- From: Yoandy Rodriguez <yrodriguezma@uci.cu>
- Date: Sat, 05 Mar 2011 19:05:43 -0500
- To: Michael Schneider <schneid@fzi.de>
- Cc: "public-owl-dev@w3.org" <public-owl-dev@w3.org>
Hello Michael, First, excuse my poor explanations of the problem, being only a test I have no formal or any description whatsoever. El sáb, 05-03-2011 a las 22:24 +0000, Michael Schneider escribió: > Hi Yoandy, concerning the second question, I still need to make sure whether I correctly understand you: > > >-----Original Message----- > >From: Yoandy Rodriguez [mailto:yrodriguezma@uci.cu] > >Sent: Friday, March 04, 2011 8:45 PM > >To: Michael Schneider > >Cc: public-owl-dev@w3.org > >Subject: RE: beginer question about inferencing > > > >El vie, 04-03-2011 a las 12:17 +0000, Michael Schneider escribió: > >> Hi Yoandy! > >> > >> Not an answer, but I need to ask for clarification. See below: > > [...] > > >> >also > >> >"if user have read access to a file then reading the file is allowed > >> >else it is forbidden" > >> > >> Do you mean: > >> > >> [1] "if there /exists/ at least one user ?u > >> who has read access to the specific file ?f, > >> then ?f is generally readable ("readable(?f)")" > >> > >> ? Or do you mean: > >> > >> [2] "if the /specific/ user ?u has read access > >> to the specific file ?f, then ?u is allowed > >> to read ?f ("allowedToRead(?u,?f)") > >> > >> ? In the case of [1], reading file ?f would then be forbidden > >("forbidden(?f)"), if there is no such user having read access to it. In > >case [2], if the /negation/ of the assertion "hasReadAccess(?u,?f)" > >holds, then the assertion "forbidden(?u,?f)" is entailed. Which one do > >you want to express (or maybe a third scenario)? > > [...] > > >Hello Michael, > > [...] > > >In the second expression I want to, if a given user ?user has a > >permission ?perm who matches any of ?file permissions, then state that > >the ?user can access the ?file, else state that he can't. > > So, is it the following scenario? > > * There are several individual users; > * there are several individual files; > * there is a fixed collection of file permissions (e.g. "read", "write", "delete", etc.); > * every file provides a certain sub set of file permissions; > * every user owns a certain sub set of file permissions, where, if he owns a permission ?p, he is then allowed to access /any/ file that provides ?p. > > The last point above is the most important one for me to understand the scenario. > > To give an example with user Alice and files dailymirror.pdf, phdthesis.tex, and topsecret.pdf: > > Alice --ownsPermissions--> { read, write } > > dailymirror.pdf --providesPermissions--> { read, delete } > phdthesis.tex --providesPermissions--> { write, read } > topsecret.doc --providesPermissions--> { delete } > > So, since Alice has generic "read" permission, she may access dailymirror.pdf and phdthesis.tex, which both provide "read" permission. In addition, since Alice also owns "write" permission, there is a second option for her to access phdthesis.tex, which still wants to be written. However, since topsecret.doc only provides "delete" permission and Alice does not own the "delete" permission, she is /not/ allowed to access topsecret.doc. > > Is this what you mean? This is exactly what I want, a way to classify an action depending on the intersection of user and file permissions. > > Cheers, > Michael > > -- > Dipl.-Inform. Michael Schneider > Research Scientist, Information Process Engineering (IPE) > Tel : +49-721-9654-726 > Fax : +49-721-9654-727 > Email: michael.schneider@fzi.de > WWW : http://www.fzi.de/michael.schneider > ============================================================================== > FZI Forschungszentrum Informatik an der Universität Karlsruhe > Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe > Tel.: +49-721-9654-0, Fax: +49-721-9654-959 > Stiftung des bürgerlichen Rechts > Stiftung Az: 14-0563.1 Regierungspräsidium Karlsruhe > Vorstand: Dipl. Wi.-Ing. Michael Flor, Prof. Dr. rer. nat. Ralf Reussner, > Prof. Dr. rer. nat. Dr. h.c. Wolffried Stucky, Prof. Dr. rer. nat. Rudi Studer > Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus > ============================================================================== >
Received on Sunday, 6 March 2011 00:06:33 UTC