Online multiple-strip packing

Online strip packing with modifiable boxes

Online Strip Packing with Polynomial Migration

We consider the relaxed online strip packing problem, where rectangular items arrive online and have to be packed into a strip of fixed width such that the packing height is minimized. Thereby, repacking of previously packed items is allowed. The amount of repacking is measured by the migration factor, defined as the total size of repacked items divided by the size of the arriving item. First, ...

Approximation Algorithms for Multiple Strip Packing

In this paper we study the Multiple Strip Packing (MSP) problem, a generalization of the well-known Strip Packing problem. For a given set of rectangles, r1, . . . , rn, with heights and widths ≤ 1, the goal is to find a non-overlapping orthogonal packing without rotations into k ∈ N strips [0, 1]× [0,∞), minimizing the maximum of the heights. We present an approximation algorithm with absolute...

Strip Packing vs. Bin Packing

In this paper we establish a general algorithmic framework between bin packing and strip packing, with which we achieve the same asymptotic bounds by applying bin packing algorithms to strip packing. More precisely we obtain the following results: (1) Any offline bin packing algorithm can be applied to strip packing maintaining the same asymptotic worst-case ratio. Thus using FFD (MFFD) as a su...

A note on the lower bound for online strip packing

This note presents a lower bound of 3/2+ √ 33/6 ≈ 2.457 on the competitive ratio for online strip packing. The instance construction we use to obtain the lower bound was first coined by Brown, Baker and Katseff [2]. Recently this instance construction is used to improve the lower bound in computer aided proofs. We derive the best possible lower bound that can be obtained with this instance cons...