From the Publisher:
This work covers all aspects of physical design. The book is a core reference for graduate students and CAD professionals. For students, concept and algorithms are presented in an intuitive manner. For CAD professionals, the material presents a balance of theory and practice. An extensive bibliography is provided which is useful for finding advanced material on a topic. At the end of each chapter, exercises are provided, which range in complexity from simple to research level.

Algorithms for VLSI Physical Design Automation

Unit disk graphs are intersection graphs of circles of unit radius in the plane. We present simple and provably good heuristics for a number of classical NP-hard optimization problems on unit disk graphs. The problems considered include maximum independent set, minimum vertex cover, minimum coloring and minimum dominating set. We also present an on-line coloring heuristic which achieves a competitive ratio of 6 for unit disk graphs. Our heuristics do not need a geometric representation of unit disk graphs. Geometric representations are used only in establishing the performance guarantees of the heuristics. Several of our approximation algorithms can be extended to intersection graphs of circles of arbitrary radii in the plane, intersection graphs of regular polygons, and to intersection graphs of higher dimensional regular objects.

Simple heuristics for unit disk graphs

We describe a new implementation of the Edmonds’s algorithm for computing a perfect matching of minimum cost, to which we refer as Blossom V. A key feature of our implementation is a combination of two ideas that were shown to be effective for this problem: the “variable dual updates” approach of Cook and Rohe (INFORMS J Comput 11(2):138–148, 1999) and the use of priority queues. We achieve this by maintaining an auxiliary graph whose nodes correspond to alternating trees in the Edmonds’s algorithm. While our use of priority queues does not improve the worst-case complexity, it appears to lead to an efficient technique. In the majority of our tests Blossom V outperformed previous implementations of Cook and Rohe (INFORMS J Comput 11(2):138–148, 1999) and Mehlhorn and Schafer (J Algorithmics Exp (JEA) 7:4, 2002), sometimes by an order of magnitude. We also show that for large VLSI instances it is beneficial to update duals by solving a linear program, contrary to a conjecture by Cook and Rohe.

Blossom V: a new implementation of a minimum cost perfect matching algorithm

In this paper we give an overview of recent developments in the field of modeling deterministic single-level dynamic lot sizing problems. The focus of this paper is on the modeling of various industrial extensions and not on the solution approaches. The timeliness of such a review stems from the growing industry need to solve more realistic and comprehensive production planning problems. First, several different basic lot sizing problems are defined. Many extensions of these problems have been proposed and the research basically expands in two opposite directions. The first line of research focuses on modeling the operational aspects in more detail. The discussion is organized around five aspects: the set ups, the characteristics of the production process, the inventory, demand side and rolling horizon. The second direction is towards more tactical and strategic models in which the lot sizing problem is a core substructure, such as integrated production-distribution planning or supplier selection. Recent advances in both directions are discussed. Finally, we give some concluding remarks and point out interesting areas for future research.

/pdf/modeling-industrial-lot-sizing-problems-a-review-vruq0a6m3b.pdf

Modeling Industrial Lot Sizing Problems: A Review

NC-Approximation Schemes for NP- and PSPACE-Hard Problems for Geometric Graphs

A study on two geometric location problems

A Study on Two Geometric Location Problems

The real-weight maximum cut of a planar graph is considered. Given an undirected planar graph with real-value weights associated with its edges, the problem is to find a partition of the vertices into two nonempty sets such that the sum of the weights of the edges connecting the two sets is maximum. The conventional maximum cut and minimum cut problems assume nonnegative edge weights, and thus are special cases of the real-weight maximum cut. An O(n/sup 3/2/ log n) algorithm for finding a real-weight maximum cut of a planar graph where n is the number of vertices in the graph is developed. The best maximum cut algorithm previously known for planar graphs has running time of O(n/sup 3/). >

Unifying maximum cut and minimum cut of a planar graph

A DTD-compliant XML document editor is disclosed The XML document editor generates hints for required elements and required element slots automatically in the process of document creation and edition so as to guide the user to produce a valid document, while syntactic violations are avoided at the same time The editor also suggests optional elements that may be added into the document to be edited The user requires no knowledge about XML and DTD to edit DTD-compliant XML documents The editing process is user-interface-neutral, being able to support user interfaces based on tree views, presentation views and forms By combining the DTD-compliant editing process with the simplicity of forms, a simple XML document editor with forms as its user interface is developed

XML document editor

Given the geometry of wires for interconnections, the authors want to assign two conducting layers to the segments of these wires so that the number of vias required is minimized. This layer assignment problem, also referred to as the via minimization problem, has been formulated as finding a maximum cut of a planar graph. The authors propose a novel algorithm for optimal layer assignment under a general model where the planar graph has real-valued edge weights. The time complexity of the proposed algorithm is O(n/sup 3/2/ log n) where n is the number of wire-segment clusters in a given layout. In contrast, all existing optimal algorithms for layer assignment have the time complexity of O(n/sup 3/). >

Y. S. Kuo

Papers

A study on two geometric location problems

A Study on Two Geometric Location Problems

Unifying maximum cut and minimum cut of a planar graph

XML document editor

Fast algorithm for optimal layer assignment