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1.
该文分析Xpath表达式中出现(任意匹配字符)和//(子孙轴)对查询效率的影响,提出用XMLSchema对Xpath表达式进行约束来解决问题,给出实现的核心算法。  相似文献   

2.
曾一  许娴  张元平 《计算机工程》2006,32(18):64-66
XML Schema作为一种描述XML文档模式信息即结构信息的标准,对于XML索引的建立及查询效率的提高有着重要的作用。现有的大部分XML索引结构着重研究XML文档的结构查询,而对于XML文档的更新支持却不多,对无效查询也不能作出快速的判断。该文基于已有的XML文档的编码方式,提出了一种基于Schema的XML索引结构,不仅能支持基于有效性验证的动态更新,使得XML文档和XML Schema保持一致,而且对用户提出的无效的路径查询也能在较短时间内作出判断。  相似文献   

3.
基于模式的XML文档元素的序列化标识   总被引:1,自引:0,他引:1  
在XML文档中,对象的顺序包含语义。为了提高查询和插入操作的效率,对象标识(OID)需要序列化。现在普遍采用的OID序列化方法是前序算法,但是该算法代价很大。该文设计了基于模式的OID序列化算法。算法的核心是OID区间预留,以实例文档的模式和统计信息为基础,将计算机可以表达的整数分成区间,然后将对象映射到区间内,从而给所有对象赋予OID。新算法大大降低了XML文档序列化的开销。  相似文献   

4.
基于Motor Schema的多移动机器人队形优化控制   总被引:3,自引:0,他引:3  
曹志强  王硕  张斌  谭民 《控制与决策》2001,16(Z1):763-765
针对多移动机器人的队形优化控制任务,引入4种基本行为,即奔向目标行为、保持队形行为、避免与静态障碍物碰撞行为、避免与其它机器人碰撞行为.为了实现行为的决策,机器人采用基于MotorSchema的结构,并通过遗传算法优化行为合成所需的控制参数.仿真结果表明,所提出的方法是可行的.  相似文献   

5.
A novel approach to object recognition and scene analysis based on neural network representation of visual schemas is described. Given an input scene, the VISOR system focuses attention successively at each component, and the schema representations cooperate and compete to match the inputs. The schema hierarchy is learned from examples through unsupervised adaptation and reinforcement learning. VISOR learns that some objects are more important than others in identifying the scene, and that the importance of spatial relations varies depending on the scene. As the inputs differ increasingly from the schemas, VISOR's recognition process is remarkably robust, and automatically generates a measure of confidence in the analysis.  相似文献   

6.
7.
C. Barbăro§ie 《Computing》1995,54(4):347-357
When solving ODEs by interval methods, the main difficulty is reducing the wrapping effect. Various solutions have been put forward, all of which are applicable for narrow initial intervals or to particular classes of equations only. This paper describes an algorithm which, instead of intervals, uses a larger family of sets. The algorithm exhibits a very small wrapping effect and applies to any type of equation and initial region. For the time being it handles only two-dimensional equations.  相似文献   

8.
数据加解密、数据封装和数字信封是可信密码模块的三种数据安全保护方式。在可信计算环境下提出了一种数据封装方法。该方法将数据绑定于可信密码模块和特定的平台状态,使得受保护数据只能由特定用户在指定可信计算环境特定的平台状态下才能解密。实验表明,该方法在可信计算环境下以较小的代价实现了数据的封装,保护数据的安全性。  相似文献   

9.
10.
We model developable surfaces by wrapping a planar figure around cones and cylinders. Complicated developables can be constructed by successive mappings using cones and cylinders of different sizes and shapes. We also propose an intuitive control mechanism, which allows a user to select an arbitrary point on the planar figure and move it to a new position. Numerical techniques are then used to find a cone or cylinder that produces the required mapping. Several examples demonstrate the effectiveness of our technique.  相似文献   

11.
Rigorously computed orbits of dynamical systems without the wrapping effect   总被引:2,自引:0,他引:2  
W. Kühn 《Computing》1998,61(1):47-67
A new method for rigorously computing orbits of discrete dynamical systems is introduced. High order zonotope enclosures of the orbit are computed, using only matrix algebra. The wrapping effect can be made arbitrarily small by choosing the order high enough. The method is easy to implement and especially suited for parallel computing. It is compared to other well known strategies, and several examples are given.  相似文献   

