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Re: [TF-LD] Draft charter for Linked Data and Semantic Processing Task Force

From: Dave Raggett <dsr@w3.org>
Date: Wed, 1 Mar 2017 16:48:17 +0000
Message-Id: <A3976467-2C1C-4BAA-ABE8-FE256C373F89@w3.org>
Cc: "Kis, Zoltan" <zoltan.kis@intel.com>, public WoT IG <public-wot-ig@w3.org>
To: "Anicic, Darko" <darko.anicic@siemens.com>

> On 1 Mar 2017, at 15:26, Anicic, Darko <darko.anicic@siemens.com> wrote:
> Von: Dave Raggett [mailto:dsr@w3.org <mailto:dsr@w3.org>]  
> I envisaged a scenario where a service designer (a human) sits at a workstation and comes up with an application that can perform a service like controlling the home environment, adapting to what devices are available in each home. This requires the device descriptions to declare what semantic modules (oneM2M sense) they support. The interfaces exposed by different air conditioners, for example, might differ, but the application would know how to adapt to each, without needing to know in advance the details of each device.
> This is more tractable than what you describe as it just requires a way to describe the semantic modules that devices may support and does not require a standard for describing event-condition-action rules or other ways to describe behaviours.
> Your example is also interesting. An example with ECA rules was picked by chance. Recipe is based on ingredients and interactions between them. Ingredients should be TD templates or perhaps abstract TDs (suggested by Kajimoto-san). These are similar to semantic modules you mentioned. We don’t need a standard to describe certain type of rules or behaviours. Instead we need just a format to specify a recipe with a semantic model behind. 

Then this sounds like something I already did last year for the oneM2M and OCF specifications using an import declaration in JSON that maps to the td:import predicate in the Linked Data for thing descriptions.  This is a purely syntactic approach to modularisation. 

We also need a semantic approach in which a thing, property, etc. uses rdf:type to assert that it supports the given semantic model. A rather basic example is where a property for a temperature reading asserts that it is a temperature measurement. The RDF class for this requires instances of the class to provide a numeric value, and a units of measure corresponding to a recognised temperature scale. In principle, the constraints could be inherited from a super class, but we need to be careful about how to handle exceptions (ostriches are birds, birds fly, but ostriches don’t).

Validation of such semantic constraints can be readily handled with shape rules. Ontologies cannot support validation on their own. I am happy to provide working examples and welcome suggestions for use case examples.

p.s. shape rules are a subset of cognitive rules, but that is a longer story and something for another time.

Best regards,

Dave Raggett <dsr@w3.org> http://www.w3.org/People/Raggett
W3C lead for the Web of things

Received on Wednesday, 1 March 2017 16:48:32 UTC

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