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我正在使用值限制从其值信息中派生实例类型:

:SpaceMission rdf:type owl:Class .

:shuttleUsed rdf:type owl:ObjectProperty ;         
             rdfs:domain :SpaceMission .

:Apollo11 rdf:type owl:NamedIndividual .

:Mission11 rdf:type :SpaceMission , owl:NamedIndividual ;           
           :shuttleUsed :Apollo11 .

:ApolloMission rdf:type owl:Class ;               
               owl:equivalentClass [ rdf:type owl:Class ;
                                     owl:intersectionOf ( :SpaceMission
                                                          [ rdf:type owl:Restriction ;
                                                            owl:onProperty :shuttleUsed ;
                                                            owl:hasValue :Apollo11
                                                          ]
                                                        )
                                   ] .

单值限制owl:hasValue工作正常,:Mission11返回类型的 SPARQL :SpaceMission 和:ApolloMission预期的一样。然后我为类的定义添加第二个值限制:ApolloMission

:Apollo13 rdf:type owl:NamedIndividual .

:ApolloMission rdf:type owl:Class ;
               owl:equivalentClass [ rdf:type owl:Class ;
                                     owl:intersectionOf ( :SpaceMission
                                                          [ rdf:type owl:Restriction ;
                                                            owl:onProperty :shuttleUsed ;
                                                            owl:someValuesFrom [ rdf:type owl:Class ;
                                                                                 owl:oneOf ( :Apollo11
                                                                                             :Apollo13
                                                                                           )
                                                                               ]
                                                          ]
                                                        )
                                   ] .

(限制类型已自动从 更改owl:hasValueowl:someValuesFrom)。在这种情况下,不会返回:ApolloMission个人的预期类型推断:Mission11,而只会返回:SpaceMission. 我有什么问题吗?或者类型推断只能通过类型的值限制来实现owl:hasValue

我正在使用 Jena 的OWLMicroReasoner并为 {<:Mission11> a ?type}. 也许它无法从owl:someValuesFrom限制中推断出来。正如我所说,owl:hasValue限制确实适用于耶拿的微推理器。Jena 的内置推理器是否支持该owl:someValuesFrom限制?

4

1 回答 1

1

如果您可以提供我们可以用于测试的整个本体,通常会更有帮助。这个不是太大,所以重建起来并不难。无论如何,我已经复制了它,它包含在这个答案的末尾。

推理在 OWL 中有效

您正在寻找的推理在 OWL 中是有效的,我们可以通过使用逻辑上完整的 OWL 推理器(例如 Pellet)来看到这一点。我们将在 Protégé 中看到这一点(但您也可以将 Pellet 与 Jena 一起使用。)这是在 Protégé 中重新创建的本体的样子:

Protege 中的重要类公理

Protege 中的重要对象属性公理

然后,当我们启用 Pellet 推理器并请求ApolloMission的实例时,我们得到Mission11,正如预期的那样:

ApolloMission 以 Mission11 为例

既然您说您要询问Mission11的类型,也许您使用了类似询问超类{Mission11}的查询。这也会产生预期的类:

Mission11 具有预期的类型

复制本体

@prefix :      <http://stackoverflow.com/q/21223545/1281433/space.owl#> .
@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl:   <http://www.w3.org/2002/07/owl#> .
@prefix xsd:   <http://www.w3.org/2001/XMLSchema#> .
@prefix rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix space: <http://stackoverflow.com/q/21223545/1281433/space.owl#> .

<http://stackoverflow.com/q/21223545/1281433/space.owl>
        a       owl:Ontology .

space:Mission11  a         owl:NamedIndividual , space:SpaceMission ;
        space:shuttleUsed  space:Apollo11 .

space:shuttleUsed  a  owl:ObjectProperty ;
        rdfs:domain  space:SpaceMission .

space:Apollo13  a  owl:Thing , owl:NamedIndividual .

space:ApolloMission  a       owl:Class ;
        owl:equivalentClass  [ a                   owl:Class ;
                               owl:intersectionOf  ( space:SpaceMission [ a                   owl:Restriction ;
                                                                          owl:onProperty      space:shuttleUsed ;
                                                                          owl:someValuesFrom  [ a          owl:Class ;
                                                                                                owl:oneOf  ( space:Apollo13 space:Apollo11 )
                                                                                              ]
                                                                        ] )
                             ] .

space:SpaceMission  a  owl:Class .

space:Apollo11  a  owl:Thing , owl:NamedIndividual .

为什么耶拿的推理器没有得到一些结果

Jena 的推理并不完整。这并不意味着它们还没有完成。Complete 是形式推理中的一个技术术语,描述推理器(或算法等),这意味着根据推理器不会产生的语言语义存在正确的推理。Jena 的推理器不完整的原因与实施策略(使用基于规则的推理器)和效率考虑有关(我们可以接受速度和我们可以获得的推理之间的权衡)。

有关 Jena 推理器的更多信息,您应该查看Reasoners 和规则引擎:文档中的 Jena 推理支持。正如它所说,它并不完全是最新的,例如:

Jena OWL 推理器不支持超出 OWL/lite 的关键结构是补全和 oneOf。如上所述,对 unionOf 的支持是部分的(由于基于规则的方法的限制),但对于遍历类层次结构很有用。

