Question

我有一些有实例的猫头鹰类。这些类还具有对每个实例都有价值的属性。我已经通过Protege3.4创建了我的本体，并由Rowlex从他们那里创建了c＃库例如，“Program”类具有“Software”和“atGrade”属性的实例。此实例的属性值为“PHD”（atGrade是将域映射到Grade类的对象属性）。这是OWL：

<owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Program">
    <rdfs:subClassOf rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Student"/>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Teacher"/>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Rank"/>
    <rdfs:subClassOf>
        <owl:Restriction>
            <owl:onProperty>
                <owl:ObjectProperty rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#atGrade"/>
            </owl:onProperty>
            <owl:allValuesFrom rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Grade"/>
        </owl:Restriction>
    </rdfs:subClassOf>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Course"/>
    <owl:disjointWith>
        <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#LearningResource"/>
    </owl:disjointWith>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Note"/>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#ClassOfCourse"/>
    <owl:equivalentClass>
        <owl:Class>
            <owl:oneOf rdf:parseType="Collection">
                <Program rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Management">
                    <atGrade rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#PHD"/>
                </Program>
                <Program rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Literature">
                    <atGrade rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#PHD"/>
                </Program>
                <Program rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Software">
                    <atGrade rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#MasterOfResearch"/>
                </Program>
                <Program rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Information_Technology">
                    <atGrade rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#MasterOfScience"/>
                </Program>
            </owl:oneOf>
        </owl:Class>
    </owl:equivalentClass>
    <owl:disjointWith>
        <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Project"/>
    </owl:disjointWith>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Grade"/>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#ResourceType"/>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Language"/>
    <rdfs:comment xml:lang="en">Study branch in which the members are working (e.g. MBA)</rdfs:comment>
    <owl:disjointWith>
        <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Discussion"/>
    </owl:disjointWith>
    <owl:disjointWith rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Question"/>
</owl:Class>

atGrade属性也在本体中定义：

<owl:ObjectProperty rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#atGrade">
    <rdfs:range rdf:resource="http://www.owl-ontologies.com/Ontology1243411901.owl#Grade"/>
    <rdfs:domain>
        <owl:Class>
            <owl:unionOf rdf:parseType="Collection">
                <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Program"/>
                <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Teacher"/>
                <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Project"/>
                <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Course"/>
                <owl:Class rdf:about="http://www.owl-ontologies.com/Ontology1243411901.owl#Student"/>
            </owl:unionOf>
        </owl:Class>
    </rdfs:domain>
</owl:ObjectProperty>

现在当我在c＃中创建其中一个实例时，例如：

Program prog = new Program("http://www.owl-ontologies.com/Ontology1243411901.owl#Management", new RdfDocument());

atGrade属性返回null。我做了以下，但问题没有解决：
- 制作全班（新节目_（...））
- 输入现有的RDF文件：新程序（uri，new RdfDocument（uri）） - 从本体中删除'rdfs：subClassOf'标签。

有什么想法可以解决这个问题吗？也许我应该从本体中删除实例并将它们插入到RDF中，然后从那里检索它们？

Answer 1

您在本体中规定个人遵守您的计划课程。如果一个人的URI是您列举的URI之一并且它具有适当的atGrade属性，那么该个人就是“程序”。

当您创建RdfDocument并创建一个新的Program实例时，您将获得的所有内容都是“myUri typeof Program”。 ROWLEX不会填写默认值并按预期添加额外的atGrade属性。这就是您在检索属性时获得null的原因。您需要将atGrade属性添加到个人，否则它甚至不是有效的程序实例。

检索OWL类实例的属性值时出现问题

1 个答案: