Semantic Trajectory Episodes Ontology

3 November 2015

This version:
http://purl.org/net/step# (OWL/RDF)
Latest version:
http://purl.org/net/step# (OWL/RDF)
Authors:
Tales P. Nogueira (Laboratoire d'Informatique de Grenoble),
Hervé Martin (Laboratoire d'Informatique de Grenoble)

Valid XHTML + RDFa Creative Commons LicenseThis work is licensed under a Creative Commons Attribution License. This copyright applies to the Semantic Trajectory Episodes Ontology Specification and accompanying documentation in RDF. Regarding underlying technology, the Semantic Trajectory Episodes Ontology Specification uses W3C's RDF technology, an open Web standard that can be freely used by anyone.


Please cite the following paper if you use or refer to this ontology: T. P. Nogueira and H. Martin, "Querying Semantic Trajectory Episodes" in 4th ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems (MobiGIS'15), 2015.


Abstract

The Semantic Trajectory Episodes (STEP) is a lightweight ontology for representing semantic trajectories and contextual elements in terms of features of interests and episodes.

Status of This Document

The template of this specification is derived from the FOAF Vocabulary Specification, which was created by Dan Brickley and Libby Miller, and the Ordered List Ontology, which was created by Samer A. Abdallah and Bob Ferris. It was modified by Tales P. Nogueira. Furthermore, a modified and extended version of Danbri's SpecGen version was used to generate most of the RDFa statements for this specification (see here for SpecGen version 6 by Bob Ferris).

Semantic Trajectory Episodes Ontology at a glance

For detailed information, please refer to the paper.

An a-z index of Semantic Trajectory Episodes Ontology terms, by class (categories or types) and by property.

Classes: | Agent | ContextualElement | Episode | Extent | FeatureOfInterest | Fix | Geometry | Instant | KeyPoint | Point | QualitativeDescription | QuantitativeValue | RawTrajectory | SemanticDescription | SpatialExtent | SpatiotemporalExtent | TemporalEntity | TemporalExtent | Trajectory | Unit |

Properties: | asWKT | atTime | hasEndingPoint | hasEpisode | hasExtent | hasFeature | hasFix | hasLocation | hasPoint | hasRawTrajectory | hasSemanticDescription | hasStartingPoint | hasTrajectory | hasUnit | hasValue | relatesTo |

Semantic Trajectory Episodes Ontology cross-reference: Listing Semantic Trajectory Episodes Ontology Classes and Properties

The Semantic Trajectory Episodes Ontology introduces the following classes and properties. There is a link at the top of this document to the RDF/XML and RDF/N3 versions.

Classes: | Agent | ContextualElement | Episode | Extent | FeatureOfInterest | Fix | Geometry | Instant | KeyPoint | Point | QualitativeDescription | QuantitativeValue | RawTrajectory | SemanticDescription | SpatialExtent | SpatiotemporalExtent | TemporalEntity | TemporalExtent | Trajectory | Unit |

Properties: | asWKT | atTime | hasEndingPoint | hasEpisode | hasExtent | hasFeature | hasFix | hasLocation | hasPoint | hasRawTrajectory | hasSemanticDescription | hasStartingPoint | hasTrajectory | hasUnit | hasValue | relatesTo |

Classes and Properties (full detail)


Classes

Class: step:Agent

Agent - The agent is the moving object. It can be a person, an animal, a car, etc.
Status: unknown
Properties include: hasTrajectory
OWL Class

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Class: step:ContextualElement

Contextual Element - The contextual element can be anything related to the trajectory. It can be another agent, another trajectory, a geographic feature, etc.
Status: unknown
Used with: relatesTo
OWL Class

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Class: step:Episode

Episode - The episode is the smallest semantic unity for discretizing some aspect of a Feature of Interest.
Status: unknown
Properties include: hasSemanticDescription relatesTo hasExtent
Used with: hasEpisode
Restriction(s): The property step:hasSemanticDescription must be set http://purl.org/net/step#SemanticDescription time(s) and 1 time(s)
OWL Class

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Class: step:Extent

Extent - Extent is a superclass for all kinds of extents an Episode may have.
Status: unknown
Used with: hasExtent
Has sub class Spatiotemporal Extent Temporal Extent Spatial Extent step:SpatiotemporalExtent step:TemporalExtent step:SpatialExtent
OWL Class

