- From: Rob Atkinson <rob@metalinkage.com.au>
- Date: Fri, 01 Jul 2016 07:35:35 +0000
- To: Simon.Cox@csiro.au, rob@metalinkage.com.au, kerry.taylor@anu.edu.au, public-sdw-wg@w3.org
- Message-ID: <CACfF9LxmsDFepCv7-NqUx_z1M=3y3EzBY_d28iNO1EF4DkKNqQ@mail.gmail.com>
Thanks Simon It sounds like what you are working on is much closer to what I was looking for :-) I dont think i was proposing a single core really - its just that by focusing on the one module of the proposed modularisation it may have sounded like it. AFAICT the other two modules - sensors, deployments still exist as viewpoints with relatively neat boundaries. I would be happier still if the bottom tier was itself split into modules mirroring the owl-y tier above - representing a true "veritical" modularity pattern - and if necessary the links between then contained as statements in additional artefacts. If this is not practicable there should be a justification possible in a visualisation of the offending inter-relationships. (Simplicity is not a smaller number of pieces, so much as an obvious relationship between the pieces and a small number of patterns. The patterns for module relationships I see are: 1) import and add elements (not sure we need this - but it may be the end Use Case pattern ) 2) import and add semantics (vertical modules) 3) import A,B to add A->B and B<-A relationships without compromising ability to import just A or just B (aid to horizontal modules) 4) import A,B to create reified alignments X->A, X->B, X.metadata* (alignment module) 5) import A,B,C... to create a single artefact point of entry for an application needing multiple modules (e.g. SSN in the layer diagram) These seem to follow our requirements breakdown - is there a existing characterisation of such patterns we could leverage? No one has thrown it out there during discussions - but it seems fairly obvious like Object Relational Mappings have well known patterns. Rob On Fri, 1 Jul 2016 at 16:10 <Simon.Cox@csiro.au> wrote: > Thanks Rob. Insightful, and challenging, as usual. > > > > Jumping to the bottom, I think you are suggesting that the Observation > viewpoint should be the core. > > I’m not sure this works, as there are at least three key viewpoints, which > emphasize different primary concerns > > - Provider/sensor – sensor, platform, sensor network, observed > property > > - Provider/sampling – site, station, specimen, feature of > interest > > - Consumer – observed property, result, feature of interest > > The first two are not addressed by the O&M Observation schema. > > These three cores would correspond approximately to one axis of Jano’s > vertical/horizontal modularization idea [1]. > > > > As you are probably aware, I created om-lite and sam-lite [2] as a > strawmen for two cores, with the expectation that there would be a third > core, dealing with the sensor side. > > (Sensors are deliberately and explicitly delegated elsewhere in both O&M > and om-lite - they both only have a stub/abstract class for the range of > the procedure property.) > > The primary goal in om-lite was a more idiomatic OWL version of O&M than > following the ISO 19105-2 rules produce [3], also with fewer dependencies > and thus fewer semantic commitments. (It is a lot more than “pure RDFS”.) > > > > Subsequent discussion on the SDWWG lists suggests that there may still be > too much semantics in om-lite/sam-lite for a core – > > - there are explicit domains and ranges in some places, and lots > of local (guarded) restrictions, and some properties are declared functional > > - while these ontologies are mostly self-contained, sam-lite has > a dependency on PROV > > - om-lite includes a taxonomy of specialized observation > classes, and sam-lite of specialized sampling feature classes. > > > > schema.org is being suggested as a paradigm for the core, i.e. a flat > list of classes and properties in a single namespace with few relationships. > > Working on this assumption, then if there is a single core, then it should > do little more than enumerate the key ½ dozen classes, and a comparable > number of properties corresponding with a bland set of interrelationships, > with no formal domain/range or restrictions – essentially just “tags”. > > In the last day I’ve been working with Armin on a proposal in that > direction [4]. > > This takes Jano’s proposal [1] and adds > > - SamplingFeature > > - separate classes for Procedures and Devices > > - Actuator. > > Personally I’m not convinced that the latter two belong in the core – I > think I would move those considerations up into the next layer, but they > are there for the moment. > > This would be the base of a stack something like this (would be better > arranged in concentric circles, but I don’t have a tool to do that): > > > > > > Note that Armin and I have been struggling to get WebProtege to behave, > and are not convinced it is the long term solution L > > > > Finally, a request to everyone – **please include links to the things you > are discussing or complaining about** . > > It may take a little more of your time when constructing your message, but > it will save a lot more for everyone else. > > And in particular, it helps everyone else come along with you if they can > just click and see the actual artefact under discussion. > > > > Simon > > > > [1] https://www.w3.org/2015/spatial/wiki/SSN_core_modules > > [2] http://def.seegrid.csiro.au/ontology/om/om-lite > > http://def.seegrid.csiro.au/ontology/om/sam-lite > > [3] > http://www.semantic-web-journal.net/content/ontology-observations-and-sampling-features-alignments-existing-models-0 > > http://ceur-ws.org/Vol-1063/paper1.pdf > > [4] > http://webprotege.stanford.edu/#Edit:projectId=da9180fc-add3-4b6a-96d0-bf66c52744b7 > > > > > > *From:* Rob Atkinson [mailto:rob@metalinkage.com.au] > *Sent:* Thursday, 30 June 2016 9:35 PM > *To:* Kerry Taylor <kerry.taylor@anu.edu.au>; Cox, Simon (L&W, Clayton) > <Simon.Cox@csiro.au>; public-sdw-wg@w3.org > *Subject:* Re: ssn: lost something? > > > > OK - throwing myself as a sacrifice into