Semantic Metadata to Support Device Interaction in Smart Environments
IOTDB - Semantic Metadata for the Internet of Things
29
IOTDB.org • Semantic Metadata for the Internet of Things Tuesday, 13 May, 14
-
Upload
david-janes -
Category
Internet
-
view
746 -
download
1
description
What is it? You have a simple data record { "on": true, "temperature": 250 } but without metadata there's no easy way to know what this data really is. This short presentation shows how JSON-LD can be used to describe this data, the IOTDB vocabulary for the Internet of Things (https://iotdb.org/pub/), and how the IOTDB software can quickly and easily create "Models" of your data.
Transcript of IOTDB - Semantic Metadata for the Internet of Things
IOTDB.org•
Semantic Metadata for the Internet of Things
Tuesday, 13 May, 14
Semantic Metadata
Tuesday, 13 May, 14
What is it?
{ "on" : true, "temperature" : 225}
Tuesday, 13 May, 14
Primary issues
• What does each field mean?
• What does this message represent?
Tuesday, 13 May, 14
Secondary issues
• Where is it?
• Who can access it?
• Not addressed in this presentation!
Tuesday, 13 May, 14
What does each field mean?
Tuesday, 13 May, 14
Control or Measurement?
• Does on mean:
• Turn it on? or
• Is it on?
• Does temperature mean:
• Set the temperature? or
• What is the temperature?
Tuesday, 13 May, 14
Units
• What does temperature refer to?
• degrees Celsius, Fahrenheit … or Kelvin?
Tuesday, 13 May, 14
And also...
• Is it measuring a specific substance, say O2 or CO concentration?
• we don’t want to mix these up!
• Axis (X / Y / Z)
• Related attributes, say the temperature you are setting vs. the temperature it is
Tuesday, 13 May, 14
What does a message represent?
Tuesday, 13 May, 14
What are we talking about … or with?
• An oven?
• A toaster?
• A sensor in the Large Hadron Collider?
• This is a hard problem
Tuesday, 13 May, 14
Classes?
• No!
• There is no neat hierarchy of Things
• Things can fall into many messy categories
Tuesday, 13 May, 14
Facets
• our solution is “Facets”
• a Thing may have many Facets, e.g.
• appliance, toaster, oven, sensor, a Wikipedia page…
Tuesday, 13 May, 14
@id
• A constant unique identifier for this Thing
• a IRI!
• It does not “evolve” as new readings are made
Tuesday, 13 May, 14
Placement
• Where is it?
• Address
• Lat / Lon
• Building, Floor, Room
• Person? Animal?
Tuesday, 13 May, 14
How to do it
Tuesday, 13 May, 14
Linked Data
• The core of the Semantic Web
• Describe data using triples:
• two objects and their relationship
• Use IRIs to represent all those things
• IRIs go to web pages that “make sense”
Tuesday, 13 May, 14
JSON-LD
• describe Linked Data using JSON
• easy-to-use (sorta)
• plenty o’ software and tools
Tuesday, 13 May, 14
IOTDB Models
• Write in Javascript
• easy to test, easy to understand
• Compiles to JSON-LD
•npm install iotdb
Tuesday, 13 May, 14
Write IOTDB Model…
iotdb.make_model('oven') .attribute( iotdb.control_boolean(":on") ) .attribute( iotdb.control_number(":temperature") .unit(":temperature.si.celsius") )
Tuesday, 13 May, 14
…Get JSON-LD…{ "@id": "#on", "@type": "iot:attribute", "iot:purpose": [ "iot-attribute:on", "iot-attribute:control" ], "iot-js:type": "iot-js:boolean"}…
Tuesday, 13 May, 14
Putting it all together
Tuesday, 13 May, 14
Data
{ "@context": "./meta-iri.jsonld", "on": true, "temperature": 225}
Note: @context is just one way of doing this!
Tuesday, 13 May, 14
Metadata…{ "@id": "#on", "@type": "iot:attribute", "iot:purpose": [ "iot-attribute:on", "iot-attribute:control" ], "iot-js:type": "iot-js:boolean"}…
Tuesday, 13 May, 14
N.B.
• The data does not have to be JSON!
• You don’t need to have IOTDB!
• You don’t need to use IOTDB IRIs (but you should)
• https://iotdb.org/pub/
Tuesday, 13 May, 14
Take aways
• describe the IoT using Linked Data
• Linked Data is IRIs
• IRIs for the IoT are defined by IOTDB
• but unlimited extensibility!
Tuesday, 13 May, 14
#iotdb
Tuesday, 13 May, 14