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Class: step:FeatureOfInterest

Feature of Interest - The aspect of the trajectory or context that is being described. Example: speed, direction, etc.
Status: unknown
Properties include: hasEpisode
Used with: hasFeature
Restriction(s): The property step:hasEpisode must be set http://purl.org/net/step#Episode time(s) and 1 time(s)
OWL Class

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Class: step:Fix

Fix - A Fix is a spatial timestamped point.
Status: unknown
Used with: hasFix
OWL Class

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Class: sf:Geometry

Geometry - Geometry is the root class of the hierarchy. The instantiable subclasses of Geometry are restricted to 0, 1 and 2-dimensional geometric objects that exist in 2, 3 or 4-dimensional coordinate space (R2, R3 or R4). Geometry values in R2 have points with coordinate values for x and y. Geometry values in R3 have points with coordinate values for x, y and z or for x, y and m. Geometry values in R4 have points with coordinate values for x, y, z and m. The interpretation of the coordinates is subject to the coordinate reference systems associated to the point. All coordinates within a geometry object should be in the same coordinate reference systems. Each coordinate shall be unambiguously associated to a coordinate reference system either directly or through its containing geometry. The z coordinate of a point is typically, but not necessarily, represents altitude or elevation. The m coordinate represents a measurement. All Geometry classes described in this specification are defined so that instances of Geometry are topologically closed, i.e. all represented geometries include their boundary as point sets. This does not affect their representation, and open version of the same classes may be used in other circumstances, such as topological representations.
Status: unknown
Properties include: asWKT
Sub class of Spatial Extent
Has sub class Point sf:Point
OWL Class

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Class: time:Instant

Instant - See http://www.w3.org/TR/owl-time/
Status: unknown
Used with: atTime
Sub class of Temporal Entity time:TemporalEntity
OWL Class

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Class: step:KeyPoint

Key Point - Key Points delimits the extent of SpatiotemporalExtents and can also be used to represent important points of a trajectory.
Status: unknown
Used with: hasEndingPoint hasStartingPoint hasPoint
OWL Class

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Class: sf:Point

Point - A Point is a 0-dimensional geometric object and represents a single location in coordinate space. A Point has an x-coordinate value, a y-coordinate value. If called for by the associated Spatial Reference System, it may also have coordinate values for z and m. The boundary of a Point is the empty set.
Status: unknown
Used with: hasLocation
Sub class of Geometry sf:Geometry
OWL Class

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Class: step:QualitativeDescription

Qualitative Description - A Qualitative Description is used in situations when the Episode cannot be described by numeric values. This is also a point of extension of the ontology as other ontologies can be plugged here for extending it. For instance, one can define values such as "slow", "medium", or "fast" for speed episodes.
Status: unknown
Sub class of Semantic Description
OWL Class

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Class: step:QuantitativeValue

Quantitative Value - The value associated to the Episode. For instance, integer, decimal values. It is also associated with an Unit.
Status: unknown
Properties include: hasValue hasUnit
Sub class of Semantic Description
OWL Class

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Class: step:RawTrajectory

Raw Trajectory - Represent the raw data from trajectories. As there's no official support for ensuring sequential ordering of tuples, we advise putting sequential numbers into the URLs of fixes to be able to retrieve the spatial footprint of the trajectory. Another solution is querying using an ORDER BY statement that sorts by the time:Interval of each Fix that composes the RawTrajectory.
Status: unknown
Properties include: hasFix
Used with: hasRawTrajectory
OWL Class

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Class: step:SemanticDescription

Semantic Description - Each episode may have one or many semantic descriptions, which can be of two types: Qualitative or Quantitative.
Status: unknown
Used with: hasSemanticDescription
Has sub class Qualitative Description Quantitative Value step:QualitativeDescription step:QuantitativeValue
OWL Class

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Class: step:SpatialExtent

Spatial Extent - An extent determined only by spatial concepts (points, lines, polygons, etc). The usage of OGC Simple Features is a suggestion and can be exchanged by other ontologies.
Status: unknown
Sub class of Extent
Has sub class Geometry sf:Geometry
OWL Class

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Class: step:SpatiotemporalExtent

