WD-Ontology
richard at newb6.u-strasbg.fr
richard at newb6.u-strasbg.fr
Mon Feb 26 03:18:49 PST 2007
Hello,
Being the one in charge of the technical part of this ontology and its
uses, I thank you for your feedback.
>
> Is this not where relations come into play: you could define relations such
> as 'like a' and 'not quite a' and then, depending on what you want to do,
> manipulate the objects and relations in your code.
>
What your suggest is possible in general, and it may look the perfect
solution. Yet using relations like 'not quite a' is not really a viable
option for our work since it's impossible to associate clearly defined
semantics to such relations. And if we don't have clearly defined
semantics, we
can't trust the inferred results of a computer-based reasoning which is
a problem since our goal is to make the computer work in place of the
human.
One could argue that defined ontologies are not the only way of
proceeding but we chose them after considering taking into
consideration the existing reasoning tools and the fact that I am
myself not a complete novice when it comes to such structures.
Basically you can compare our implementation choices to the following
deal: accept one strong limitation (a defined ontology, thus with
non-fuzzy semantics) in exchange of
the use of very powerful inference possibilities and existing engines
(which allow us to save up much time and only consider to build
additional inference primitives only if we need to)
>
> And this is where the uniqueness of astronomy comes into play and we start
> to build intelligent *astronomy* applications rather than generic
> information handling apps.
>
I understand your concerns about the need to have
domain-oriented and not technology-oriented tool building. I also
realize that, being myself from the computer science field, I have to
somehow prove that I am not prone to code for the sake of coding and
without neither the application field nor the end-user in mind.
I am not sure to be able to convince anyone but here is my point of
view: my job is to help determining what ontologies can or cannot do
for astronomers. Moreover, I ultimately have to either deliver some
efficient applications with real added value for the end-users or get
enough evidence to
conclude that what I have tried to do cannot be done, at least with
current tools and knowledge.
Basically, what I am trying to do with all the astronomers i
collaborate with is to build efficient applications. We cannot just
build generic applications because it just wouldn't work. The
applications we work on are made for astronomers with the help of
astronomers, my job being to provide technical support like checking if
a proposition is technically doable, formalizing knowledge to build the
ontology accordingly to our constraints and ultimately developing the
applications.
Cheers,
Alexandre
--
______
/ ~ /, Alexandre RICHARD mailto:richard at astro.u-strasbg.fr
/ ~~~~ // Observatoire de Strasbourg Phone +33 (0) 390 242 477
/______// 11, rue de l'universite Telefax +33 (0) 390 242 417
(______(/ F-67000 Strasbourg France
Quoting Tony Linde <Tony.Linde at leicester.ac.uk>:
>> ordinarily one would include them. For instance, what if it
>> is like a
>> cataclysmicVariable but not quite a LateType star.
>
> Is this not where relations come into play: you could define relations such
> as 'like a' and 'not quite a' and then, depending on what you want to do,
> manipulate the objects and relations in your code.
>
>> whether or not to use strictly observational qualities or interpreted
>> qualities. As in, what if it erupts and has emissions like a
>
> And this is where the uniqueness of astronomy comes into play and we start
> to build intelligent *astronomy* applications rather than generic
> information handling apps.
>
> T.
>
>> -----Original Message-----
>> From: owner-semantics at eso.org
>> [mailto:owner-semantics at eso.org] On Behalf Of Ed Shaya
>> Sent: 21 February 2007 20:15
>> To: Andrea Preite Martinez
>> Cc: semantics at ivoa.net
>> Subject: Re: WD-Ontology
>>
>>
>>
>> Andrea Preite Martinez wrote:
>> > A Working Draft on
>> >
>> > Ontology of Astronomical Object Types, version 1.0
>> >
>> > has been uploaded in the Document section of IVOA
>> > http://ivoa.net/Documents/latest/AstrObjectOntology.html
>> >
>> > and in the Semantics WG twiki page
>> > http://www.ivoa.net/twiki/bin/view/IVOA/IvoaSemantics .
