A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the applicatio...A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the application of these 2D casting process CAD systems in foundry enterprises are restricted because they have several deficiencies, such as being overly dependent on the AutoCAD system, and some part files based on PDF format can not be opened directly. To overcome these deficiencies, for the first time an innovative 2D casting process CAD system based on PDF and image format file has been proposed, which breaks through the traditional research and application notion of the 2D casting process CAD system based on AutoCAD. Several key technologies of this system such as coordinate transformation, CAD interactive drawing, file storage, PDF and image format files display, and image recognition technologies were described in detail. A practical 2D CAD casting process system named HZCAD2D(PDF) was developed, which is capable of designing and drawing the casting process on the part drawing based on the PDF format directly, without spending time on drawing the part produced by AutoCAD system. Finally, taking two actual castings as examples, the casting processes were drawn using this system, demonstrating that this system can significantly shorten the cycle of casting process designing.展开更多
PDF格式在电子学术文献出版发行领域占有极其重要的地位,但因其复杂的技术规则,使得PDF无法直接被机器阅读,给针对学术文献的研究工作造成了诸多不便。本文提出了一种基于机器视觉的PDF文档结构识别方法,该方法针对常见的PDF学术论文,将...PDF格式在电子学术文献出版发行领域占有极其重要的地位,但因其复杂的技术规则,使得PDF无法直接被机器阅读,给针对学术文献的研究工作造成了诸多不便。本文提出了一种基于机器视觉的PDF文档结构识别方法,该方法针对常见的PDF学术论文,将PDF文件中的视觉对象和文本对象进行映射,获得内容对象的几何属性和文本属性,并辅以启发式算法对内容对象进行类型判断,得到PDF文档的物理结构和逻辑结构。该方法以直观的方式克服了其他PDF解析方法需要大量人工特征构建或大规模语料训练、难以识别公式表格等缺点,并成功地对ACL (Association for Computational Linguistics)的论文集进行了结构识别和全文抽取。展开更多
基金financially supported by the Program for New Century Excellent Talents in University (No.NCET-09-0396)the National Science&Technology Key Projects of Numerical Control (No.2012ZX04012-011)the Fundamental Research Funds for the Central Universities (2014-IV-016)
文摘A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the application of these 2D casting process CAD systems in foundry enterprises are restricted because they have several deficiencies, such as being overly dependent on the AutoCAD system, and some part files based on PDF format can not be opened directly. To overcome these deficiencies, for the first time an innovative 2D casting process CAD system based on PDF and image format file has been proposed, which breaks through the traditional research and application notion of the 2D casting process CAD system based on AutoCAD. Several key technologies of this system such as coordinate transformation, CAD interactive drawing, file storage, PDF and image format files display, and image recognition technologies were described in detail. A practical 2D CAD casting process system named HZCAD2D(PDF) was developed, which is capable of designing and drawing the casting process on the part drawing based on the PDF format directly, without spending time on drawing the part produced by AutoCAD system. Finally, taking two actual castings as examples, the casting processes were drawn using this system, demonstrating that this system can significantly shorten the cycle of casting process designing.
文摘PDF格式在电子学术文献出版发行领域占有极其重要的地位,但因其复杂的技术规则,使得PDF无法直接被机器阅读,给针对学术文献的研究工作造成了诸多不便。本文提出了一种基于机器视觉的PDF文档结构识别方法,该方法针对常见的PDF学术论文,将PDF文件中的视觉对象和文本对象进行映射,获得内容对象的几何属性和文本属性,并辅以启发式算法对内容对象进行类型判断,得到PDF文档的物理结构和逻辑结构。该方法以直观的方式克服了其他PDF解析方法需要大量人工特征构建或大规模语料训练、难以识别公式表格等缺点,并成功地对ACL (Association for Computational Linguistics)的论文集进行了结构识别和全文抽取。