Spatiotemporal Extent - Spatiotemporal extents are delimited by KeyPoints and the properties hasStartingPoint and hasEndingPoint. Event-like episodes may be delimited by the property hasPoint.
Status: unknown
Properties include: hasStartingPoint hasPoint hasEndingPoint
Sub class of Extent
OWL Class

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Class: time:TemporalEntity

Temporal Entity - See http://www.w3.org/TR/owl-time/
Status: unknown
Sub class of Temporal Extent
Has sub class Instant time:Instant
OWL Class

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Class: step:TemporalExtent

Temporal Extent - An extent determined only by temporal concepts (interval, instant, etc). The usage of OWL Time is a suggestion and can be exchanged by other ontologies.
Status: unknown
Sub class of Extent
Has sub class Temporal Entity time:TemporalEntity
OWL Class

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Class: step:Trajectory

Trajectory - The agent's trajectory.
Status: unknown
Properties include: hasRawTrajectory
Used with: hasTrajectory
OWL Class

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Class: qu:Unit

Unit - A Unit is an abstract classifier that represents the [VIM] concept of "measurement unit" that is defined as "real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared to express the ratio of the two quantities as a number."
Status: unknown
Used with: hasUnit
OWL Class

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Properties

Property: geo:asWKT

asWKT - The WKT serialization of a geometry.
Status: unknown
Domain: Geometry sf:Geometry
Range: sf:WktLiteral
Datatype Property

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Property: step:atTime

atTime - Links the Fix or KeyPoint to a time instant.
Status: unknown
Domain:
Range: Instant time:Instant
Object Property
Functional Property

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Property: step:hasEndingPoint

hasEndingPoint - Links a Spatiotemporal extent to a KeyPoint that defines when and where the episode finishes.
Status: unknown
Domain: Spatiotemporal Extent
Range: Key Point
Object Property
Functional Property

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Property: step:hasEpisode

hasEpisode - Links a Feature of Interest to its corresponding Episodes.
Status: unknown
Domain: Feature of Interest
Range: Episode
Object Property

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Property: step:hasExtent

hasExtent - Links an episode to an extent.
Status: unknown
Domain: Episode
Range: Extent
Object Property

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Property: step:hasFeature

hasFeature - Links a Trajectory or Contextual Element to a Feature of Interest.
Status: unknown
Domain:
Range: Feature of Interest
Object Property

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Property: step:hasFix

hasFix - Links each Fix to its Raw Trajectory.
Status: unknown
Domain: Raw Trajectory
Range: Fix
Object Property

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Property: step:hasLocation

hasLocation - Links a Fix or a KeyPoint to a location.
Status: unknown
Domain:
Range: Point sf:Point
Object Property
Functional Property

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Property: step:hasPoint

hasPoint - Links any point of the trajectory to a spatiotemporal extent.
Status: unknown
Domain: Spatiotemporal Extent
Range: Key Point
Object Property

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Property: step:hasRawTrajectory

hasRawTrajectory - Links a trajectory to its own raw representation.
Status: unknown
Domain: Trajectory
Range: Raw Trajectory
Object Property
Functional Property

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Property: step:hasSemanticDescription

hasSemanticDescription - Links an episode to a description.
Status: unknown
Domain: Episode
Range: Semantic Description
Object Property

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Property: step:hasStartingPoint

hasStartingPoint - Links a Spatiotemporal extent to a KeyPoint that defines when and where the episode starts.
Status: unknown
Domain: Spatiotemporal Extent
Range: Key Point
Object Property
Functional Property

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Property: step:hasTrajectory

hasTrajectory - Links an Agent to a Trajectory.
Status: unknown
Domain: Agent
Range: Trajectory
Object Property
Inverse Functional Property

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Property: step:hasUnit

hasUnit - Links an Unit to a Quantitative Description.
Status: unknown
Domain: Quantitative Value
Range: Unit qu:Unit
Object Property
Functional Property

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Property: step:hasValue

hasValue - Links the value to a QuantitativeValue of an Episode.
Status: unknown
Domain: Quantitative Value
Range: xsd:anySimpleType
Datatype Property

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Property: step:relatesTo

relatesTo - Links an Episode to a ContextualElement.
Status: unknown
Domain: Episode
Range: Contextual Element
Object Property

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Acknowledgments

The authors would like to thank the French Ministry of Higher Education and Research (Ministère de l’Enseignement Supérieur et de la Recherche de la France – MESR).