can see ...