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Re: Modeling a specific construct - please help

From: Uli Sattler <sattler@cs.man.ac.uk>
Date: Mon, 14 Sep 2009 15:51:12 +0100
Cc: public-owl-dev@w3.org
Message-Id: <C7986F93-FD00-4501-8E0A-525F7C9B7E14@cs.man.ac.uk>
To: Milan Zdravkovic <milan.zdravkovic@gmail.com>

On 14 Sep 2009, at 14:28, Milan Zdravkovic wrote:

> OK, here is demo example at: http://www.masfak.ni.ac.rs/ontologies/2009/8/process_demo.owl
>

thanks, that helps

> What's bothering me is, without going deeper into semantics of used  
> terms:
>
> 1. Why RDQL "suceeds min 2 Activity" do not return Activity_3, and  
> "suceeds some Activity" does ?

because we don't know that Activity_3 (I think you mean Activity_C?)  
has at least 2 succeeds successor: it may be the case that Activity_A  
and Activity_B are identical...try adding a Different Individual to  
Activity_A, Activity_B, and then try again.

> 2. Why Activity_1 isConcurrentWith Activity_2 (and Activity_1  
> isConcurrentWith Activity_1, in this case) is not inferred ?

because you haven't said anything in your ontology that  would entail  
this. You have stated domain and range restrictions on your 3  
properties, and said that preceeds is the inverse of succeeds, but not  
more.

I guess you you meant to say that

the property *chain* (succeeds o preceeds) implies  isConcurrentWith

but you haven't stated this in the ontology,  and it also isn't quite  
the right thing to say, is it:

- it would only 'catch' 'sibling' relationships (in contrast to  
cousins, etc.), and

- it implies, e.g., that   Activity_B isConcurrentWith  Activity_B,  
and you don't want that.

> 3. Is there another way to axiomatize this relationship (although  
> semantics of used terms is not actually precise, you are right, Uli,  
> but I hope you get what I want to achieve) ?
>

have a look at

http://www.cs.manchester.ac.uk/~stevensr/menupages/fhkb.php

it should help clarify things

Cheers, Uli

> Thanks for your help,
> Milan
>
> 2009/9/11 Uli Sattler <sattler@cs.man.ac.uk>
>
> On 11 Sep 2009, at 15:21, Milan Zdravkovic wrote:
>
> Thanks Uli !
>
> 2009/9/11 Uli Sattler <sattler@cs.man.ac.uk>
> this is a difficult one:
>
> - I assume that Ab, B, and C are individuals, and that 'preceeds' is  
> 'directly preceeds' (otherwise, you should *not* conclude that A is  
> ConcurrentWith C.
>
>
> Yes, "preceeds" is not transitive property
>
> - you can introduce a transitive superproperty 'preceeds-trans' of  
> preceeds and find all instances of the class (e.g., via OWL API and  
> reasoner or via the DL query tab in Protege 4):
>
> (preceeds-trans value C) or (Inv(preceeds-trans) value C)
>
> if A is *not* in the answer to this query, then you can assume that  
> it is ConcurrentWith C.
>
>
> Thanks for the effort, but I would like to keep the ontology  
> meaningfull, that is to avoid using "supporting" concepts for  
> inference.
>
> I understand - but from  " A preceeds B and C preceeds B,", it does  
> not follow that "A isConcurrentWith C" -- unless you mean indeed  
> that 'preceeds' is 'directly-preceeds'....and then you do need some  
> transitive superproperty to talk about precedence in general?!
>
>
>
> Do you possibly know why "preceeds some (succeeds min 2  
> ProcessActivity)" is not working ?
>
> what do you mean by 'not working'? You need to give us more context  
> and more detail on what it is that isn't working.
>
> Cheers, Uli
>
>
> I am confused about this - existential restriction works ("preceeds  
> some (succeeds some ProcessActivity)") but cardinality - obviously  
> not ?!
>
> Cheers, Uli
>
>
>
> On 11 Sep 2009, at 12:27, Milan Zdravkovic wrote:
>
> I am a beginner in OWL, working on specific process ontology. I have  
> a problem in inferring the concurrency of process activities, for  
> example - on basis of asserted A preeceds B and C preceeds B, I need  
> to infer that: A isConcurrentWith C.
> I was trying with modeling domain of isConcurrentWith with  
> (Manchester syntax):
> preceeds some (suceeds min 2 ProcessActivity)
> , where preceeds properties are asserted and suceeds is inferred  
> inverse property, but without success.
>
> Could you please help me on this ?
>
>
>
>
>
>
>
> -- 
> Milan Zdravkovic,
> IT Business Development Consultant
> Inovation Center for Information Technologies (ICIT), Faculty of  
> Mechanical Engineering, University of Nis
>
> Phone: +381 64 1144797
> Email: milan.zdravkovic@gmail.com
> WWW: http://icit.masfak.ni.ac.yu/milan.zdravkovic
> LinkedIn: http://www.linkedin.com/in/milanzdravkovic
> Address: ul. Kovanlucka 58, 18000 Nis, Serbia
> ---------------------------------------------------------
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> National EURAXESS portal: Facilitating researchers mobility to and  
> from Republic of Serbia
>
>
>
Received on Monday, 14 September 2009 14:51:36 GMT

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