We propose query optimization techniques that fully utilize the advantages of path indexes in object-oriented database systems. Although path indexes provide an eecient access to complex objects, little research has been done on query optimization that fully utilize path indexes. We rst devise a generalized index intersection technique, adapted to the structure of the path index extended from c...

Internet routing protocols, such as Open Shortest Path First (OSPF), compute a shortest path tree from each node to other nodes in the network, using link-state information. Such protocols do not consider the queueing situation at a given node. An alternate path of higher cost may be more convenient to use than the optimum path when a long queue is present at the node. This paper proposes a new...

RMIT University Melbourne, BOX 2476V, VIC 3001, Australia, fkist,[email protected] Abstract This paper considers a directed graph G(N;A) with n nodes, m directed arcs and a cost value for each arc. The synthesis of a partially link disjoint pair of paths for a given OD-pair with the minimum total cost is investigated. An algorithm is presented that solves the all-best partially disjoint...

Problem (JSSP) to evaluate the neighborhoods functions that use the non-deterministic algorithms is the calculation of the critical path in a digraph. This paper presents an experimental study of the cost of computation that exists when the calculation of the critical path in the solution for instances in which a JSSP of large size is involved. The results indicate that if the critical path is ...

This paper presents an approximation algorithm for finding a shortest path between two points s and t in a weighted planar subdivision P . Each face f of P is associated with a weight wf , and the cost of travel along a line segment on f is wf multiplied by the Euclidean norm of that line segment. The cost of a path which traverses across several faces of the subdivision is the sum of the costs...

This paper addresses the weighted anisotropic shortest-path problem on a continuous domain, i.e., the computation of a path between two points that minimizes the line integral of a cost-weighting function along the path. The cost-weighting depends both on the instantaneous position and direction of motion. We propose an algorithm for the computation of shortest path that reduces the problem to ...

A computer algorithm for determining optimal surgical paths in the brain is presented. The algorithm computes a cost function associated with each point on the outer brain boundary, which is treated as a candidate entry point. The cost function is determined partly based on a segmentation of the patients images into gray and white matter, and partly based on a spatially transformed atlas of the...

We consider the motion-planning problem of planning a collision-free path of a robot in the presence of risk zones. The robot is allowed to travel in these zones but is penalized in a super-linear fashion for consecutive accumulative time spent there. We suggest a natural cost function that balances path length and risk-exposure time. Specifically, we consider the discrete setting where we are ...

We present a new algorithm, A*Prune, to list (in order of increasing length) the first K Multiple-Constrained-Shortest-Path (KMCSP) between a given pair of nodes in a digraph in which each arc is associated with multiple Quality-of-Service (QoS) metrics. The algorithm constructs paths starting at the source and going towards the destination. But, at each iteration, the algorithm gets rid of all...