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Full-Text Articles in Physical Sciences and Mathematics
On The Difficulty Of Manhattan Channel Routing, Ronald I. Greenberg, Joseph Jaja, Sridhar Krishnamurthy
On The Difficulty Of Manhattan Channel Routing, Ronald I. Greenberg, Joseph Jaja, Sridhar Krishnamurthy
Computer Science: Faculty Publications and Other Works
We show that channel routing in the Manhattan model remains difficult even when all nets are single-sided. Given a set of n single-sided nets, we consider the problem of determining the minimum number of tracks required to obtain a dogleg-free routing. In addition to showing that the decision version of the problem isNP-complete, we show that there are problems requiring at least d+Omega(sqrt(n)) tracks, where d is the density. This existential lower bound does not follow from any of the known lower bounds in the literature.
Packet Routing In Networks With Long Wires, Ronald I. Greenberg, H.-C. Oh
Packet Routing In Networks With Long Wires, Ronald I. Greenberg, H.-C. Oh
Computer Science: Faculty Publications and Other Works
In this paper, we examine the packet routing problem for networks with wires of differing length. We consider this problem in a network independent context, in which routing time is expressed in terms of “congestion” and “dilation” measures for a set of packet paths. We give, for any constant ε > 0, a randomized on-line algorithm for routing any set of N packets in O((Clg^ε(Nd)+Dlg(Nd))/lglg(Nd)) time, where C is the maximum congestion and D is the length of the longest path, both taking wire delays into account, and d is the longest path in terms of number of wires. We also …
Finding A Maximum-Density Planar Subset Of A Set Of Nets In A Channel, Ronald I. Greenberg, Jau-Der Shih
Finding A Maximum-Density Planar Subset Of A Set Of Nets In A Channel, Ronald I. Greenberg, Jau-Der Shih
Computer Science: Faculty Publications and Other Works
We present efficient algorithms to find a maximum-density planar subset of n 2-pin nets in a channel. The simplest approach is to make repeated usage of Supowit's dynamic programming algorithm for finding a maximum-size planar subset, which leads to O(n^3) time to find a maximum-density planar subset. But we also provide an algorithm whose running time is dependent on other problem parameters and is often more efficient. A simple bound on the running time of this algorithm is O(nlgn+n(t+1)w), where t is the number of two-sided nets, and w is the number of nets in the output. Though the worst-case …