We consider a natural generalization of multiprocessor scheduling, the bin scheduling problem. Here, we model the situation in which working resources are available during separate time windows, or shifts, only. Restricting to scheduling without job preemption, every task must be processed completely during one shift. Our aim is to find a feasible schedule in which the number of required shifts...

This special issue presents 5 articles that cover the methods and applications of meta-heuristics and other related models, which highlight innovation and recent development for challenging problems in industry and science. The issue begins with an article by Bouhmala and Granmo, “Stochastic Learning for SATEncoded Graph Coloring Problems”. The article presents a new algorithm based on the rand...

This paper describes a new placement method based on pattern matching for 2D tiling problems. Tiling problem can be considered as a special case of bin packing. In the proposed method, the representation of the figures and the board is based on directional chain codes. Contrary to other works that the area has been used for the board and the figures, the proposed method is based on usage of the...

Processing Time first algorithm always finds a schedule having makespan within 43 1. Key words, bin packing, multiprocessor scheduling, approximation.Single capacity bin-packing algorithms were applied to solve this problem. Available system resources, the scheduling algorithm must be able to maintain a job working set. Bounds for multiprocessor scheduling with resource.We consider a natural ge...

seed germination, is a new alternative to no-till in areas where poorly drained soils are dominant. Where soil moisture conditions are suitable, strip-tillage creates narrow-width tilled strips, traditionally in the fall, to increase early spring soil evaporation and soil temperature in the top 2 inches. This is particularly effective in poorly drained wet soils, where slightly raised soil stri...

The earliest and the most critical stage in VLSI layout design is the placement. The background of which is the rectangle packing problem: Given set of rectangular modules of arbitrary sizes, place them without overlap on a plane within a rectangle of minimum area. Since the variety of the packing is uncountably infinite, the key issue for successful optimization is the introduction of a finite...

In this paper, application of a multi-objective evolutionary algorithms is explored for solving multi-objective placement, packing, or layout problems. Placement problems are optimization problems concerned with finding an optimal arrangement of multiple items in a large containing region while satisfying prescribed requirements and constraints. This study is applied to the configuration design...

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...

In this paper, the two-dimensional strip packing problem with 3-stage level patterns is tackled using genetic algorithms (GAs). We evaluate the usefulness of a knowledge-based greedy seeding procedure used for creating the initial population. This is motivated by the expectation that the seeding will speed up the GA by starting the search in promising regions of the search space. An analysis of...