12.
The computational grid is rapidly evolving into a service-oriented computing infrastructure that facilitates resource sharing for solving large-scale data and computationally intensive problems. Peer-to-peer (P2P) systems have emerged as an infrastructure enabling technologies for enhanced scalability and reliability in file sharing and content distribution. It is envisioned that P2P enabled service-oriented grid systems would virtualize various resources as services with high scalability and reliability. Many legacy software resources exist nowadays, but making them grid aware services for effective resource sharing has become an issue of vital importance. This paper presents GSLab, a toolkit for automatically wrapping legacy software into services that can be published, discovered and reused in grid environments. GSLab employs Sun Grid Engine (SGE) to enhance its performance in execution of wrapped services. Using GSLab, we have automatically wrapped a legacy computer animation rendering code written in C as a service that can be discovered and accessed in a SGE environment. The evaluation results show that the performance of GSLab improves with an increase in the number of computing nodes involved.
Nick AntonopoulosEmail:
  相似文献   

13.
Wrapping-based informed RRT*, proposed in this paper, combines a size-diminishing procedure, i.e., ‘wrapping procedure’ with informed RRT*, which samples random path nodes within a hyperellipsoid. The major and minor axes of the hyperellipsoid are determined by the initial and final configurations and current best solution’s path cost. Wrapping-based informed RRT* can advance from the first solution acquired by the planner to an improved, feasible solution which can drastically reduce the size of the hyperellipsoid. This leads to much quicker convergence to the optimal value of the path cost, resulting in the minimum action of the robot joints. The algorithm was tested in various environments with different numbers of joint variables and showed much better performance than the existing planners. Furthermore, the wrapping procedure proved to be a comparably insignificant computational burden regardless of the number of dimensions of the configuration space.  相似文献   

14.
Zhao  Zhanfang  Han  SungKook  Kim  JuRi 《Multimedia Tools and Applications》2019,78(20):28835-28851
Multimedia Tools and Applications - The Web of Data used to share and interchange the diverse data of heterogeneous types on the Web has been actively established. Ontology-based Linked Open Data...  相似文献   

15.
Guo  Jianqiao  Huang  Hongshi  Yu  Yuanyuan  Liang  Zixuan  Ambrósio  Jorge  Zhao  Zhihua  Ren  Gexue  Ao  Yingfang 《Multibody System Dynamics》2020,49(3):315-336
Multibody System Dynamics - Skeletal muscles usually wrap over multiple anatomical features, and their mass moves along the curved muscle paths during human locomotion. However, existing...  相似文献   

16.
结合网站内容和结构进行的Web日志挖掘   总被引:7,自引:1,他引:7  
提出一种以聚类为基础的Web日志挖掘方法:从Web日志事务、Web站点内容和Web站点结构3个不同方面来聚类页面集合,并通过将用户的访问记录和页面聚集进行匹配和相关度计算,来预测用户感兴趣的页面。  相似文献   

17.
This paper examines the evolution of the World Wide Web as a network of networks and discusses the emergence of Web Science as an interdisciplinary area that can provide us with insights on how the Web developed, and how it has affected and is affected by society. Through its different stages of evolution, the Web has gradually changed from a technological network of documents to a network where documents, data, people and organisations are interlinked in various and often unexpected ways. It has developed from a technological artefact separate from people to an integral part of human activity that is having an increasingly significant impact on the world. This paper outlines the lessons from this retrospective examination of the evolution of the Web, presents the main outcomes of Web Science activities and discusses directions along which future developments could be anticipated.  相似文献   

18.
19.
Single-walled carbon nanotube (SWCNT) is one of the most popular low-dimensional carbon materials in material science, nanomedicine, and nanoscale electronics. Yet the application of the SWCNTs was hindered by the self-aggregation. To purify and disperse the SWCNTs, non-covalent wrapping is one of the effective options to overcome such defects. In this work, two kinds of short peptides were designed to facilitate the modification of large-diameter SWCNT. The design of the peptide was carried out in a stepwise manner. The effective residues of helix-rich and sheet-rich proteins on SWCNT were studied at the first step, and then a coarse model peptide composed of the key adsorption residues above was built to investigate the adsorption dynamics on SWCNT. In the end, the residues include long alkyl side chain and that include aromatic rings were found to play key roles on the adsorption of protein/peptide on hydrophobic SWCNT. And two peptides rich in the long alkyl chain and aromatic rings were constructed respectively. The predominant adsorption capabilities of the two kinds of peptides were discerned by the adsorption details.  相似文献   

20.
Web Service技术由于其特点和优势,在分布式计算中占有重要地位.本文首先简要描述了跨域不同Web站点一次登录的需求,随后简单介绍了Web Service的原理,最后说明了应用Web Service技术解决一次登录的技术方法.  相似文献   

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