W3C Video on the Web Workshop12-13 December 2007, San Jose, California

Video on the Semantic Sensor Web

Amit Sheth with Cory Henson,Prateek Jain, Josh Pschorr and Terry Rapoch

LexisNexis Ohio Eminent ScholarKno.e.sis Center, Wright State University

http://knoesis.wright.edu

Outline

1. Background on the Sensor Web

2. Introducing the Semantic Sensor Web

3. Prototyping the Semantic Sensor Web

Background on the Sensor Web Sensor Web Enablement

OGC MissionOGC Mission

To lead in the To lead in the development, development,

promotion and promotion and harmonization of harmonization of

open spatial open spatial standardsstandards

Open Geospatial Consortium

• Consortium of 330+ companies, government agencies, and academic institutes

• Open Standards development by consensus process

• Interoperability Programs provide end-to-end implementation and testing before spec approval

• Standard encodings, e.g.– GeographyML, SensorML, Observations &

Measurements, TransducerML, etc.• Standard Web Service interfaces, e.g.

– Web Map Service– Web Feature Service– Web Coverage Service– Catalog Service– Sensor Web Enablement Services (Sensor

Observation Service, Sensor Alert Service, Sensor Process Service, etc.)

http://www.opengeospatial.org/projects/groups/sensorweb

Network ServicesNetwork Services

Vast set of users and applicationsConstellations of heterogeneous sensors

Weather

ChemicalDetectors

BiologicalDetectors

Sea State

Surveillance

Airborne

Satellite

• Distributed self-describing sensors and related services

• Link sensors to network and network-centric services

• Common XML encodings, information models, and metadata for sensors and observations

• Access observation data for value added processing and decision support applications

• Users on exploitation workstations, web browsers, and mobile devices

Sensor Web Enablement

Sensor Web Enablement

http://www.opengeospatial.org/projects/groups/sensorweb

GeographyML (GML)

TransducerML (TML)

Observations &

Measurements (O&M)

Information Model for Observations and Sensing

Sensor and Processing Description Language

Multiplexed, Real Time Streaming Protocol

Common Model for Geography Systems and Features

SensorML (SML)

Sam Bacharach, “GML by OGC to AIXM 5 UGM,” OGC, Feb. 27, 2007.

SWE Languages and Encodings

CatalogService

SOS

SAS

SPS

Clients

Access Sensor Description and

DataCommand and Task Sensor

Systems

Dispatch Sensor Alerts to

registered Users

Discover Services, Sensors,

Providers, Data

Accessible from various types of

clients from PDAs and Cell Phones to

high end Workstations

Sam Bacharach, “GML by OGC to AIXM 5 UGM,” OGC, Feb. 27, 2007.

SWE Components – Web Services

Introducing the Semantic Sensor Web

Semantic Sensor Web

What is the Semantic Sensor Web?

• Adding semantic annotations to existing standard Sensor Web languages in order to provide semantic descriptions and enhanced access to sensor data

• This is accomplished with model-references to ontology concepts that provide more expressive concept descriptions

• By using model-references to link SML annotated sensor data with concepts within an OWL-Time ontology we attain a representation of temporal semantics on sensor data

Model Reference

XLink • Used for describing links between resources in XML

documents.  • Several  important attributes within XLink include:

– type: describes the element type of the link (i.e., simple, extended)– role: semantic attribute that describes the meaning of resources

within the context of a link– href: locator attribute that supplies the URI needed to find a remote

resource  

Other Model Reference Languages• SAWSDL: Defines mechanisms to add semantic annotations to

WSDL and XML-Schema components (W3C Recommendation)• SA-REST: Defines mechanisms to add semantic annotations to

REST-based Web services.

W3C, XML Linking Language, http://www.w3.org/TR/xlink

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Model Reference (SensorML)

Instant

Interval

OWL-Time Ontology

Semantic Query

Semantic Temporal Query

• Model-references from SML to OWL-Time ontology concepts provides the ability to perform semantic temporal queries

• Supported semantic query operators include:– contains: user-specified interval falls wholly within a sensor

reading interval (also called inside)– within: sensor reading interval falls wholly within the user-

specified interval (inverse of contains or inside)– overlaps: user-specified interval overlaps the sensor reading

interval• Example SPARQL query defining the temporal operator ‘within’

Prototyping the Semantic Sensor Web

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Storage QueryExtraction & Metadata Creation

VideoConversion

Filtering& OCR

SML AnnotationGeneration

Time & Dateinformation

ConvertedVideos

SML(Xindice)

OWL-Time(Jena)

UI

SML Interface

OWL-TimeInterface

AVI

OWL-Time AnnotationGeneration

Google Maps

JSP

Architecture

Data Collection

YouTube

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Temporal Data Extraction

Channel Minimal Suppression 1

8-neighbor median for ‘bad’ pixels 1

Temporal Minimal Suppression 2

Binarization via adaptive threshold 1

Tesseract OCR engine

Regular Expression parsingSensorML output

1. https://research.microsoft.com/~xshua/publications/pdf/2002_ISCAS_TimeStampOCR.pdf2. http://www.informedia.cs.cmu.edu/documents/vocr_ieee98.pdf

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Prototype Application

http://knoesis.wright.edu/library/demos/ssw/prototype.htm

Conclusion

Future Work

• Incorporation of spatial ontology in order to include spatial analytics and query (perhaps with OGC GML Ontology or ontology developed by W3C Geospatial Incubator Group - GeoXG)

• Thematic query with keyword search through YouTube API and model reference to domain ontology

• Extension of SPARQL with enhanced spatiotemporal analytics and query

• Integration of framework with emergent applications, including video on mobile devices running Android OS

W3C, XML Linking Language, http://www.w3.org/TR/xlink

• Kno.e.sis project on Semantic Sensor Web: http://knoesis.wright.edu/projects/sensorweb/

• Open Geospatial Consortium, Sensor Web Enablement WG, http://www.opengeospatial.org/projects/groups/sensorweb

• W3C, Time Ontology in OWL, http://www.w3.org/TR/owl-time/

• W3C, Geospatial Incubator Group, http://www.w3.org/2005/Incubator/geo/

• Amit Sheth et al., SA-REST: Semantically Interoperable and Easier-to-Use Services and Mashups, IEEE Internet Computing, November/December 2007 (Vol.11, No.6) pp.91-94. DOI: http://doi.ieeecomputersociety.org/10.1109/MIC.2007.133

• W3C, Semantic Annotations for WSDL and XML Schema, http://www.w3.org/TR/sawsdl/

• W3C, XML Linking Language, http://www.w3.org/TR/xlink/

• Google Code, Tesseract, http://code.google.com/p/tesseract-ocr/

References