vibration cutting (vc), elliptical vibration cutting (evc) and ordinary cutting (oc) of in738 work-pieces have been experimentally investigated in the present research. the experiments were carried out by using single crystal diamond tool and ultra-precision cnc lathe. vibration frequency is 36.16khz and the amplitude is . the influence of various cutting parameters including cutting speed, fee...

In this paper, we consider the three-dimensional orthogonal bin packing problem, which is a generalization of the well-known bin packing problem. We present new lower bounds for the problem and demonstrate that they improve the best previous results. The asymptotic worst-case performance ratio of the lower bounds is also proved. In addition, we study the non-oriented model, which allows items t...

In the Bin Packing Problem with Conflicts (BPPC), we are given a set V = {1, 2, . . . , n} of items, each item i having a non-negative weight wi, and an infinite number of identical bins of weight capacity W . We are also given a conflict graph G = (V,E), where E is a set of edges such that (i, j) ∈ E when i and j are in conflict. Items in conflict cannot be assigned to the same bin. The aim of...

This paper provides a review aimed at comparing cutting and packing (C&P) research in the textile industry area of zero-waste fashion design (ZWFD). Both domains seek to minimise waste material while approaching problem from very different perspectives. The C&P investigates use mathematical computational techniques for minimising marker planning problem, ZWFD creative pattern making solutions s...

Nesting problems are combinatorial optimisation problems where one or more pieces of material or space must be divided into smaller irregular pieces, minimising the waste. In OR, the state-of-the-art in nesting problems is to solve them by means of heuristic algorithms; the use of mixed integer programming models can handle only rather small instances. The satisfaction of geometric constraints ...

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...

the crystal structure of the title schiff base complex is obtained by single-crystal x-ray diffraction data.the solid state structure determination reveals that the coordination geometry around the copper(ii) center istetrahedrally distorted square-planar. the crystal packing shows one dimensional infinite chains which arisesfrom the intermolecular interaction and stabilize the crystal packing.

The bin packing problem is a well-studied problem in combinatorial optimization. In the classical bin packing problem, we are given a list of real numbers in (0, 1] and the goal is to place them in a minimum number of bins so that no bin holds numbers summing to more than 1. The problem is extremely important in practice and finds numerous applications in scheduling, routing and resource alloca...

abstract: nowadays, the non-traditional processes such as “laser, edm and awj” used for cutting high thickness sheet metal. hardox is hard and tough steel alloy and it has many industrialize applications. one best process to cut the hardox is abrasive water jet (awj) cutting.  it can cuts complex shape with high quality and accurate tolerance.  awj cutting offers certain unique benefits such as...