Then , the thesis presents a schema based two - level associated model , which dramatically reduces the number of the candidate subscriptions . in addition , an incremental subscription matching algorithm is proposed to efficiently matching events for millions subscriptions . furthermore , since indexing is very important to the system , the indexing scheme for xml data is defined based on the containment relationship , which can be more efficient to deal with relative paths than previous methods 另外，由于在意向匹配过程中涉及大量索引问题，为此针对先前研究在处理基于相对路径的意向表示上存在的问题，本文提出了一种基于相容关系的索引模式，利用系统抽象数据拓扑结构进行相对路径到绝对路径的转换，通过基于相容关系的数字方式编码，能够快速确定对应结点的依赖关系，同时提出了新的路径转换算法，将时间复杂度由过去的平方时间变为线性。
Aim to the special model nc bend tube , use the modeling method that essential parameter drive product sample model ; 3 ) in the foundation that summing up a rule of optimized welding assembly underside of tube , develop the nc bend tube welding underside optimization design tool , then complete the optimization design united with two application methods : rotation method and the least squares method ; 4 ) propose a design method of nc bend tube welding jig bottom base , then establish model storehouse according to the design rules , and endow the foundation model with assembly feature 针对多数通用型数控导管,运用矢量转换算法反求得导管关键特征,并据此创建导管模型,针对特殊造型数控导管,使用关键参数驱动产品库样本模型的方法完成建模; 3 )在归纳总结了焊接底面创建规则的基础上,开发数控导管焊接底面优化设计工具,分别应用旋转法和最小二乘法两类方法完成底面的优化设计; 4 )提出了一种数控导管焊接底座设计方法。
In this paper , the principle of euclidean distance transform based on binary images was demonstrated in detail , and it also introduced the implementation schemes and calculation capabilities of those algorithms for euclidean distance transform which are known . with focus on the practical application , we took some reforms in this paper to implement the distance transform algorithm based on the advantages of previous researches 针对欧几里德距离转换算法的实用性，本文在吸取前人研究成果的基础上，分析了不同算法的实现原理和计算性能，对计算性能最接近实际应用要求的算法，在实现方案上做了相应的改进，提高算法实现电路计算速度和减小其电路规模，从而使基于硬件实现的欧几里德距离转换算法更具有实用性。
At the same time , popular new methods and their latest situation were described . we put forward a new method of bit - stream rate of video - low pass filter and rate control algorithm . this method is easy to be realized and to meet the need of real time comparing with those popular ones , so it has more practical value 文章首先对传统的码率转换算法进行了简单叙述，指出了其弊端，同时讨论了人们为了克服此缺点而提出的各种码率转换算法，论述了当前国内外动态,然后在此基础上提出了一种新的码率转换算法- -低通滤波法，该算法与其它算法相比易于实现，能够满足实时性要求，具有较强的实用价值。
Furthermore , the existing algorithms for dynamic query are generally dependent on the static mapping algorithms . to resolve these two problems , a gvrs ( general virtual relational schema ) model for xml document is put forward as a bridge between xml instance document and factual rdb , and an algorithm which transformes xquery into sql and is independent on the static schema mapping , is realized . based on the above approaches , the dynamic data query on bottom rdb is carried out through xml view and the data integration between rdb and xml is achieved on the dynamic query tier 通过xml视图动态检索底层rdb的技术建立基于rdb的xml动态检索机制；针对现有动态检索算法大多依赖静态模式映射算法的问题以及基于w3c工作草案xquery的研究尚无实质性进展的现状，通过提出并建立gvrs ( generalvirtualrelationalschemaforxmldocument )模型，作为xml事例文件与rdb之间的桥梁，实现了一种与静态模式映射“无关”的xquery到sql的转换算法，保证动态检索对各种静态转换的普遍适应性，实现了通过xml视图对底层rdb的动态数据检索，较好地解决了xml与rdb在动态检索层面的数据集成问题，可有效满足根据用户需要有选择动态检索系统底层rdb数据的需求。
Finally , with the step - by - step scheme , we implemented the fast hardware algorithm for euclidean distance transform based on two - dimension images . our design , compared with previous schemes , has these following advantages : ( 1 ) the calculation speed was accelerated from o ( n3 ) to o ( n2 ) , this make the implementation of euclidean distance transform possible 相比之下，本文所实现的基于硬件的欧几里德转换算法有以下优点：其一，在计算速度方面有很大提高，使其计算速度从o ( n ~ 3 )提高到o ( n ~ 2 ) ，从而使算法具有实用性。
