Meeting minutes
Logistics
kaz: agenda and logistics. Guests today: Linda and Scott
Minutes
<kaz> March 2
Kaz goes over previous minutes.
kaz: We need to talk about next charter as well.
… Still waiting for the slides of the last meeting's presentation.
RESOLUTION: minutes approved
Progress check
Kaz: we want to write a Note, possibly called Technology Landscape around Web-based Digital Twins for Smart Cities
Kaz shows the current template for the note
<kaz> GitHub area for the Note
kaz: we can update based on our discussions, such as today's, and liaisons.
… today's topic is collaboration with OGC
Collaboration with OGC (presentation)
Linda shows some slides
linda: OGC has several standards, for geospatial data formats, etc.
… With these standards we, e.g., us at Geonovum, can create interoperable digital twins.
… about soil, rainfall, traffic, etc.
… We are mostly making simulations.
… And testing them in so-called testbeds
… Companies get grants to do testing.
… (I'm skipping many slides with examples.)
… Here is one use case and I'll explain the standards involved.
<kaz> [Get backdrop of Almere]
linda: The use case is about heavy rainfall, that may flood streets.
… Start with an aerial photograph.
… Using OGC APIs we can get data, such as maps.
<kaz> [Search for cloudburst simulator]
linda: Then we search for a model that can do the calculations.
… OGC API Records is an OGC standard that we use for data sets (DCAT)
<kaz> [API Processes]
linda: Once found, we add interactions, with OGC API Processes
… The user gets back that a simulator is available and he has to fill in some fields.
… That informs the process of the needed data.
… Data comes back in a standard format.
<kaz> [Async]
linda: After the calculation, which can take some time, the user gets back the results.
… This is an example of the OGC standards that can be involved in a digital twin.
Scott: The context of the digital twin is always understandable and compatible.
… Including the digitial representations of sensors.
… We've been working with several standards bodies for that, including W3C.
… DCAT was already mentioned as an example.
kaz: Thanks for that presentation.
… You mentioned DCAT.
… How about Web of Things as another model for sensors and devices?
scott: Already some standards in OGC, such as SOSA/SSN joint with W3C.
… All those sensors, for use, need a time and space.
kaz: WoT in W3C is working on a data model,
… but it doesn't have concrete time and location.
linda: When I was in the Spatial Data WG, there were people looking into how the models correspond.
… About if they were at different levels and could be combined.
kaz: wondering about logic handling mechanism for orchestration of multiple entities, a possibility is State chart model as basis for synchronizing streams.
scott: There has been some work in API for connected services.
… We have to dig a bit to see what is present.
mjk: I think much is complementary.
… WoT doesn't define its own API.
… It is more like a semantically rich data model based on JSON-LD
… WoT is a fairly compact JSON-LD vocabulary.
… It connects to annotations from other standards.
… It doesn't try to replace other layers.
… It is for coupling.
… In the context of deployment, how do these pieces work together?
… WoT sort of fills in the cracks.
… We try to create a bigger, overall standard.
… In this group we look at how everything fits together
linda: Sounds like interesting work to write that Note that describes how everything fits
… OGC would be part of the description.
kaz: One point might be user credentials and authorization.
… Are there standards for that?
linda: Nothing specific to geospatial. We use general mechanisms
linda: There is still work on a new version of SOSA/SSN
mjk: Things interactive and asynchronously. In smart buildings, e.g., the sensor can be coupled to a location. In smart cities, it will be a different smart model.
… E.g., temperatutre of solar panel array.
… It is kind of ad hoc.
… We could start in our doc to give guidance.
… Examples and guidance, some constraints on annotations, on client access to semantics.
… Let's queue up a presentation on WoT.
… About Thing Descriptions, new sophisticated interactions.
kaz: We don't have anybody today, be we can do that next time.
… About buildings: There are probably many trials for smaller ontologies.
… Do you have ways to refer to such emerging ontologies?
… Maybe via DCAT or SOSA.
<kaz> Building Topology Ontology
linda: I think the OGC Building Blocks allow referring to ontologies.
scott: As long as the ontologies are registered.
… OGC standards are highly modularized.
… This is maturing now, not a lot that is already done.
kaz: We'd like JTC1, W3C ond OGC to collaborate.
… JTC4 has been created and the global situation is still kind of messy, but the mechanisms in JTC should be more clearly defined.
mjk: Having RDF ontologies and namespaces makes it easier, especially compared to when we only had APIs
linda: Is there already an ontology for properties such as temperature, weight, speed?
<kaz> QUDT Ontologies
mjk: QUDT is I think the best.
… Avoids problems such as Celsius vs Fahrenheit.
… What's missing is a good defintiion of what is a set point, rolling average, minimum and maximum.
… We are doing a bit of that, also for alarm point, but not yet high and low alarm points.
… That looks like another opportunity for a group to come together and define it.
… CDL (Control Description Language) has some math functions and logics for control flow.
… It comes with an RDF ontology..
… Building Ontology specs.
… Real estate core merged with Brics.
<kaz> RealEstateCore
mjk: We can maybe do a survey of what is available in the world of real estate,
… Also automotive and energy, solar energy.
… All those are candidates for integration.
… With AI and agents, you can then build a functional system.
… Digitial twins that combine what people are already doing.
… Another example is waste water: what are people doing there?
kaz: Your comment implies that our Note should have a section on ontologies.
mjk: Yes, it is not always obvious. I think we should go to that level of detail in the Note.
kaz: Any more discussion points for today?
… We can ask Torbjorn, etc. to talk about their work.
… And let's continue the survey and talk about use cases.
… I'll find the next date for the May meeting.
Linda: I'll send you my slides
<kaz> [adjourned]