>> >
>> > In this page you can also find the ontology file (.owl) that can be
>> > explored/edited with the protégé browser/editor
>> > http://protege.stanford.edu/overview/protege-owl.html .
>> >
>> > The document and the Ontology are open to discussion and
>> contributions.
>> >
>> > Note that the ontology is made of "defined" concepts, and
>> only a fraction
>> > of them has been defined, for the moment only in terms of
>> components and/or
>> > morphology and/or processes.
>> > Indeed, there are still 87 astronomical concepts that are
>> missing an
>> > NS-condition (Necessary&Sufficient)
>> >
>> > I then ask for the contribution of the members of the WG and of the
>> > scientific
>> > community to help finding the necessary and/or sufficient
>> conditions to
>> > define the concepts.
>> > What is needed is a complete but concise description in
>> plain text of
>> > the concepts in terms of components/ morphology / physical
>> processes /
>> > observational properties and/or ...
>> >
>> > An example:
>> > CataclysmicVariable: close binary, components WD/subGiant
>> and LateType
>> > Star,
>> > variability due to thermonuclear processes...
>> >
>> > The concepts without NS-conditions (but sometimes already
>> with N or S
>> > conditions) are the following:
>> There are dangers in defining the necessary and sufficient
>> conditions,
>> particularly if one requires too many necessaries. You can
>> end up with
>> things that are not in any class although they are so close
>> to one that
>> ordinarily one would include them. For instance, what if it
>> is like a
>> cataclysmicVariable but not quite a LateType star. One also run into
>> whether or not to use strictly observational qualities or interpreted
>> qualities. As in, what if it erupts and has emissions like a
>> cataclysmic variable but it is too far away to discern the individual
>> components? Can you still call it a CV?
>>
>> On the other hand, if we don't make clear and distinct boundaries you
>> are left with a system that is too fuzzy to do any good.
>>
>> Having noted these difficulties, in the grand tradition of
>> semantics, we
>> simply push forward and appreciate that we can always pull
>> back on some
>> of these NS qualities or define both strict and loose
>> versions of each
>> class, as in StandardCalaclysmicVariable/TentativeCataclysmicVariable.
>> >
>> > AssociationOfStars - alias (equivalent class) StellarAssociation
>> Loose concentration of young stars (how loose? 1-100 per
>> cubic pc?), but
>> may contain 1 or more StellarClusters within it.
>> subclasses -
>> OB-Association - association with many O and B stars
>> (massive stars)
>> R-Association - contains medium mass stars with
>> reflection nebulae
>> T-Association - contains only low mass stars including
>> some T-Tauri stars
>>
>> > ClusterOfGalaxies - alias GalaxyCluster
>> Observationally - a region with a concentration of galaxies several
>> times the neighboring background density with similar galaxy
>> redshifts.
>> Theoretically - a collapsed and virialized system of galaxies
>> subclasses
>> AbellCluster - there are two definitions here
>> a) A cluster in the Abell Catalog
>> b) A cluster with the criteria given by Abell
>> for his catalog
>> Perhaps a) should be called an AbellCatalogCluster
>>
>> > SuperClusterOfGalaxies
>> A 3-d region of contiguous overdensity on Mpc scales.
>> Usually these
>> contain several clusters, but this should not be the
>> definition becuase
>> a) the Local Supercluster contains only 1 cluster b) if one found a
>> large contiguous overdensity without a cluster you probably
>> would still
>> want to classify it as a supercluster.
>>
>> > ClusterOfStars - alias StarCluster.
>> Observational - A tight system of stars with less than 10^9 stars.
>> Theoretical - A system of stars formed out of a single cloud
>> of gas and
>> with less mass than a galaxy (that is, .
>>
>> > GlobularCluster -
>> A roughly spherical ClusterOfStars with 10^4 - 10^9 stars and with an
>> orbit that takes it out of the plane of its parent galaxy.
