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[Semantic Web]rdfs:comment 和 rdfs:label的区别 读书笔记,  科学研究 {{ RDF Primer , 5.4 Other Schema Information For example the rdfs:comment property can be used to provide a human-readable description of a resource. The rdfs:label property can be used to provide a more human-readable version of a resource's name. }} 举例： <rdfs:Class rdf:ID="PowerSystemResource">   <rdfs:label xml:lang="en">PowerSystemResource</rdfs:label>   <rdfs:comment>"A power system component that can be either an     individual element such as a switch or a set of elements     such as a substation. PowerSystemResources that are sets     could be members of other sets. For example a Switch is a     member of a Substation and a Substation could be a member     of a division of a Company"</rdfs:comment> </rdfs:Class>   徐涵（Han Xu） 发表于 2004/12/18 19:31:19 | 阅读全文(3189) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]关于RDF/XML中， rdfs:range的用法 读书笔记,  科学研究 　 {{ RDF Primer  5.2 Describing Properties The rdfs:range property is used to indicate that the values of a particular property are instances of a designated class. For example, if example.org wanted to indicate that the property ex:author had values that are instances of class ex:Person, it would write the RDF statements: ex:Person rdf:type rdfs:Class . ex:author rdf:type rdf:Property . ex:author rdfs:range ex:Person . These statements indicate that ex:Person is a class, ex:author is a property, and that RDF statements using the ex:author property have instances of ex:Person as objects. ...... [snip] ...... The rdfs:range property can also be used to indicate that the value of a property is given by a typed literal, as discussed in Section 2.4. For example, if example.org wanted to indicate that the property ex:age 徐涵（Han Xu） 发表于 2004/12/18 17:02:31 | 阅读全文(2597) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]RDF中使用xml:lang的注意点 读书笔记,  科学研究 http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/ RDF/XML permits the use of the xml:lang attribute as defined by 2.12 Language Identification of XML 1.0 [XML] to allow the identification of content language. The xml:lang attribute can be used on any node element or property element to indicate that the included content is in the given language. Typed literals which includes XML literals are not affected by this attribute. The most specific in-scope language present (if any) is applied to property element string literal content or property attribute values. The xml:lang="" form indicates the absence of a language identifier. http://www.w3.org/TR/2004/REC-rdf-concepts-2 徐涵（Han Xu） 发表于 2004/12/16 18:15:41 | 阅读全文(3390) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]RDF中的数据类型 ： XML Schema Datatypes + rdf:XMLLiteral 读书笔记,  科学研究 RDF中的数据类型由两部分组成：XML Schema built-in Datatypes 及 RDF built-in Datatype -- rdf:XMLLiteral。 {{ RDF uses the datatype abstraction defined by XML Schema Part 2: Datatypes [XML-SCHEMA2], and may be used with any datatype definition that conforms to this abstraction, even if not actually defined in terms of XML Schema. RDF predefines just one datatype rdf:XMLLiteral, used for embedding XML in RDF (see section 5).  }}   {{ // http://www.w3.org/TR/2004/REC-owl-ref-20040210/#rdf-datatype Data values are instances of the RDF Schema class rdfs:Literal. Literals can be either plain (no datatype) or typed. Datatypes are instances of the class rdfs:Datatype. In RDF/XML, the type of a literal is specified by an rdf:datatype attribute of which the value is recommended to be one of the following: A canonical URI reference to an XML Schema datatype of the form: http://www.w3.org/2001/XMLSchema#NAME where "NAME" sh 徐涵（Han Xu） 发表于 2004/12/16 17:36:09 | 阅读全文(2552) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]为什么rdf:predicate 的 range 为 rdfs:Resource,而不是rdf:Property 读书笔记,  科学研究 {{ // RDF Schema Recommendation( http://www.w3.org/TR/2004/REC-rdf-schema-20040210/#ch_predicate ) 5.3.3 rdf:predicate rdf:predicate is an instance of rdf:Property that is used to state the predicate of a statement. A triple of the form: S rdf:predicate P states that S is an instance of rdf:Statement, that P is an instance of rdf:Property and that the predicate of S is P. The rdfs:domain of rdf:predicate is rdf:Statement and the rdfs:range is 徐涵（Han Xu） 发表于 2004/12/12 16:31:03 | 阅读全文(2283) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]About RACER reasoner 读书笔记,  科学研究 {{ // Description Logics for Matchmaking of Services 4.1.2 RACER Reasoner RACER [9, 10] is the rst reasoner for TBox and ABox for the SHIQ logic. It is developed at the Computer Science Department of the University of Hamburg. Like FaCT, it only provides part of the expressiveness that we need for our application. It is able to deal with multiple TBoxes, but they are not interconnected. It does not let us dene a concept in a TBox in terms of concepts or roles from other Tboxes. RACER does not provide support for a dynamic knowledge base as it is not possible to add