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基于各种海量规则信息处理的需求,提出了一种海量规则模式匹配方法。设计了海量规则模式匹配方法的基本算法步骤,研究了各种规则节点的匹配处理方法。最后总结了海量规则模式匹配方法的特点。海量规则模式匹配算法部分拓展了现有规则匹配处理模式,提出了新的匹配处理方法。对比结果表明,该方法具有较好的效果。 相似文献
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模式匹配是串处理系统中最重要的操作之一,如何提高匹配效率是关键问题.提出一种基于贪心原理的模式匹配方法,运用最优化原理分析模式的特征值,字符匹配的顺序按照特征值大小进行.基于该思想.根据串相邻字符的相同和相异特征,并利用特征优化以及策略优化,设计了四种实用算法.实验表明贪心匹配方法效率高、适应性好、易于扩展和优化. 相似文献
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GML是基于XML的空间信息编码标准。GML模式匹配技术作为实现应用模式的集成与共享的关键技术,与GML解析机理和实现技术密切相关。本文详细介绍了关于GML模式匹配的概念;给出了匹配方法的步骤、算法及已所实现的模式匹配详细流程,包括语意与结构相似度判断以及权重的设置;最后,对匹配过程中包含的不确定因素进行了分析与讨论。 相似文献
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异构数据源间的模式匹配技术是数据共享应用设计的基本步骤。提出了一种新型的模式匹配方法——基于数据源信息语境的复杂模式匹配方法,它采用考虑数据源的信息语境来计算复杂匹配,能够有效地解决复杂匹配时产生的候选匹配查询空间过大的问题。该方法首先从数据源的信息语境中抽取复杂概念,并将抽取的复杂概念添加到原有数据源中,然后通过模式匹配模块计算数据源间的概念匹配。实验表明,该方法不仅能大大降低候选匹配查询空间的规模,而且能够提高模式匹配的查全率和查准率。 相似文献
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为克服传统的基于细节点匹配的不足,对基于点模式匹配算法与改进的2DPCA匹配算法的混合识别算法进行了改进。改进后的算法在点模式匹配算法中加入改进的2DPCA算法的初匹配得分权重,提高了点模式匹配算法的准确性;并利用点模式匹配算法对2DPCA算法的匹配结果进行二次匹配,同时也提高了2DPCA算法匹配的准确率。 相似文献
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模式匹配技术是数据集成领域中的关键技术。为了快速、准确地完成模式匹配工作,已经提出了大量的基于各种模式类型的模式匹配方法。本文介绍了现存的模式匹配技术和两种多源模式匹配技术;并且为满足大规模匹配的需要提出了一种改进的多源模式匹配算法。 相似文献
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针对Deep Web数据源结果模式信息的匹配问题,提出了一种基于实例的结果模式匹配的方法。该方法能够匹配并验证数据源的结果模式属性信息,同时记录数据在结果页面中的结构信息。利用基于查询请求松弛的两段模式匹配方法精确地匹配模式属性,并基于模式属性间共现度信息来提高属性匹配的查全率和查准率。从实验结果分析可以看出,基于实例的方法能够有效地识别数据源模式信息,提高模式属性查全率和查准率。 相似文献
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A survey of approaches to automatic schema matching 总被引:76,自引:1,他引:75
Erhard Rahm Philip A. Bernstein 《The VLDB Journal The International Journal on Very Large Data Bases》2001,10(4):334-350
Schema matching is a basic problem in many database application domains, such as data integration, E-business, data warehousing,
and semantic query processing. In current implementations, schema matching is typically performed manually, which has significant
limitations. On the other hand, previous research papers have proposed many techniques to achieve a partial automation of
the match operation for specific application domains. We present a taxonomy that covers many of these existing approaches,
and we describe the approaches in some detail. In particular, we distinguish between schema-level and instance-level, element-level
and structure-level, and language-based and constraint-based matchers. Based on our classification we review some previous
match implementations thereby indicating which part of the solution space they cover. We intend our taxonomy and review of
past work to be useful when comparing different approaches to schema matching, when developing a new match algorithm, and
when implementing a schema matching component.
