Evaluation of two heuristic approaches to solve the ontology meta-matching problem

Nowadays many techniques and tools are available for addressing the ontology matching problem, however, the complex nature of this problem causes existing solutions to be unsatisfactory. This work aims to shed some light on a more flexible way of matching ontologies. Ontology meta-matching, which is a set of techniques to configure optimum ontology matching functions. In this sense, we propose two approaches to automatically solve the ontology meta-matching problem. The first one is called maximum similarity measure, which is based on a greedy strategy to compute efficiently the parameters which configure a composite matching algorithm. The second approach is called genetics for ontology alignments and is based on a genetic algorithm which scales better for a large number of atomic matching algorithms in the composite algorithm and is able to optimize the results of the matching process.     

一种基于RDF图的本体匹配方法

本体匹配是建立两个本体之间映射关系的过程,一个高效、严格的相似度计算方法是本体匹配的前提条件,为此提出了一种基于RDF图匹配的方法。该方法用RDF图表示本体,使本体间的匹配问题转化为RDF图的匹配问题,并利用匹配树表示匹配的状态,通过匹配树计算出两个本体中各实体之间的相似度,进而得到两个本体之间的映射关系。实验结果表明,该方法在查全率和查准率方面都有很好的表现。     

Ontology selection ranking model for knowledge reuse

Ontology reuse is recommended as a key factor to develop cost-effective and high-quality ontologies because it could reduce development costs by avoiding rebuilding existing ontologies. Selecting the desired ontology from existing ontologies is essential for ontology reuse. Until now, much research on ontology selection has focused on lexical-level support. However, in these cases, it is almost impossible to find an ontology that includes all the concepts matched by the search terms at the semantic level. Finding an ontology that meets users’ needs requires a new ontology selection and ranking mechanism based on semantic similarity matching. We propose an ontology selection and ranking model consisting of selection standards and metrics based on better semantic matching capabilities. The model we propose presents two novel features different from previous research models. First, it enhances the ontology selection and ranking method practically and effectively by enabling semantic matching of taxonomy or relational linkage between concepts. Second, it identifies what measures should be used to rank ontologies in the given context and what weight should be assigned to each selection measure.     

A segment-based approach for large-scale ontology matching

The most ground approach to solve the ontology heterogeneous problem is to determine the semantically identical entities between them, so-called ontology matching. However, the correct and complete identification of semantic correspondences is difficult to achieve with the scale of the ontologies that are huge; thus, achieving good efficiency is the major challenge for large- scale ontology matching tasks. On the basis of our former work, in this paper, we further propose a scalable segment-based ontology matching framework to improve the efficiency of matching large-scale ontologies. In particular, our proposal first divides the source ontology into several disjoint segments through an ontology partition algorithm; each obtained source segment is then used to divide the target ontology by a concept relevance measure; finally, these similar ontology segments are matched in a time and aggregated into the final ontology alignment through a hybrid Evolutionary Algorithm. In the experiment, testing cases with different scales are used to test the performance of our proposal, and the comparison with the participants in OAEI 2014 shows the effectiveness of our approach.     

Ontology learning: state of the art and open issues

Ontology is one of the fundamental cornerstones of the semantic Web. The pervasive use of ontologies in information sharing and knowledge management calls for efficient and effective approaches to ontology development. Ontology learning, which seeks to discover ontological knowledge from various forms of data automatically or semi-automatically, can overcome the bottleneck of ontology acquisition in ontology development. Despite the significant progress in ontology learning research over the past decade, there remain a number of open problems in this field. This paper provides a comprehensive review and discussion of major issues, challenges, and opportunities in ontology learning. We propose a new learning-oriented model for ontology development and a framework for ontology learning. Moreover, we identify and discuss important dimensions for classifying ontology learning approaches and techniques. In light of the impact of domain on choosing ontology learning approaches, we summarize domain characteristics that can facilitate future ontology learning effort. The paper offers a road map and a variety of insights about this fast-growing field.     

Using Bayesian decision for ontology mapping

Ontology mapping is the key point to reach interoperability over ontologies. In semantic web environment, ontologies are usually distributed and heterogeneous and thus it is necessary to find the mapping between them before processing across them. Many efforts have been conducted to automate the discovery of ontology mapping. However, some problems are still evident. In this paper, ontology mapping is formalized as a problem of decision making. In this way, discovery of optimal mapping is cast as finding the decision with minimal risk. An approach called Risk Minimization based Ontology Mapping (RiMOM) is proposed, which automates the process of discoveries on 1:1, n:1, 1:null and null:1 mappings. Based on the techniques of normalization and NLP, the problem of instance heterogeneity in ontology mapping is resolved to a certain extent. To deal with the problem of name conflict in mapping process, we use thesaurus and statistical technique. Experimental results indicate that the proposed method can significantly outperform the baseline methods, and also obtains improvement over the existing methods.     

On-the-fly repair of structural and lexical ontology mismatches in multi-agent systems

In a Semantic-Web-like multi-agent environment, ontology mismatch is inevitable: we can’t realistically expect agents created at different times and places by different people to commit to one unchanging universal ontology. Ontology matching seems to be the only solution to such a problem. However, standard techniques for aligning heterogeneous ontologies are based on time-consuming, off-line and often semi-automated processes and pre-suppose full access to the interacting agents’ ontologies. This is far from ideal in situations where agents meet for the first time, interact quickly and have restricted access to other agents’ private information. In this paper we present the Ontology Repair System (ORS), which attempts to match fully-fledged first-order ontologies automatically using incomplete information. Particular emphasis is laid on its semantic matching module, the Semantic Matcher, which provides a solution for lexical mismatches, which are the most common and the most challenging to address. ORS and the Semantic Matcher have been implemented and evaluated, with very promising results.     

基于关联规则的本体相似度综合计算方法

目前较为流行的最小风险的本体映射(RiMOM)框架通过采用“多策略”的思想虽然取得了一定的效果,但其框架比较臃肿庞杂,且采用的计算结构相似度的选择策略存在一定的局限性。针对上述问题,提出一种基于关联规则的本体相似度综合计算方法。首先,构造关联规则的结构“树”模型,得出相应事务集;其次,进行关联规则的挖掘,根据关联规则计算概念结构的相似性;然后,计算概念的实例、属性、名称的相似度;最后,对多个特征相似度进行综合加权处理,实现本体相似度的最优计算。实验结果表明,该方法较RiMOM在查全率、查准率方面均有较大提高;同时该方法省去了策略选择的步骤,有效降低了时间复杂度。     

A Compact Co-Evolutionary Algorithm for sensor ontology meta-matching

With the proliferation of sensors, semantic web technologies are becoming closely related to sensor network. The linking of elements from semantic web technologies with sensor networks is called semantic sensor web whose main feature is the use of sensor ontologies. However, due to the subjectivity of different sensor ontology designer, different sensor ontologies may define the same entities with different names or in different ways, raising so-called sensor ontology heterogeneity problem. There are many application scenarios where solving the problem of semantic heterogeneity may have a big impact, and it is urgent to provide techniques to enable the processing, interpretation and sharing of data from sensor web whose information is organized into different ontological schemes. Although sensor ontology heterogeneity problem can be effectively solved by Evolutionary Algorithm (EA)-based ontology meta-matching technologies, the drawbacks of traditional EA, such as premature convergence and long runtime, seriously hamper them from being applied in the practical dynamic applications. To solve this problem, we propose a novel Compact Co-Evolutionary Algorithm (CCEA) to improve the ontology alignment’s quality and reduce the runtime consumption. In particular, CCEA works with one better probability vector (PV) \(PV_{better}\) and one worse PV \(PV_{worse}\), where \(PV_{better}\) mainly focuses on the exploitation which dedicates to increase the speed of the convergence and \(PV_{worse}\) pays more attention to the exploration which aims at preventing the premature convergence. In the experiment, we use Ontology Alignment Evaluation Initiative (OAEI) test cases and two pairs of real sensor ontologies to test the performance of our approach. The experimental results show that CCEA-based ontology matching approach is both effective and efficient when matching ontologies with various scales and under different heterogeneous situations, and compared with the state-of-the-art sensor ontology matching systems, CCEA-based ontology matching approach can significantly improve the ontology alignment’s quality.     

