New perspectives in VLSI design automation: deterministic packing by Sequence Pair

Abstract

In the paper we consider a problem of packing rectangular blocks on a plane, which is known as Block Packing Problem (BPP). This problem is a central issue of the modern VLSI chips design methods. Basing on a new interpretation of the Sequence-Pair representation of the packing solution-space, which is based on Complementary Mirror Constraint Graphs (CMCG), we develop the efficient method of neighborhood exploration. This method might be able to improve the efficiency of other neighborhood-based search methods, such as simulated annealing or tabu search, as well as, to construct efficient heuristics. We illustrate application of the developed method by constructing a heuristic algorithm for solving BPP and comparing its efficiency and effectiveness to the algorithms commonly used so far.

Handling precedence constraints in scheduling problems by the sequence pair representation

“…The second variant evaluates a SP as feasible, if its imposed horizontal constraint graph avoids a given edge set E. We call such SP a a-feasible. We present the algorithm in the form of Janiak et al (2010) to ease integration in the case of explicit-feasible solution space. Presented results can also be combined with neighborhood evaluation techniques described in Imahori et al (2005).…”

“…To not test the proposed approach on just random solutions, the experiment was designed to utilize most common approaches to problem solving-we developed constructive heuristic based on NEH (Nawaz et al 1983) as a generator of starting solutions and metaheuristics based on the Simulated Annealing (SA) framework. Both considered techniques has been successively applied in the vast number of areas, e.g., Janiak et al (2010); Blum and Roli (2003); Blum et al (2008).…”