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Multimedia is one of the important communication channels for mankind. Due to the advancement in technology and enormous growth of mankind, a vast array of multimedia data is available today. This has resulted in the obvious need for some techniques for retrieving these data. This paper will give an overview of ontology-based image retrieval system for asteroideae flower family domain. In order to reduce the semantic gap between the low-level visual features of an image and the high-level domain knowledge, we have incorporated a concept of multi-modal image ontology. So, the created asteroideae flower domain specific ontology would have the knowledge about the domain and the visual features. The visual features used to define the ontology are prevalent color, basic intrinsic pattern and contour gradient. In prevalent color extraction, the most dominant color from the images was identified and indexed. In order to determine the texture pattern for a particular flower, basic intrinsic patterns were used. The contour gradients provide the information on the image edges with respect to the image base. These feature values are embedded in the ontology at appropriate slots with respect to the domain knowledge. This paper also defines some of the query axioms which are used to retrieve appropriate information from the created ontology. This ontology can be used for image retrieval system in semantic web.  相似文献   

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提出一种基于本体的图像检索方法。该方法结合特定领域专家知识和对象例图,采用视觉对象本体来描述图像内特定对象的视觉特征,从而构建该领域包含视觉描述的知识库。在检索过程中,利用知识库内的对象的视觉本体描述和目标图像库内的图像低层特征相匹配执行图像检索任务,从而实现在高层次语义上的图像检索。实验结果表明了该方法的有效性和可行性,并在一定程度上缩小了视觉低层特征同图像高层语义的鸿沟。  相似文献   

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基于领域知识的个性化协同商务推荐系统   总被引:1,自引:0,他引:1       下载免费PDF全文
基于领域知识与顾客购买倾向相关联的事实,从知识表示、知识获取、系统实现三个方面研究了个性化协同商务推荐系统的实现策略。知识表示研究了自然语言的本体表示,主要包括:知识本体描述、模糊关系设计、概念关联抽象和公理修正四个部分;知识获取采用多层次领域知识获取和基于数据挖掘的智能知识获取两种方法,对知识的形式化和结构化进行了研究;基于J2EE技术创建了由客户端、服务器端、存储系统组成的协同商务推荐系统的结构模型。最后通过测试网站对系统的有效性进行了验证。  相似文献   

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提出了一种词汇和本体概念间的语义相似度计算方法。该方法利用编辑距离和维基百科从语法和语义两方面综合考虑词汇和概念间的语义相似度。在领域本体的指导下,将方法应用于语义标注过程,建立词汇与本体概念之间的映射。在标注过程中建立知识库,提高算法性能,实验结果说明该方法是行之有效的。  相似文献   

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The paper provides an OWL ontology for legal cases with an instantiation of the legal case Popov v. Hayashi. The ontology makes explicit the conceptual knowledge of the legal case domain, supports reasoning about the domain, and can be used to annotate the text of cases, which in turn can be used to populate the ontology. A populated ontology is a case base which can be used for information retrieval, information extraction, and case based reasoning. The ontology contains not only elements for indexing the case (e.g. the parties, jurisdiction, and date), but as well elements used to reason to a decision such as argument schemes and the components input to the schemes. We use the Protégé ontology editor and knowledge acquisition system, current guidelines for ontology development, and tools for visual and linguistic presentation of the ontology.  相似文献   

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An ontology is a crucial factor for the success of the Semantic Web and other knowledge-based systems in terms of share and reuse of domain knowledge. However, there are a few concrete ontologies within actual knowledge domains including learning domains. In this paper, we develop an ontology which is an explicit formal specification of concepts and semantic relations among them in philosophy. We call it a philosophy ontology. Our philosophy is a formal specification of philosophical knowledge including knowledge of contents of classical texts of philosophy. We propose a methodology, which consists of detailed guidelines and templates, for constructing text-based ontology. Our methodology consists of 3 major steps and 14 minor steps. To implement the philosophy ontology, we develop an ontology management system based on Topic Maps. Our system includes a semi-automatic translator for creating Topic Map documents from the output of conceptualization steps and other tools to construct, store, retrieve ontologies based on Topic Maps. Our methodology and tools can be applied to other learning domain ontologies, such as history, literature, arts, and music.  相似文献   

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Codifying expert domain knowledge is a difficult and expensive task. To evaluate the quality of the outcome, often the same domain expert or a colleague of similar expertise is relied on to undertake a direct evaluation of the knowledge-based system or indirectly by preparing appropriate test data. During an incremental knowledge acquisition process, a data stream is available, and the knowledge base is observed and amended by an expert each time it produces an error. Using the kept record of the system’s performance, we propose an evaluation process to estimate its effectiveness as it gets evolved. We instantiate this process for an incremental knowledge acquisition methodology, Ripple Down Rules. We estimate the added value in each knowledge base update. Using these values, the decision makers in the organisation employing the knowledge-based information system can apply a cost-benefit analysis of the continuation of the incremental knowledge acquisition process. They can then determine when this process, involving keeping an expert online, should be terminated. As a result, the expert is not kept on-line longer than it is absolutely necessary. Hence, a major expense in deploying the information system—the cost of keeping a domain expert on-line—is reduced.  相似文献   

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领域本体提供了丰富的概念集,是领域知识共享的基础。讨论了电子教学系统中课程知识体系的组织与本体表示方法,构造了基于领域本体的知识发现模型,阐述了基于领域概念对相似性的本体映射过程,实现了基于单元知识的电子教学资源的灵活共享。  相似文献   

