A data model applied to the knowledge-based ICAS

Image-guided computer aided surgery system (ICAS) contributes to safeness and success of surgery operations by means of displaying anatomical structures and showing correlative information to surgeons in the process of operation. Based on analysis of requirements for ICAS, a new concept of clinical knowledge-based ICAS was proposed. Designing a reasonable data structure model is essential for realizing this new concept. The traditional data structure is limited in expressing and reusing the clinical knowledge such as locating an anatomical object, topological relations of anatomical objects and correlative clinical attributes. A data structure model called mixed adjacency lists by octree-path-chain (MALOC) was outlined, which can combine patient's images with clinical knowledge, as well as efficiently locate the instrument and search the objects' information. The efficiency of data structures was analyzed and experimental results were given in comparison to other traditional data structures. The result of the nasal surgery experiment proves that MALOC is a proper model for clinical knowledge-based ICAS that has advantages in not only locating the operative instrument precisely but also proving surgeons with real-time operation-correlative information. It is shown that the clinical knowledge-based ICAS with MALOC model has advantages in terms of safety and success of surgical operations, and help in accurately locating the operative instrument and providing operation-correlative knowledge and information to surgeons in the process of operations.     

新型支挡结构在冻土地区的应用

叙述了新型L形支挡结构在多年冻土地区的施工方法和施工步骤,测试分析了挡墙建成后地温的变化情况,结合地温测试试验对冻土上限的变化进行了分析研究.实践证明,L形挡墙是多年冻土地区一种良好的路堑支挡结构.     

L型挡土墙在青藏铁路冻土地区的应用

L型挡土墙是一种新型支挡结构。通过在青藏铁路冻土地区设置试验段，分析了L型挡土墙的预制、施工准备工作、路堑开挖、吊装和回填、整坡等施工工序并提出施工要求。综合分析L型挡土墙现场地温测试试验所得数据资料，得出冻土融化深度变化的基本规律。L型挡土墙具有劳动强度低、对生态环境破坏少、运输吊装方便等优点，便于机械化施工，满足高原冻土地区气候环境恶劣的施工要求。     

卸载后弧线型地道基坑围护的施工分析

深基坑工程一般通过大面积卸载施工区域上皮土方,来缩减基坑开挖深度,进而减少基坑围护工程量,以达到节约施工成本的目的。以虹桥综合交通枢纽内规划EW二路穿越京沪高铁段的地下通道基坑工程卸载施工为对象,总结和分析了在有条件进行场地卸载的情况下,优化弧线型基坑围护施工方案时,需要在地基加固处理、工序施工顺序、施工测量等几方面应注意的事项,供同行参考。     

浅析悬臂式挡土墙在多年冻土区路堑工程中的适应性

根据悬臂式挡墙自身的结构特点,结合多年冻土的物理力学特性以及其地处高原所存在的施工问题,分析了该型挡墙在多年冻土区路堑边坡支挡处理中的优越性,指出该型挡墙是多年冻土区路堑支挡结构的首选类型。