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A DIRECTED GRAPH ALGORITHM OF VARIATIONAL GEOMETRY BASED ON GEOMETRIC REASONING
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作者 Ruibin Qu 《Computer Aided Drafting,Design and Manufacturing》 1995年第2期44-52,共4页
The undirected graph to express engineering drawings is discussed .The principle to re-solve and reason the undirected graph is presented, and the algorithm finally transforms theundirected graph into the resolvable d... The undirected graph to express engineering drawings is discussed .The principle to re-solve and reason the undirected graph is presented, and the algorithm finally transforms theundirected graph into the resolvable directed graph. Therefore,a rapid and simple way is suppliedfor variational design. A prototype of this algorithm has been implemented, and some examplesare given. 展开更多
关键词 undirected / directed graph topological / dimensional constraints variational geometry
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SEMANTIC CONSTRAINT MODELER FOR 2D AND 3D GEOMETRY
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作者 JIAO Guofang LIU Shenquan CAD Lab.,Institute of Computing Technology Academia Sinica,Beijing 100080,P.R.China 《Computer Aided Drafting,Design and Manufacturing》 1992年第1期46-57,共12页
Design changes for 2D & 3D geometry are the most important features in the process of product design.Constraint modeling for variationl geometry based on geometric reasoning is one of the best approaches for this ... Design changes for 2D & 3D geometry are the most important features in the process of product design.Constraint modeling for variationl geometry based on geometric reasoning is one of the best approaches for this goal.However,it is difficult for the proposed systems to maintain or handle the consistency and completeness of the constraint model of the design objects.To change this situation,a semantic model and its control approach are presented,aiming at the integration of the data,knowledge and method related to design objects.Aconstraint definition system for in- teractively defining the semantic model and a prototype modeler based on the semantic model are also implemented to examine the idea which is extended to 3D geometric design too. 展开更多
关键词 variational geometry constraint-based modeller semantic model object oriented knowledge representation
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Effects of cluster land reclamation projects on storm surge inJiaojiang Estuary,China 被引量:4
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作者 Zhi-lin Sun Sen-jun Huang +2 位作者 Jian-ge Jiao Hui Nie Mei Lu 《Water Science and Engineering》 EI CAS CSCD 2017年第1期59-69,共11页
Variations in coastline geometry caused by coastal engineering affect tides, storm surges, and storm tides. Three cluster land reclamation projects have been planned for construction in the Jiaojiang Estuary during th... Variations in coastline geometry caused by coastal engineering affect tides, storm surges, and storm tides. Three cluster land reclamation projects have been planned for construction in the Jiaojiang Estuary during the period from 2011 to 2023. They will cause significant changes in coastline geometry. In this study, a surge-tide coupled model was established based on a three-dimensional finite-volume coastal ocean model (FVCOM). A series of numerical experiments were carried out to investigate the effects of variations in coastline geometry on tides, storm surges, and storm tides. This model was calibrated using data observed at the Haimen and Ruian gauge stations and then used to reproduce the tides, storm surges, and storm tides in the Jiaojiang Estuary caused by Typhoon Winnie in 1997. Results show that the high tide level, peak storm surge, and high storm tide level at the Haimen Gauge Station increased along with the completion of reclamation projects, and the maximum increments caused by the third project were 0.13 m, 0.50 m, and 0.43 m, respectively. The envelopes with maximum storm tide levels of 7.0 m and 8.0 m inside the river mouth appeared to move seaward, with the latter shifting 1.8 km, 3.3 km, and 4.4 km due to the first project, second project, and third project, respectively. The results achieved in this study contribute to reducing the effects of, and preventing storm disasters after the land reclamation in the Jiaojiang Estuary. 展开更多
关键词 Cluster land reclamation Coastline geometry variation Storm surge Jiaojiang Estuary Typhoon Winnie
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