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中医知识获取是计算机自动实现知识管理、知识重组的前提。中医领域存在大量非结构化知识,难以被深入获取。该文提出一种基于领域本体的知识获取方法,对选取的单一医案中蕴含的知识进行形式化表示,构造中医领域的语义网络,对其进行定量分析,抽取中医领域的概念语义场。实验结果表明,该方法可在一定程度实现中医领域的知识获取。  相似文献   

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陈德彦  赵宏  张霞 《软件学报》2020,31(9):2855-2882
由于本体具有强大的知识表示和推理能力,本体已经在很多领域得到了广泛应用.然而,本体的深入应用还面临着很多深层次的共性语义映问题,已有的本体建模方法仅仅提出了一些简单的指导原则和基本步骤,使得知识工程师仍然无从下手.在基于领域专家知识构建领域语义知识库时,针对领域专家知识中的一词多义、多元关系和安全需求等3类共性语义映射问题,从5个方面展开了深入研究,提出了相应的语义映射方法,总结了10条本体建模约定.最后构建了一个完整的应用案例,并对所提出的5类语义映射方法进行了评价.  相似文献   

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基于开放世界假设和描述逻辑的Web本体语言OWL(Web Ontology Language)是描述分布式、可重用、易扩展的古建筑保护技术领域本体的理想选择。提出一种基于ODM(Ontology Definition Metamodel)模型的本体知识库设计方法,识别古建筑保护领域中的关键概念及其关联关系,建立骨架本体。将关键概念进一步分解,建立对应的子本体,整合子本体形成目标本体。该方法使得古建筑保护领域模型更加直观,以确保分析、设计及实现等阶段模型的一致性。通过实例分析,验证了该方法的可行性和有效性。  相似文献   

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近年来,领域本体作为实现知识共享的基础已应用于视频语义检索。然而,同一或不同应用或领域知识可能存在多个本体,这些本体之间缺乏对术语使用的约定。这种现状所产生的语义不一致性导致难以实现检索过程中的知识推理和互操作过程的自动化,因而严重影响视频检索的效率和结果。提出一个两层本体结构,把同一或不同领域共享或共用的概念与知识映射到一个上层本体,从而解决多本体间语义上的不一致性,实现本体间知识的共享。并通过应用于视频场景的检索实验,说明该方法是有效和可行的。  相似文献   

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模块化是软件工程的一种方法,近年来被引入到本体领域,用以支持本体的重用和本体的整合。已有的工作没有讨论同时含有TBox和ABox的本体知识库的模块化的相关问题。在定义本体知识库的模块和知识库的保守扩充的基础之上,给出了知识库保守扩充的验证算法,并且从理论上证明可用知识库的保守扩充的验证算法来验证一个知识库是否为另外一个知识库的模块。  相似文献   

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《Knowledge》1999,12(1-2):45-54
An ontology defines the terminology of a domain of knowledge: the concepts that constitute the domain, and the relationships between those concepts. In order for two or more knowledge-based systems to interoperate—for example, by exchanging knowledge, or collaborating as agents in a co-operative problem-solving process—they must commit to the definitions in a common ontology. Verifying such commitment is therefore a prerequisite for reliable knowledge-based system interoperability. This article shows how existing knowledge base verification techniques can be applied to verify the commitment of a knowledge-based system to a given ontology. The method takes account of the fact that an ontology will typically be expressed using a different knowledge representation language to the knowledge base, by incorporating translation into the verification procedure. While the representation languages used are specific to a particular project, their features are general and the method has broad applicability.  相似文献   

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李锋 《计算机工程》2012,38(2):85-87
为实现Web 2.0环境下网络知识的获取和共享,提出一种基于案例的知识管理系统。采用案例推理的方法实现知识管理,根据Web 2.0网络环境的特点,在案例表达阶段,为每个案例设置标签属性,使其能实现开放性分类。在案例检索阶段,将领域本体引入相似度的计算。利用人工神经网络算法、用户录入案例标签维护案例库和本体库。实验结果表明,该系统能快速检索出具有较高相似度的历史案例。  相似文献   

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This paper presents the processes of knowledge acquisition and ontology development for structuring the knowledge base of an expert system. Ontological engineering is a process that facilitates construction of the knowledge base of an intelligent system. Ontology is the study of the organization and classification of knowledge. Ontological engineering in artificial intelligence has the practical goal of constructing frameworks for knowledge that allow computational systems to tackle knowledgeintensive problems and it supports knowledge sharing and reuse. To illustrate the process of conceptual modelling using the Inferential Modelling Technique as a basis for ontology construction, the tool and processes are applied to build an expert system in the domain of monitoring of a petroleum-production facility.  相似文献   

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While knowledge-based systems are being used extensively to assist in making decisions, a critical factor that affects their performance and reliability is the quantity and quality of the knowledge bases. Knowledge acquisition requires the design and development of an in-depth comprehension of knowledge modeling and of applicable domain. Many knowledge acquisition tools have been developed to support knowledge base development. However, a weakness that is revealed in these tools is the domain-dependent and complex acquisition process. Domain dependence limits the applicable areas and the complex acquisition process makes the tool difficult to use. In this paper, we present a goal-driven knowledge acquisition tool (GDKAT) that helps elicit and store experts' declarative and procedural knowledge in knowledge bases for a user-defined domain. The designed tool is implemented using the object-oriented design methodology under C++ Windows environment. An example that is used to demonstrate the GDKAT is also delineated. While the application domain for the example presented is reflow soldering in surface mount printed circuit board assembly, the GDKAT can be used to develop knowledge bases for other domains also.  相似文献   

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