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Semantic-Based Workflow CompositionSemantic-Based Workflow Compositionfor Video Processing in the Gridfor Video Processing in the Grid
Gayathri Nadarajan,Gayathri Nadarajan,
Yun-Heh Chen-Burger, James MaloneYun-Heh Chen-Burger, James Malone
Centre for Intelligent Systems and their ApplicationsSchool of Informatics
University of EdinburghScotland
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Introduction - EcoGridIntroduction - EcoGrid
Utilises state-of-the-art Grid technologies to establish an infrastructure for ecological research in several locations in Taiwan.
Scientists can conduct data acquisition, data analysis and data sharing on this platform.
Divided into four components; network, data streaming, data management and workflow enactment.
Collaboration between National Centre for High-Performance Computing (NCHC), Taiwan and Artificial Intelligence Applications Institute (AIAI), University of Edinburgh on workflow enactment for EcoGrid.
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Ecological and Technical MotivationsEcological and Technical Motivations
Problem:- Vast amount of valuable and continuous real-time data of varying quality is collected over 3 years, unanalysed. - Manual processing is time-consuming.
1 minute’s clip will take 15 minutes to analyse, thus 1 year’s recording will cost human experts 15 years’ effort x 3 under water cameras = 45 years.
Impractical situation and more appropriate automation methods must be deployed.
Semi-automated and automated way to speed up this process.
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RequirementsRequirements
Process Automation:
- Process model for video annotation:
Performance-Based Selection. Iterative Processing. Adaptive, Flexible and Generic Architecture. Semantic-Based Compatibility.
Key framedetection Segmentation Recognition Annotation
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Related WorkRelated Work
Existing Grid workflow systems:
- Pegasus
- Triana
- Taverna
- Kepler
- Askalon
- JOpera
Limitations of current solutions for flexible workflow composition for complex video processing tasks.
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ExampleExample
“Detect at least one tiger fish in high brightness”
Goal: Detection
Constraints: Occurrence = at_least_one;
Brightness = high
Process Library Representation:detect_presence(X) :-
pre_process(X), feature_extraction(X), segmentation(X), classification(X).
pre_process(tiger_fish) :-
keyframe_detection, enhancement.
Constraint Qualifierin Goal Ontology
Illumination_level in Domain Ontology
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Walkthrough IWalkthrough I
User (ecologist) interacts with system by providing high level goals and constraints as input.
Goal will match that in the Goal ontology.
Constraints will match those in the Domain ontology and will determine the video clip to be fetched.
The Planner will look for a sequence of processes for execution using task decomposition.
Sequence of processes constitute the workflow composition.
Instances of processes and their subtasks are contained in the process library.
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Walkthrough IIWalkthrough II
Each subtask will be matched with a video/image processing operation contained in the Capability ontology. The tool to execute each operation is also contained in the Capability ontology.
In cases where more than one tool is available to perform the subtask, the tool with the best performing capability is selected.
A set of tools to perform VP task is now obtained.
VP tools may now work on the video clip directly.
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Video Processing Tools/LibrariesVideo Processing Tools/Libraries
Open Computer Vision Library (OpenCV) LTI library (C++) HTK (HMM classifier) Lib SVM ITK (medical imaging) STL (C++)
Readily available but not Grid-compatible.
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DiscussionDiscussion
Work in progress- Understand video processing tools available.- Build goal, domain and capability ontologies.- Keep terminologies non-technical for ecologists but may have technical implication in underlying mechanism, e.g. “pitch dark” means “brightness” level in the range 0-25.
Build a prototype based on walkthrough
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ContributionsContributions
Grid workflow technology with semantic capabilities + AI Planning and CBR.
Vision - specialised tools used in workflow could help provide reasonable solutions for automatic video processing, e.g. annotation.
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ReferencesReferences
EcoGrid, National Centre for High Performance, Taiwan, 2006. http://ecogrid.nchc.org.tw/
Workflow enactment in the EcoGrid, AIAI, University of Edinburgh, 2006. http://www.aiai.ed.ac.uk/~jessicac/project/NCHC
Y-H Chen-Burger, F-P Lin. “A Semantic Based Workflow Choreography for Integrated Sensing and Processing”. In Procs. CNNA 2005.
G. Nadarajan, Y-H Chen-Burger, J Malone. “Semantic Grid Services for Video Analysis”. In Procs. SerComp06.
D. D. O’Roure, N. R. Jennings, N. R. Shaldbolt. “The Semantic Grid: Past, Present and Future”. In Procs. the IEEE Vol. 93, Issue 3, 2005.
J. Yu, R. Buyya. “A Taxonomy of Workflow Systems for Grid Computing”. Journal of Grid Computing, 2006.
OpenCV. http://sourceforge.net/projects/opencvlibrary
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Proposed Framework – Design LayerProposed Framework – Design Layer
Process Manager is responsible for composing sequence of processes to be executed based on available tools.
- Planning component
- CBR component
Ontologies give meaning to process and keep goals separate from capabilities.
- Goal
- Domain
- Tool/Capability
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Proposed Framework – Workflow LayerProposed Framework – Workflow Layer
Main interface between design and processing layers. Workflow enactor acts as interpreter of events that
occur within system.
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Proposed Framework – Processing LayerProposed Framework – Processing Layer
Consists of a set of image and video processing tools. Functions of tools represented in capability ontology in
Design Layer. Once a workflow has been established, tools may work
directly on videos. Depending on quality of video and task at hand, each
tool will work on varying level of accuracy. Feedback from domain expert would be useful. Use of ML techniques to assist with performance
measure predictions for image and video processing tools.
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The Semantic Grid The Semantic Grid
The Grid is aimed at enabling resource sharing and coordinated problem-solving between computers and people in a distributed and heterogeneous manner.
The Semantic Grid is an extension of current Grid whereby information and services are given well-defined and explicitly represented meaning, i.e. the application of Semantic Web technologies to the Grid.
Requires means for facilitating the composition of multiple resources and mechanisms for creating and enacting these in a distributed manner, i.e. composing and executing complex workflows.
Improvement of Grid workflow systems with the incorporation of semantic capabilities.