the teeth of the storm here ... > > > > I've spent a bit of time looking at the SSN ontology and seeing where the > "natural joints" appear to be and looked at the whiteboard sketch around > proposed modularisation.... > > > > If I then think about the Use Case of a set of OGC SensorWeb services > deployed, and using SSN to provide a metadata layer that would allow > reasoning about these and how they relate to each other... > > > > (at this point - if SSN is purely intended as a language for encoding > results of sensing - not for describing sensing independent of the encoding > of the results - then read no further and we'll go our separate ways > without further pain...) > > > > I get, and endorse the separation of RealWorld (Stimulus Sensor > Observation seems an ugly name - but the packaging of concerns seems OK, > Device and Deployment.... ) > > > > more on the RealWorld module later... > > > > where things go awry for me is the imports.... > > > > O&M is not going to import this - but an O&M profile that wants to define > the sensor process in a specfic level of detail may import parts of SSN. > > The containing rings are a problem though - you can only import a specific > named, described, versioned artefact - not a vagure grouping - you'd need > to name a package even if all it does is contain transitive imports. And > the user will need it described to know how to use it this way. > > > > And this leads me to the questions I expect will bring a rain of frogs > upon my head.. > > > > I think we need to have a much clearer picture of how the modules would > provide specific functional outcomes. I'm sure others have thought in more > detail how to do this - and the suggestions below come from the perspective > of not being able to see into that thinking well enough but wanting to > support some fairly obvious use cases around deploying existing OGC > standards with a much improved ability to share details about the sensing > process. > > > > IMHO there are several touch points and requirements w.r.t. the O&M space: > > 1) there is a pre-existing scope of O&M implemented in existing services, > and if we want to talk about this body of information with a more powerful > language (SSN) then we need a first-class mapping to O&M concepts > > 2) There is not yet AFAICT a canonical O&M ontology formalised in OWL - > however there are candidates (?) IMHO The ISO 19150 approach to encoding > O&M appears unworkable however. The "modular" model - the vertical modules > - RDFS, OWL-DL, SKOS etc views are necessary. > > 3) SSN has some extended semantics but does not at first glance appear to > be fundamentally inconsistent with O&M > > 4) Users will hate us if there are multiple virtually indistinguishable > approaches > > 5) The RealWorld maps properties of the Feature of Inerest to the sensing > process... this seems to be where SamplingFeature comes in. > > > > I would like to plead for an attempt to break the RealWorld module into > several distinct modules with these characteristics: > > 1) O&M -lite - a pure RDFS vocabulary of the definitions used in O&M, as a > canonical O&M ontology > > 2) O&M-sensor (imports O&M lite and any other SSN modules necessary) - > defines sensor related extensions that allow an O&M instance to be attached > to SSN details. (this may be quite trivial and only contain the links > between observation and Sensing, Sensor etc - perhaps characterised as > subProperties of om:observationProcess? > > 3) An alignment module if required mapping SSN1 terms to the new > equivalents in appropriate namespaces, and defining the necessary imports) > > 3) SSN-ObservedFeature (imports O&M lite and a general spatial ontology > defining a Feature) - that defines properties of a Feature, and > relationships between a Feature and a SamplingFeature, and the real world > phenomena being described > > > > Device and platform modules would provide for device specific details of > how the phenomenon is measured. Deployment would identify the > samplingFeature and FoInterest. SSN-ObservedFeature would provide the link > between the FeatureOfInterest and how its properties are measured via a > SamplingFeature. > > > > Maybe we first need to explore if we can identify a canonical O&M > vocabulary we can re-use - and if there are fundamental mismatches with SSN > semantics? If this has been discussed and documented, just add these > discussions as links in the modularity discussions I've been pointed to and > I'll try to understand them. I'm assuming the lack of such links means this > is just the elephant in the room - and step in to wrestle it like a fool. > > > > > > Rob > > > > u, 30 Jun 2016 at 11:22 Kerry Taylor <kerry.taylor@anu.edu.au> wrote: > > No – I was referring to the version of SSN as published with the FPWD, as > I said: https://www.w3.org/ns/ssn/ . It also corresponds to the ontology > documentation in the FPWD. Those things appear to have been dropped > accidently. > > > > *From:* Simon.Cox@csiro.au [mailto:Simon.Cox@csiro.au] > *Sent:* Wednesday, 29 June 2016 6:03 PM > *To:* Kerry Taylor <kerry.taylor@anu.edu.au>; public-sdw-wg@w3.org > *Subject:* RE: ssn: lost something? > > > > Are you looking at SANDA in WebProtege? > > That is very incomplete yet. > > > > I still see all the restrictions in the version of SSN here > http://purl.oclc.org/NET/ssnx/ssn > > > > Simon > > > > *From:* Kerry Taylor [mailto:kerry.taylor@anu.edu.au > <kerry.taylor@anu.edu.au>] > *Sent:* Tuesday, 28 June 2016 6:16 PM > *To:* public-sdw-wg@w3.org > *Subject:* ssn: lost something? > > > > Joel and I were looking at ssn today in the context of IoT and we noticed > that “ssn:Observation” has lost its restrictions for properties > “ssn:observationResultTime”, “ssn:qualityOfObservation” and > “ssn:observationSamplingTime” somewhere in the translation to the FPWD > form. > > Can anyone explain? Have any others gone missing? Is a more thorough check > warranted? > > > > --Kerry > >
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Received on Friday, 1 July 2016 07:36:29 UTC