In this paper we prove that a particular entry in the scattering matrix, if known for all energies, determines certain rotationally symmetric obstacles in a generalized waveguide. The generalized waveguide X can be of any dimension and we allow either Dirichlet or Neumann boundary conditions on the boundary of the obstacle and on ∂X. In the case of a two-dimensional waveguide, two particular en...

Obstacle identification problems for parabolic equations and systems are considered. Unique continuation property plays an important role in the arguments. These arguments are based on the idea which was first used in the paper MR0847528 (87k:35248) of one of the authors earlier. The technique is applied to inverse problems for slightly compressible fluids and to inverse problems for the heat e...

designing wireless sensor networks should meet appropriate parameters such as quality of service (qos) defined by different users. the variable physical conditions of the environment, processing and transmission power limitations and limited communication capabilities are the most important obstacles that influence qos parameters such as throughput, delay, reliability and network lifetime. the ...

We present eecient algorithms for nding rectilinear collision-free paths between two given points among a set of rectilinear obstacles. Our results improve the time complexity of previous results for nding the shortest rectilinear path, the minimum-bend shortest rectilinear path, the shortest minimum-bend rectilinear path and the minimum-cost rectilinear path. For nding the shortest rectilinear...