We give the rst approximation algorithm for the node-weighted Steiner tree problem. Its performance guarantee is within a constant factor of the best possible unless ~ P NP. Our algorithm generalizesâ€¦ (More)

The group Steiner tree problem is a generalization of the Steiner tree problem where we are given several subsets (groups) of vertices in a weighted graph, and the goal is to nd a minimum-weightâ€¦ (More)

We give the first approximation algorithm for the generalized network Steiner problem, a problem in network design. An instance consists of a network with link-costs and, for each pair {i, j} ofâ€¦ (More)

We present an approximation algorithm for solving graph problems in which a low-cost set of edges must be selected that has certain vertex-connectivity properties. In the survivable network designâ€¦ (More)

We present new design and analysis techniques for the synthesis of parallel multiplier circuits that have smaller predicted delay than the best current multipliers. In [4], Oklobdzija et al.â€¦ (More)

We provide constant factor approximation algorithms for covering the nodes of a graph using trees (rooted or unrooted), under the objective function of minimizing the weight of the maximum weightâ€¦ (More)

Several combinatorial optimization problems choose elements to minimize the total cost of constructing a feasible solution that satisfies requirements of clients. In the Steiner Tree problem, forâ€¦ (More)

We study the problem of finding small trees. Classical network design problems are considered with the additional constraint that only a specified number k of nodes are required to be connected inâ€¦ (More)

We study a general class of bicriteria network design problems. A generic p roblem in this class is as follows: Given an undirected graph and two minimization objectiv es (under different costâ€¦ (More)