但正如下面的代码所示,事实上owl:oneOf在一些推理器中支持,所以一些推理器可以做出你想要的 ApolloMission 推理。

Jena 提供了许多推理器,获取连接到它们的 OntModel 的最简单方法是使用在 OntModelSpec 中声明的静态 OntModelSpecs。以下 Java 代码显示,使用您提供的最终本体,不同的推理器提供不同的结果。(用于获取不同 OntModelSpecs 的反射代码有点骇人听闻,但举个简单的例子,这很好。)该代码为每个以“OWL_”开头的声明规范构造一个 OntModel,并针对它们运行查询。

import java.lang.reflect.Field;

import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.ResultSetFormatter;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;

public class JenaReasonersSpaceExample {
    private final static String QUERY =
            "PREFIX : <http://stackoverflow.com/q/21223545/1281433/space.owl#>\n" +
            "select ?type where {\n" +
            "  :Mission11 a ?type .\n" + 
            "}\n";

    private final static Model base =
            ModelFactory.createDefaultModel()
            .read( "file:///home/taylorj/tmp/ontologies/space/space.owl" );

    public static void main(final String[] args) throws IllegalArgumentException, IllegalAccessException {
        // Iterate through the fields of OntModelSpec and for each one whose name
        // begins with "OWL_", assume that it's a static field (so that getField
        // can accept null), and that its value is an OntModelSpec (so that we 
        // can cast and create an OntModel with it and the base model).
        // that begin with "OWL_", and assume t
        for ( final Field field : OntModelSpec.class.getFields() ) {
            if ( field.getName().startsWith("OWL_") ) {
                final OntModelSpec spec = (OntModelSpec) field.get(null);
                final OntModel model = ModelFactory.createOntologyModel( spec, base );

                // Run the query against the model (that will use the specified reasoner)
                // and show the field that we used and the results that we get.
                System.out.println( "\n=== "+field.getName()+" ===" );
                ResultSetFormatter.out(QueryExecutionFactory.create(QUERY, model).execSelect());
            }
        }
    }
}

输出如下。一些推理者可以推断 Mission11 是 ApolloMission。这些是规范使用的:OWL_MEM_RULE_INFOWL_MEM_MINI_RULE_INFOWL_DL_MEM_RULE_INFOWL_LITE_MEM_RULES_INF。看起来您可能想要坚持RULE名称中包含的推理器。

=== OWL_MEM ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
------------------------------------------------------------------------

=== OWL_MEM_RDFS_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                      |
------------------------------------------------------------------------

=== OWL_MEM_TRANS_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
------------------------------------------------------------------------

=== OWL_MEM_RULE_INF ===
-------------------------------------------------------------------------
| type                                                                  |
=========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission>  |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                       |
| <http://www.w3.org/2002/07/owl#Thing>                                 |
| _:b0                                                                  |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                       |
| _:b1                                                                  |
| <http://stackoverflow.com/q/21223545/1281433/space.owl#ApolloMission> |
-------------------------------------------------------------------------

=== OWL_MEM_MICRO_RULE_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
| <http://www.w3.org/2002/07/owl#Thing>                                |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                      |
------------------------------------------------------------------------

=== OWL_MEM_MINI_RULE_INF ===
-------------------------------------------------------------------------
| type                                                                  |
=========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission>  |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                       |
| <http://www.w3.org/2002/07/owl#Thing>                                 |
| _:b0                                                                  |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                       |
| _:b1                                                                  |
| <http://stackoverflow.com/q/21223545/1281433/space.owl#ApolloMission> |
-------------------------------------------------------------------------

=== OWL_DL_MEM ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
------------------------------------------------------------------------

=== OWL_DL_MEM_RDFS_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                      |
------------------------------------------------------------------------

=== OWL_DL_MEM_TRANS_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
------------------------------------------------------------------------

=== OWL_DL_MEM_RULE_INF ===
-------------------------------------------------------------------------
| type                                                                  |
=========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission>  |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                       |
| <http://www.w3.org/2002/07/owl#Thing>                                 |
| _:b0                                                                  |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                       |
| <http://stackoverflow.com/q/21223545/1281433/space.owl#ApolloMission> |
| _:b1                                                                  |
-------------------------------------------------------------------------

=== OWL_LITE_MEM ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
------------------------------------------------------------------------

=== OWL_LITE_MEM_TRANS_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
------------------------------------------------------------------------

=== OWL_LITE_MEM_RDFS_INF ===
------------------------------------------------------------------------
| type                                                                 |
========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission> |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                      |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                      |
------------------------------------------------------------------------

=== OWL_LITE_MEM_RULES_INF ===
-------------------------------------------------------------------------
| type                                                                  |
=========================================================================
| <http://stackoverflow.com/q/21223545/1281433/space.owl#SpaceMission>  |
| <http://www.w3.org/2002/07/owl#NamedIndividual>                       |
| <http://www.w3.org/2002/07/owl#Thing>                                 |
| _:b0                                                                  |
| <http://www.w3.org/2000/01/rdf-schema#Resource>                       |
| <http://stackoverflow.com/q/21223545/1281433/space.owl#ApolloMission> |
| _:b1                                                                  |
-------------------------------------------------------------------------
于 2014-01-19T23:54:40.577 回答