>> [Normally the definition would include the idea that it is
>> composed of
>> old stars, but blue globular clusters in N1375 and other
>> galaxies show
>> that there are exceptions. Also, when globular clusters were
>> young they
>> had young stars and they were still globular clusters.]
>>
>> > OpenCluster - alias GalacticCluster
>> ClusterOfStars with young stars and with center of mass orbit
>> that stays
>> in the plane.
>>
>> > GalaxiesGroup
>> This should be GalaxyGroup - alias GroupOfGalaxies.
>> A system with on the order of 10 galaxies separated by 10-100 galaxy
>> diameters [Hopkins, J. 1976 Glossary of Astronomy and Astrophysics]
>>
>> I stop here to rest and wait for comments.
>> Ed
>> > Galaxy
>> > ActiveGalaxyNucleus
>> > Blazar
>> > BLLacObject
>> > OpticallyViolentlyVariableObject
>> > LINERTypeActiveGalaxyNucleus
>> > SeyfertGalaxy
>> > Seyfert1Galaxy
>> > Seyfert2Galaxy
>> > BlueCompactGalaxy
>> > EmissionLineGalaxy
>> > HighRedshiftGalaxy
>> > HIIGalaxy
>> > LowSurfaceBrightnessGalaxy
>> > QuasiStellarObject
>> > StarburstGalaxy
>> > SpectroscopicBinary
>> > XRayBinary
>> > InterStellarMedium
>> > EmissionNebula
>> > HIRegion
>> > HIRegionCold
>> > HIRegionWarm
>> > MolecularCloud
>> > BokGlobule
>> > DarkCloud
>> > ReflexionNebula
>> > StellarObject
>> > BrownDwarf
>> > Star
>> > PostAsymptoticGiantBranchStar
>> > RedGiant
>> > AsymptoticGiantBranchStar
>> > CarbonStar
>> > OHIREnvelopeTypeStar
>> > STypeStar
>> > RVTauri
>> > PeculiarStar
>> > CHEnvelopeTypeStar
>> > BeStar
>> > WolfRayetStar
>> > HorizontalBranchStar
>> > StellarRemnant
>> > NeutronStar
>> > Pulsar
>> > AccretionPoweredPulsar
>> > Magnetar
>> > RotationPoweredPulsar
>> > StellarBlackHole
>> > WhiteDwarf
>> > YoungStellarObject
>> > PreMainSequenceStar
>> > HerbigHaro
>> > TTauri
>> > ClassicalTTauri
>> > WeakLineTTauri
>> > ProtoStar
>> > SubStellarObject
>> > BrownDwarf
>> > NonStellarBody
>> > Asteroid
>> > Comet
>> > Planet
>> > CataclysmicVariable
>> > DQHerCataclysmicVariable
>> > DwarfNova
>> > Nova
>> > NovaLikeObject
>> > RapidIrregularVariableStar
>> > IrregularVariableStar
>> > RapidIrregularVariableStar
>> > BetaCepheid
>> > LTypeIrregularStar
>> > MiraCeti
>> > SemiRegularPulsatingStar
>> > RRLyrae
>> > WVir
>> > BYDraconis
>> > EllipsoidalVariableStar
>> > SymbioticStar
>> >
>> >
>> > P.S.:
>> > I think we can envisage a half-session in the spring IVOA
>> meeting in
>> > Beijin dedicated to the ontology and its applications.
>> >
>> > Andrea
>> >
>> >
>> ==============================================================
>> =====================
>> >
>> > Andrea Preite Martinez
>> > andrea.preitemartinez at iasf-roma.inaf.it
>> > IASF Tel.IASF:+39.06.4993.4641
>> > Via del Fosso del Cavaliere 100 Tel.CDS :+33.3.90242452
>> > I-00133 Roma Cell.1 :+39.320.43.15.383
>> > Cell.2 :+39.
>> >
>> ==============================================================
>> =====================
>> >
>> >
>> >
>> >
>>
>
>
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