1. An ontology-integration-position specifying apparatus comprising: a class storage unit that stores class mapping information in which a class included in an integration-source ontology and a class included in an integration-destination ontology are associated with each other, at a time of integrating hierarchical ontologies in which an attribute held by a superclass is inherited by a subclass and an inheritance relation can be specified, the integrating being performed according to the inheritance relation; an attribute memory that stores attribute mapping information in which a superclass of an associated class, which is a class in the integration-source ontology and associated in the class mapping information, an attribute held by the superclass of the associated class, and an integration destination attribute which is an attribute of a class in the integration-destination ontology and corresponding to the associated class are associated with each other; a class specifying unit that specifies an integration target class, which is an object to be associated with a class included in the integration-destination ontology, from classes other than the associated class and included in the integration-source ontology; an attribute-mapping-information acquiring unit that acquires attribute mapping information of an attribute which is held by a superclass of the integration target class and which is associated with the integration destination attribute in the integration-destination ontology, from the stored attribute mapping information; an associated class specifying unit that specifies an associated class having a shortest distance from the integration target class via a common superclass with the integration target class, among the associated classes included in the class mapping information; an integration-destination-associated-class specifying unit that specifies an integration-destination-associated class included in the integration-destination ontology and associated with the associated class specified from the class mapping information; and a position specifying unit that follows the inheritance relation as a route from the integration-destination-associated class specified, and specifies a class in the integration-destination ontology having the integration destination attribute corresponding to the attribute mapping information acquired by the attribute-mapping-information acquiring unit as a position where the class associated with the integration target class is present.
2. The apparatus according to claim 1 , further comprising: a class registering unit that registers the class present at the position specified by the position specifying unit and the integration target class in association with each other in the class mapping information; and an attribute registering unit that registers an attribute of the class present at the position specified by the position specifying unit, when the attribute has not been associated in the attribute mapping information stored, and an attribute of the integration target class, which is not included in the attribute mapping information acquired by the attribute-mapping-information acquiring unit, in association with each other in the attribute mapping information in the attribute storage unit.