存档

‘Protégé’ 分类的存档

Protege教程——OWL中类的丰富表达能力

2008年10月23日

这里是Protege教程中一些比较重要的片段,完整教程在http://www.crabone.com/index.php/protege-introduction#more-6

当我们再次回顾创建类的6种方法时,我们可曾反过来想想,如果让我们来设计OWL语言,我们会设计出几类创建类的方法?

这块板是属于木头的——类:木头(名词型)
你是是很有理想的——类:很有理想的(有:动词;理想:名词;属于动宾型)
这个材料既是属于树胶又是属于塑料的——类:树胶∩塑料(名词和名词的集合型)
他是男人——类:男人(名词型)

它是吃肉的。(吃:动词;肉:名词;属于动宾型)
他是有一颗赤诚热心的人——类1∩类2;类1:人(名词型);类二:有一颗赤诚热心的(量词动宾型)
这类皇冠都镶有No.1098型钻石——类:镶有No.1098型钻石的(具体个体的动宾型)
这批货物要么是可乐瓶,要么是啤酒瓶——枚举类:类1和类二

我们会发现,上面的这些类的定义方法, 阅读全文…

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Protege教程——Property Domains and Ranges

2008年10月23日

其实就是一个属性的类型和范围,比如 int i;3<i<10 那么int就是i的domain,range就是3-10。

用英文来形象的表达就是:Properties link individuals from the domain to individuals from the range.

在我们这个Organization的例子中,我们拿hasInterest这个Property来说,它的domain就是Organization,它的Range就是Interest。

注意!Properties的domain,range和Properties的6大特性不一样,6大特性那是一种推理机制要用到的约束——Constraint,而domain,range是一种公理——axiom。什么意思?约束是用来限制的,可以用推理机制来验证,如果限制出了问题就会推理出错。而公理总是对的,推理要基于它们来推理。举个例子,hasTopping的domain我们定义为Pizza,如果在本体上,发现hasTopping连接到了icecream,那么是不会报错的,OWL会认为,icecream为Pizza的子类,这在W3C的文档上有详细的语义推理定义,见下面的公式。除非……你在构建本体的时候强行定义了,icecream和Pizza是相互Disjoint的,见3.5节。

if
T(?p, rdfs:domain, ?c1)

T(?c1, rdfs:subClassOf, ?c2)
then
T(?p, rdfs:domain, ?c2)

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Protege教程——创建OWL Properties

2008年10月23日

这里是Protege教程中一些比较重要的片段,完整教程在http://www.crabone.com/index.php/protege-introduction#more-6

OWL Properties代表了一种关系 relationship,在OWL里,有2种类型的Properties。一种叫Object Properties,代表了individual到individual之间的一种关系。还有一种叫Datatype Properties,代表了individual和基本数据类型的关系,有点像类的属性,比如年龄、身高等。还有一种叫Annotation properties,是属于元数据,数据的数据,可以用来解释Classes、Individual、Object/Datatype Properties。下图以这3种类型,举个例子:

阅读全文…

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Protege教程——DisjointClasses(一个非常重要的公理)

2008年10月23日

这里是Protege教程中一些比较重要的片段,完整教程在http://www.crabone.com/index.php/protege-introduction#more-6

DisjointClasses、SubClassOf、EquivalentClasses是类的三大公理,见下图:

SubClassOf已经在上一节讲过了, 阅读全文…

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Protege教程——创建一棵类的层次树

2008年10月23日

这里是Protege教程中一些比较重要的片段,完整教程在http://www.crabone.com/index.php/protege-introduction#more-6

创建类,有6种方式,在我的OWL入门教程中,有非常详细的阐述,想了解的朋友去看看。
6种创建类的方法
在创建本体的时候,用的最多的当然是第一种方法————Named Class。这种Class也被称为Plain Class,意思就是没有任何语义的类,仅仅是一个标示。好了,我们开始!

阅读全文…

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Protege版本之间的选择

2008年9月25日

用Protege做本体开发,一定要搞清楚Protege的版本,这点很重要。

Protege 3.x Protege 4.0
Frames Support Frames Support
Frames editing supported via the Protege-Frames editor None (Protege-Frames editor has not been migrated yet)
OWL Support OWL Support
OWL 1.0 language support OWL 2.0 language support
OWL and RDF(S) support Pure OWL framework
OWL and RDF(S) files are accessible via the Protege-OWL API. This API layered OWL and RDF support over the existing Frames API. OWL files are accessible via the OWL API, which was developed at the The University Of Manchester (not the Protege-OWL API, which was used in the 3.x series). This is a very clean API that closely follows the OWL specification and the parser is optimized to be faster and use less memory.
SPARQL support No SPARQL support yet
SWRL support No SWRL support yet
Support for meta-modeling (allowing OWL Full) No OWL Full
Reasoner support through HTTP DIG interface allows connection to any DIG compliant reasoner, as well as direct connection to the Pellet reasoner Direct connection to FaCT++ and Pellet for optimum speed of classification
Configuration settings stored in Protege Project files (.pprj) No project files, configuration settings persist across installations of Protege
OWL imports handled through a repository mechanism Simplified imports resolution from a common folder (repositories also supported)
Plugins Plugins
Plugin framework developed at Stanford for tab widgets, slot widgets, back-ends, projects, importing, and exporting Plugin framework was switched to the more industry standard OSGi, which allows for any type of plugin extension
Large set of plugins available, developed both in-house and externally by the Protege community Migration of plugins to Protege 4 is in the beginning stages, but an increasing number are becoming available
User Interface User Interface
Tab and slot widgets make much of user interface configurable Plugins define all user interface elements including tabs, views, and menus making everything configurable
Access is provided to the meta model and can be used to configure the user interface Menu and drag and drop user interface elements
Multi-user Support Multi-user Support
Multiple users can edit the same ontology using the client-server version of Protege None (Protege Client-Server has not been migrated yet)
Database Storage Model Database Storage Model
Ability to store ontologies in a database provided by the JDBC database back-end None (database back-end has not been migrated yet)

初学者常犯的错误就是用protege-owl API来编辑4.0的OWL2.0文件,OWL2.0要用OWL API来编辑。

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