ADOL: a novel framework for automatic domain ontology learning

Ontology, as a semantic representation of a shared conceptualization, makes knowledge machine-readable and easy to spread. One of its typical applications is used to develop e-learning systems with Educational Ontology. Ontology can help students master knowledge architecture of required subjects and make scattered courseware more systematic. A big challenge is how to construct Educational Ontology to describe systematic knowledge of different subjects automatically. Currently, most of the ontologies are developed and extended manually, which requires the developers to possess certain professional knowledge and is time-consuming. In this paper, a framework to construct and extend Educational Ontology automatically is proposed.2 The proposed ontology learning framework, called ‘ADOL,’ can convert domain textbooks into a corresponding ontology automatically and efficiently. A case study on High School Physics shows that our approach is feasible and efficient.

     

Reasoning of fuzzy relational databases with fuzzy ontologies

A significant interest developed regarding the problem of describing databases with expressive knowledge representation techniques in recent years, so that database reasoning may be handled intelligently. Therefore, it is possible and meaningful to investigate how to reason on fuzzy relational databases (FRDBs) with fuzzy ontologies. In this paper, we first propose a formal approach and an automated tool for constructing fuzzy ontologies from FRDBs, and then we study how to reason on FRDBs with constructed fuzzy ontologies. First, we give their respective formal definitions of FRDBs and fuzzy Web Ontology Language (OWL) ontologies. On the basis of this, we propose a formal approach that can directly transform an FRDB (including its schema and data information) into a fuzzy OWL ontology (consisting of the fuzzy ontology structure and instance). Furthermore, following the proposed approach, we implement a prototype construction tool called FRDB2FOnto. Finally, based on the constructed fuzzy OWL ontologies, we investigate how to reason on FRDBs (e.g., consistency, satisfiability, subsumption, and redundancy) through the reasoning mechanism of fuzzy OWL ontologies, so that the reasoning of FRDBs may be done automatically by means of the existing fuzzy ontology reasoner.© 2012 Wiley Periodicals, Inc.     

一个基于语义模块的交互式本体匹配框架

本体匹配是用来解决异质本体间互操作问题的一种技术手段。目前,大多数关于本体匹配的研究都集中在了如何提高匹配结果的质量上。然而,一方面,在许多情况下,匹配结果的正确与否直接依赖于用户的判断,另一方面,由于一些描述现实世界的本体十分庞大,匹配工具往往不能及时为用户提供可供确认的匹配对。为此,提出了一种基于语义模块的交互式本体匹配框架。借助信息论的相关知识,将本体聚类成语义模块。用户利用模块核心结点信息对模块的内容进行推断,从而将大规模的本体匹配任务转换为数个规模较小的语义模块间的匹配任务。通过合理地增大用户在匹配过程中的作用,试图在保证匹配质量的同时提高匹配效率。已获得的实验结果表明该方法能显著提高本体匹配任务的效率。     

Trust‐annotated ontology integration using social modelling*

Abstract: As ontologies become more prevalent for information management the need to manage the ontologies increases. Multiple organizations, within a domain, often combine to work on specific projects. When separate organizations come together to communicate, an alignment of terminology and semantics is required. Ontology creation is often privatized for these individual organizations to represent their view of the domain. This creates problems with alignment and integration, making it necessary to consider how much each ontology should influence the current decision to be made. To assist with determining influence a trust‐based approach on authors and their ontologies provides a mechanism for ranking reasoning results. A representation of authors and the individual resources they provide for the merged ontology becomes necessary. The authors are then weighted by trust and trust for the resources they provide the ontology is calculated. This is then used to assist the integration process allowing for an evolutionary trust model to calculate the level of credibility of resources. Once the integration is complete semantic agreement between ontologies allows for the revision of the authors' trust.     