Received: 5 February 2001 / Accepted: 6 September 2001 Published online: 21 November 2001 相似文献
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Schema matching plays a central role in a myriad of XML-based applications. There has been a growing need for developing high-performance matching systems in order to identify and discover semantic correspondences across XML data. XML schema matching methods face several challenges in the form of definition, adoption, utilization, and combination of element similarity measures. In this paper, we classify, review, and experimentally compare major methods of element similarity measures and their combinations. We aim at presenting a unified view which is useful when developing a new element similarity measure, when implementing an XML schema matching component, when using an XML schema matching system, and when comparing XML schema matching systems. 相似文献
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Interoperability of software is a critical requirement in the architecture, engineering, and construction (AEC) industry, where a number of data exchange standards have been created to enable data exchange among different software packages. To be able to comply with existing data exchange standards, the software developers need to match their internal data schemas to the schema defined in a standard and vice versa. The process of matching two large scale data models is time consuming and cumbersome when performed manually, and becomes even more challenging when a source and/or a target model is being updated frequently to meet the ever expanding real world requirements. While several prior studies discussed the need for approaches toward automated or semi-automated schema matching, an approach that builds on existing matches between two models has rarely been studied. In this paper, we present a semi-automated approach for model matching. This approach leverages a given set of existing matching between two models and upgrades those matching when a new version of a target model is released. The paper describes in detail a list of upgrade patterns generated and validated through a prototype by matching a domain-specific data model to several recent releases of the industry foundation classes. 相似文献
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Matching large schemas: Approaches and evaluation 总被引:1,自引:0,他引:1
Current schema matching approaches still have to improve for large and complex Schemas. The large search space increases the likelihood for false matches as well as execution times. Further difficulties for Schema matching are posed by the high expressive power and versatility of modern schema languages, in particular user-defined types and classes, component reuse capabilities, and support for distributed schemas and namespaces. To better assist the user in matching complex schemas, we have developed a new generic schema matching tool, COMA++, providing a library of individual matchers and a flexible infrastructure to combine the matchers and refine their results. Different match strategies can be applied including a new scalable approach to identify context-dependent correspondences between schemas with shared elements and a fragment-based match approach which decomposes a large match task into smaller tasks. We conducted a comprehensive evaluation of the match strategies using large e-Business standard schemas. Besides providing helpful insights for future match implementations, the evaluation demonstrated the practicability of our system for matching large schemas. 相似文献
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Today there are many media sharing applications that use diverse metadata formats to describe media resources. This leads to interoperability issues in cataloguing, searching and annotation. This situation poses schema matching algorithms in the eye of the storm of metadata interoperability. In this paper we present two different solutions for multimedia metadata schema matching using variable linkage algorithms. These methods consist in directly comparing the data values stored in the different metadata variables, allowing to overcome the inherent limitations of schema-level matching approaches. We show the feasibility of these methods through some experiments with real metadata information extracted from the image hosting websites Deviantart, Flickr and Picasa. 相似文献
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Deep Web集成服务的不确定模式匹配 总被引:5,自引:0,他引:5
随着Deep Web的迅猛发展,从高度自治、异构及动态变化的Web数据库中,为用户提供高质量的数据逐渐成为当前Deep Web集成服务的一个研究热点.在大部分Web数据库只能通过查询接口为用户提供服务的前提下,如何建立用户请求与集成查询接口模式之间以及集成查询接口模式与Web数据库查询接口模式之间的匹配关系,是Deep Web集成服务中进行合理的用户请求转换的关键.之前的相关工作都是寻找最佳的匹配结果,回避匹配的不确定性,丢弃了可能有价值的其他匹配结果.文中首先剖析了请求转换中模式匹配的不确定性,提出了数字类型的相似度计算方法,给出了进行数字类型的模式匹配的有效的剪枝方法以及数据类型驱动的模式匹配优化方法,并在此基础上提出了一种基于相似度计算的不确定性模式匹配方法,最后通过大量的实验证明了该方法的有效性. 相似文献
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模式匹配就是在作为输入的模式中有对应语义关系的元素间产生一个映射.为了提高模式匹配的效率,提出了一种新型的模式匹配方法--源模式分裂模式匹配算法.它可以解决标准模式匹配难以解决的问题:1)源模式的某一个属性和多个目标模式的多个属性之间建立匹配关系;2)表格中的不同元组对应其他表格同一元组的不同属性值的匹配.在匹配过程中,该方法先搜索种类型属性,然后根据种类型属性建立选择条件,最后把源模式进行分裂形成视图,再重新生成候选匹配集合,从而提高模式匹配的质量. 相似文献