This paper addresses a complex real life manufacturing problem that occurs in paper and wood industries: the online bin packing and cutting of small items using parallel machines in a just-in-time environment. The objective is to minimize both the unused areas of the bins and the sum of weighted earliness and tardiness penalties. This NP hard problem is herein solved using an agent-based approa...

The cutting pattern problem of the surplus steel plates (SPCP problem) is difficult to solve. In this paper, a divide-conquer heuristic search approach (DHSA) is proposed for SPCP. Firstly, the related knowledge is extracted and used in transforming the SPCP problem into the special restricted rectangle packing problem (S2RP problem) for each group of surplus(es) and orders. Afterward, feasible...

This paper considers variants of the one-dimensional bin packing (and stock cutting) problem in which both the ordering and orientation of items in a container influences the validity and quality of a solution. Two new real-world problems of this type are introduced, the first that involves the creation of wooden trapezoidal-shaped trusses for use in the roofing industry, the second that requir...

In this paper, the two-dimensional cutting/packing problem with items that correspond to simple polygons that may contain holes are studied in which we propose algorithms based on No-Fit polygon computation. We present a GRASP based heuristic for the 0/1 version of the Knapsack Problem, and another heuristic for the unconstrained version of the Knapsack Problem. This last heuristic is divided i...

Many combinatorial optimization problems such as the bin packing and multiple knapsack problems involve assigning a set of discrete objects to multiple containers. These problems can be used to model task and resource allocation problems in multi-agent systems and distributed systems, and can also be found as subproblems of scheduling problems. We propose bin completion, a branch-and-bound stra...

Main subject of this thesis are approximation algorithms for scheduling and packing, two classical geometrical problems in combinatorial optimization. It is divided into three parts. In the first part we consider a generalization of the strip packing problem or geometrical cutting stock problem. In strip packing a given set of rectangles has to be placed into a strip of fixed width and infinite...

Good algorithms exist for solving the 2D rectangular strip packing problem when the objective is to minimize the amount of wasted material. However, in some applications other criteria are also important. We describe new heuristics for strip packing that optimize not only for wastage, but also for the efficient use of the cutting equipment, by minimizing the number of independent cuts required ...

introduction: controversy remains as to the advantages and disadvantages of pharyngeal packing during septorhinoplasty. our study investigated the effect of pharyngeal packing on postoperative nausea and vomiting and sore throat following this type of surgery or septorhinoplasty.   materials and methods: this clinical trial was performed on 90 american society of anesthesiologists (asa) i or ii...

in this experimental work, by using the method of plasma-chemical etching, we have dealtwith the causes of the creation of a distorted layer on the surface of silicon wafers during mechanicalmachining processes, in addition, the elucidation of connections between the structure of this layer andcharacteristic parameters of the mechanical strength of these wafers have been studied. experimentalre...

crops and agricultural products are subject to natural loading during growth. different mechanical forces are also exerted on them during harvest. one product, sugar cane, experiences large shear forces are during harvest. an examination of the crop properties and machine parameters of sugar cane are necessary to develop appropriate cutting tools and the optimization and design of harvesting ma...