OWL中奇怪的查询行为！ [英] Strange query behaviour in OWL!

问题描述

在OWL中，此查询工作正常

"person and hasChild min 3"

它工作正常，它给了我所有有3个以上孩子的人

但是这个不起作用

"person and hasChild max 3"

它应该给我所有少于3个孩子的人，但是它不起作用

有人对此有想法吗?

为什么最小"有效，而最大"却没有任何结果呢?

谢谢

解决方案

第二个查询不起作用"的原因是开放世界假设，并且可能还有(缺少)唯一名称假设.

您说:

John lives in Paris.
Mary lives in Paris.

OWL推理机以下列方式回答以下问题.

Who lives in Paris?  John, Mary
Does at least one thing live in Paris?  YES
Do at least two things live in Paris?  Maybe
Is Paris a person?  Maybe
Is John and Mary the same thing?  Maybe
Is Paris and Mary the same thing?  Maybe
Does at most one thing live in Paris?  Maybe

每当OWL推理机返回也许时，用户界面(例如Protege)往往什么也不显示.

为了获得您可能想要的答案，您需要向知识库中添加更多信息，例如

Mary is not John.
Everybody who lives in Paris is either John or Mary.

希望这会有所帮助.考虑到您最近对Stack Overflow提出的问题所获得的意见很少，所以暂时最好在Protege邮件列表中提出这些问题.甚至更好的是，查看邮件列表档案.每周至少有一次与开放世界假设相关的问题出现.

In OWL this query works fine

"person and hasChild min 3"

it works fine and it gives me all persons who have more than 3 children

but this one does not work

"person and hasChild max 3"

it should give me all persons who have less than 3 children however it does not work

does any one have an idea about this??

why "min" works while "max" does not give any results!??

Thanks

解决方案

The reason why the 2nd query "does not work" is Open World Assumption, and possibly also (the lack of) Unique Name Assumption.

Say you state:

John lives in Paris.
Mary lives in Paris.

The following questions are answered in the following way by an OWL reasoner.

Who lives in Paris?  John, Mary
Does at least one thing live in Paris?  YES
Do at least two things live in Paris?  Maybe
Is Paris a person?  Maybe
Is John and Mary the same thing?  Maybe
Is Paris and Mary the same thing?  Maybe
Does at most one thing live in Paris?  Maybe

Whenever the OWL reasoner comes back with a Maybe, the user interface (such as Protege) tends to show nothing.

In order to get the answers that you probably want, you need to add a lot more information to the knowledge base, e.g.

Mary is not John.
Everybody who lives in Paris is either John or Mary.

Hope this helps. Looking at how few views your recent questions have received on Stack Overflow, I'd say it's better to ask these questions on the Protege mailing list for the time being. Or even better, look at the mailing list archives. The Open World Assumption related questions come up at least once a week there.

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