or remove concepts once the classication has been done. Another interesting feature of RACER is its ability to reason about ABoxes. With our approach to matchmaking this capability is not strictly necessary, as we only need to reason about concepts, for which TBoxes provide the necessary abstraction. However, the ability to reason about ABoxes may prove useful when extending our framework to cover phases of E-Commerce transaction beyond matchmaking. For example, an agreement struck between two parties following matchmaking and automated negotiation [2], needs full instantiation of the parameters that originally appeared in the service descriptions. Support for ABoxes would enable compliance check of the agreement with the negotiation proposals and with the original service descriptions in turn. RACER provides a Java API and allows access to the reason 徐涵（Han Xu） 发表于 2004/12/12 0:54:40 | 阅读全文(3083) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]About FaCT reasoner 读书笔记,  科学研究 {{ // Description Logics for Matchmaking of Services 4.1.1 FaCT Reasoner The FaCT [13] system is a DL classier being developed by Ian Horrocks from the Department of Computer Science at the University of Manchester. It includes two reasoners for TBoxes, one of them for the SHIQ logic. Therefore, it cannot deal with individuals or concrete datatype domains, and a description such as the one in Figure 1 can not be processed with it. To cope with the limitation of SHIQ, we tried to model nominals, datatypes, and datatype values as atomic concepts but this can lead to incorrect inferences [12], not to mention the need to model one atomic concept for each integer. DAML+OIL uses namespaces and import statements to provide extensibility and to deal with the distributed nature of the Web. The support in the reasoner for multiple interconnected TBoxes would solve this problem as we would model each DAML+OIL ontology in a dierent TBox. Because FaCT does not support multiple TBoxes we are using fully qualied names in a single TBox. Moreover, the knowledge base of the matchmaker will change over time by addition of new advertisements as well as deletion or modication of existing ones. FaCT deals with the addition of new classes over time, even after classi- cation has been done, but doesn't provide a mechanism for removing classes in the classication. This is a requirement for our application. One of the main benets 徐涵（Han Xu） 发表于 2004/12/12 0:52:12 | 阅读全文(2369) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web]RDF Validation Service 网上资源,  科学研究 转载自: http://www.w3.org/RDF/Validator/ RDF Validation Service Note: this online service has been updated and now supports the Last Call Working Draft specifications issued by the RDF Core Working Group, including datatypes. Deprecated elements and attributes of the standard RDF Model and Syntax Specification are no longer supported. Online Service Enter a URI or paste an RDF/XML document into the following text field and a 3-tuple (triple) representation of the corresponding data model as well as an optional graphical visualization of the data model will be displayed. <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/"> <rdf:Description rdf:about="http://www.w3.org/"> <dc:title>World Wide Web Consortium</dc:title> </rdf:Description> </rdf:RDF> 徐涵（Han Xu） 发表于 2004/12/9 17:11:23 | 阅读全文(2363) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web][课程主页]語意網與資訊網服務 网上资源,  科学研究 转载自: http://snoopy.cs.nccu.edu.tw/entlab/sematic.htm 語意網與資訊網服務 (Semantic Web and Web Services)   2004年春季班 指導老師：胡毓忠 教授 上課時間： 星期 五< 徐涵（Han Xu） 发表于 2004/12/9 15:28:47 | 阅读全文(3151) | 回复(0) | 编辑 | 精华 | 删除

[Semantic Web][收藏]Recommended readings on Meta-data -- 作者：Da 文章收藏 本文转载自W3CHINA.ORG讨论区(BBS.W3CHINA.ORG)   原文链接 作者：Da 以下为原文： Recommended readings on Meta-data Yesterday I wrote a reply to "急！请问元数据和本体的区别？？" (see that thread's postings for details). As a follow-up here is an article I found very nicely written: http://www.netcrucible.com/semantic.html (Making a Semantic Web by Joshua Allen) Allen starts by discussing a simple case: making use of meta-data to describe webpages so that we can get more information about the contents of those webpages. This leads us, step by step, to the *need* of setting up a rather decentralized pool of such meta-data. I found this way of thinking about the semantic Web closest to my taste: it does not start by describing the "finished" layered cake of the Semantic Web, rather it starts by asking how to use existing tools to make a prototype one (at least in principle). Surely, Allen's article also contains plenty of things that are not that essential to the semantic web (and the article was written 4 years ago). But altogether a very refreshing presentation of the whole picture. Highly recommended, especially to those of us who are quite tired of the "layered pyramid" type of presenting the sem. w 徐涵（Han Xu） 发表于 2004/12/7 20:22:48 | 阅读全文(2431) | 回复(0) | 编辑 | 精华 | 删除

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