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11.
Efficient layout strategies are introduced for automatic nesting using a rule-based heuristic approach to improve the layout
efficiency. Since a large portion of the complexity of the parts layout problem results from the overlapping computation,
geometric redesign techniques are also suggested to reduce the complexity of the problem for a fast and reliable means of
performing overlapping computation. A new heuristic sliding technique is developed to find a near-optimum layout location
from all the feasible arrangements in such a manner that two or more arbitrary parts do not overlap or intersect. An identification
method with a pivoting point is suggested to calculate the boundary of the overlap region in a fast computation time-frame.
Resource plate clipping using virtual memory, based on a polygon clipping algorithm, is also proposed as a technique to reduce
the geometric conditions of the resource plate and the overlap computation time by updating a new stock boundary of the resource
plate for the layout space of the next part after each part is placed. The aim of this article is to develop a rule-based
heuristic nesting system to achieve a new automatic layout on the AutoCAD system. For this implementation, some nesting examples
are demonstrated. A rule-based heuristic approach can be desirable in terms of the layout efficiency and considering the computational
time for nesting problems, and is proposed as a real-time layout simulation method in the industrial field.
Received: October 7, 2002 / Accepted: March 27, 2003
RID="*" 相似文献
12.
Yoshihisa Takekoshi Takafumi Kawamura Hajime Yamaguchi Masatsugu Maeda Norio Ishii Koyu Kimura Tadashi Taketani Akihiko Fujii 《Journal of Marine Science and Technology》2005,10(2):70-81
A new method for designing propeller blade sections is presented. A vortex lattice method is used to evaluate the performance and the time-dependent pressure distribution on the blade surface in a non-uniform flow, while efficient optimization algorithms are used to modify the blade sections. Two different designs were carried out in this study. The first was a design to realize a target pressure distribution in a rotating three-dimensional flow. A two-dimensional wing theory was used to obtain the target pressure distribution. The predicted increase in efficiency and the reduction in the cavity volume were confirmed by model experiments. The second was a design to maximize the propeller efficiency. By this method, the propeller efficiency was improved by 1.2% under the constrains of constant thrust and a prescribed margin for face cavitation. 相似文献
13.
Process planning for a hull structure defines the assembly sequence of the hull block. Although this activity is very important
because the working strategy defines the production costs, to date it has been done manually. To raise the efficiency of this
process, we developed a practical computer-aided process planning system. It has been developed using deliverables obtained
from advanced computer integrated manufacturing system (CIM; ACIM) for shipbuilding projects sponsored by the Ship and Ocean
Foundation (SOF). The system has a knowledge base which contains the know-how of skilled designers as well as design practices,
and allows the assembly sequence of hull parts and intermediate products to be defined automatically. The system has been
integrated with the shipyard CAD system MATES, and put to practical use.
Received: August 19, 2002 / Accepted: November 25, 2002
Address correspondence to: Y. Sasaki (yuuichi_sasaki@mhi.co.jp)
Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:309–315) 相似文献