Ontology Integration: Approaches and Challenging Issues

In recent years, the decentralized development of ontologies has led to the generation of multiple ontologies of overlapping knowledge. This heterogeneity problem can be tackled by integrating existing ontologies to build a single coherent one. Ontology integration has been investigated during the last two decades, but it is still a challenging task. In this article, we provide a comprehensive survey of all ontology integration aspects. We discuss related notions and scrutinize existing techniques and literature approaches. We also detail the role of ontology matching in the ontology integration process. Indeed, the ontology community has adopted the splitting of the ontology integration problem into matching, merging and repairing sub-tasks, where matching is a necessary preceding step for merging, and repairing can be included in the matching process or performed separately. Ontology matching and merging systems have become quite proficient, however the trickiest part lies in the repairing step. We also focus on the case of a holistic integration of multiple heterogeneous ontologies, which needs further exploration. Finally, we investigate challenges, open issues, and future directions of the ontology integration and matching areas.     

Optimizing ontology alignment through Memetic Algorithm based on Partial Reference Alignment

All the state of the art approaches based on evolutionary algorithm (EA) for addressing the meta-matching problem in ontology alignment require the domain expert to provide a reference alignment (RA) between two ontologies in advance. Since the RA is very expensive to obtain especially when the scale of ontology is very large, in this paper, we propose to use the Partial Reference Alignment (PRA) built by clustering-based approach to take the place of RA in the process of using evolutionary approach. Then a problem-specific Memetic Algorithm (MA) is proposed to address the meta-matching problem by optimizing the aggregation of three different basic similarity measures (Syntactic Measure, Linguistic Measure and Taxonomy based Measure) into a single similarity metric. The experimental results have shown that using PRA constructed by our approach in most cases leads to higher quality of solution than using PRA built in randomly selecting classes from ontology and the quality of solution is very close to the approach using RA where the precision value of solution is generally high. Comparing to the state of the art ontology matching systems, our approach is able to obtain more accurate results. Moreover, our approach’s performance is better than GOAL approach based on Genetic Algorithm (GA) and RA with the average improvement up to 50.61%. Therefore, the proposed approach is both effective.     

语义集成中的不确定性本体映射模型

语义Web的高速发展使其具有动态性和异构性特征,解决语义信息的异构性问题成为实现信息集成的关键。本体作为一种语义Web的知识表示形式,增强了Web的语义信息。因此,为了解决语义异构性,实现数据间的互操作,必须建立异构本体间的映射关系。然而,为庞大的异构本体建立完全精确的本体映射是不现实的,本体映射中存在一定的不确定性。提出了一种新型的本体映射框架——语义集成中的不确定性本体映射。从不同方面研究本体特征,集合了多种映射策略,并引入了各映射策略中不确定性匹配的解决方案。实验证明,该方法具有可靠的实验性能,并且具有很好的通用性和可扩展性。     

流程可定制本体匹配框架:RiMOM2

本体作为语义Web中的语义表示形式,是语义Web体系结构中的核心元素,是实现知识共享、协同工作的关键。然而现实世界中本体自身与生俱来的分布性和异构性,又极大地限制了数据的共享与集成。为了实现知识的共享、数据的集成,近年来针对本体匹配方法的研究得到了广泛的重视。随着本体匹配研究的深入,许多有效的本体匹配方法被提出。RiMOM2正是一种集成了多种有效本体匹配方法的多策略本体匹配框架。它尽可能地向初级用户隐藏不必要的阂值设定和参数设置,而向高级用户提供匹配流程的可定制功能,以期针对不同用户实现一种既能适用于普遍本体匹配任务,操作简易,又能达到具有针对性匹配效果的本体匹配工具。同时该框架具有匹配方法组件的易扩展性。     

语义Web中的本体匹配研究

随着本体应用的快速发展,本体数量大幅增长,这些本体描述的内容存在重复和关联,但在本体模式上却表现各异。本体匹配旨在识别异构本体中存在语义关联的实体,并建立它们之间匹配关系。它对于消除本体异构、实现本体集成和数据融合等具有重要作用。形式化定义了语义Web中的本体匹配问题,并从本体匹配方法、本体匹配挑战和本体匹配原型系统3个方面调研了最新研究进展,旨在为进一步研究指明方向。