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MediaHub: An Intelligent MultiMedia Distributed Platform Hub. MediaHub. Glenn Campbell, Tom Lunney & Paul Mc Kevitt School of Computing and Intelligent Systems Faculty of Engineering University of Ulster, Magee Campus Derry/Londonderry Northern Ireland
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MediaHub: An Intelligent MultiMedia Distributed Platform Hub MediaHub Glenn Campbell, Tom Lunney & Paul Mc Kevitt School of Computing and Intelligent Systems Faculty of Engineering University of Ulster, Magee Campus Derry/Londonderry Northern Ireland {Campbell-g8, TF.Lunney, P.McKevitt} @ulster.ac.uk
Outline • Research objectives • Related research • Architecture of MediaHub • Dataflow • Semantic representation/storage • Communication • Decision-making in MediaHub • Future development
Research Objectives • Interpret/generate semantic representations of multimodal input/output • Perform fusion and synchronisation of multimodal data (decision-making) • Implement and evaluate a multimodal platform hub (MediaHub)
Key research problems • Semantic representation and storage? • Communication? • Decision-making?
Related Research • CORBA (Vinoski 1993) • COLLAGEN (Rich et al. 1997) • Open Agent Architecture (Cheyer et al. 1998) • Chameleon (Brøndsted et al. 1998) • Ymir (Thórisson 1999) • Interact (Jokinen et al. 2002) • SmartKom (Wahlster 2003, 2006) • Psyclone (Thórisson et al. 2005) • Hugin (Jensen 2001)
Dataflow in MediaHub Marked-up MultiModal Input/Output (XML) Dialogue Manager MediaHub Whiteboard (EMMA) Hugin Decision Engine Decision-Making Module
Semantic Representation • XML used for input/output data • Well established standard mark-up language • Allows MediaHub to be integrated into other existing multimodal systems • XML input is validated against a Document Type Definition (DTD) • Using EMMA (Extensible MultiModal Annotation mark-up language) for semantic representation • EMMA is a derivative of XML • EMMA is suited to representing confidences relating to multimodal data (confidence tag)
Example XML input file <?xml version="1.0"?> <!DOCTYPE multimodal SYSTEM "C:\Psyclone2\MediaHubInput.dtd"> <hypotheses> <hypothesis1> <language> <match> <yes>0.8</yes> <no>0.2</no> </match> <confidence> <yes>0.9</yes> <no>0.1</no> </confidence> </language> <gesture> … … </gesture> <referentObject> Object 1 </referentObject> </hypothesis1> <hypothesis2> …
Semantic Storage • Blackboard-based method of semantic storage • Marked-up input in EMMA format stored on central whiteboard (MediaHub Whiteboard) • All input/output messages in MediaHub are stored on whiteboard and can be accessed at any stage in the decision-making process • Whiteboard and Dialogue Manager form kernel of MediaHub
Communication • MediaHub uses Psyclone for distributed processing • Psyclone uses OpenAIR specification for communication • Modules of MediaHub communicate by passing messages through MediaHub Whiteboard • Implements a publish-subscribe architecture • For example, Decision-Making Module registers for messages of type *input* • All messages relating to input posted on whiteboard will automatically be sent to Decision-Making Module • Module registration is done in XML specification file, called PsyProbe, run automatically at start-up
PsySpec Example <executable name="DMM" consoleoutput="yes"> <sys ostype="Win32"> java -cp .;JavaOpenAIR.jar DMM psyclone=%host%:%port% name=%name% </sys> </executable> <spec> <triggers from="any" allowselftriggering="no"> <trigger type="*input*"/> <trigger type="MediaHub.shutdown"/> </triggers> <posts> <post to="MediaHub_Whiteboard" type="dmm.register" /> </posts> </spec> </module>
Decision-making • MediaHub employs Bayesian decision-making over multimodal data • Bayesian networks developed using Hugin software tool (Jensen 2001) • Networks are accessed using Hugin API (Java) • A unique approach to decision-making in an intelligent multimedia distributed platform hub
Hugin • Tool for implementing Bayesian Networks as CPNs (Causal Probabilistic Networks) • Hugin GUI • Graphical user interface to Hugin decision engine • Hugin API • Library implemented in Java • Allows programs to implement Bayesian Networks for decision-making
Exercise Diet ‘Diet’ and ‘Exercise’ nodes have influence over ‘Weight Loss’ node Weight Loss Bayesian Networks • AKA Bayes nets, Causal Probabilistic Networks (CPNs), Bayesian Belief Networks • Consists of nodes and directed edges between nodes • Node represents a variable • Influence between nodes represented by edges
MediaHub Example Network • G1-3 represents the belief that the user is referring to Objects 1-3, based on gesture input • L1-3 represents the belief that the user is referring to Objects 1-3, based on language input • CG1-3 and CL1-3 represent the confidence associated with G1-3 and L1-3
Bayesian Network Design Process • Characterise decision-making scenarios • Design Bayesian networks for decision-making scenarios • Use the Hugin GUI to build Bayesian networks and complete conditional probability tables • Run and test networks, making changes to networks and tables as required • Develop Java code that will open, edit and run the Bayesian network using the Hugin API
Decisions in MediaHub • Input: • Determining semantic content of input • Fusing semantics of input • Resolving ambiguity at input • Output: • Synchronising multimodal output • Best modality for output
Input example “Copy all files from the ‘process control’ folder of this computer to a new folder called ‘check data’ on that computer”.
Output Example “This is the route from Paul’s office to Tom’s office”. T P
Conclusion • An intelligent multimodal distributed platform hub called MediaHub is under development • MediaHub interprets/generates semantic representations of multimodal input and output • MediaHub performs fusion and synchronisation of multimodal data • MediaHub provides a new method of decision-making within a distributed platform hub
Future development • Define all necessary decisions for example scenarios • Develop Bayesian decision-making using Hugin API (Java) • Develop a GUI to illustrate the functionality of MediaHub • Test MediaHub on example scenarios • Compare MediaHub to other systems • Write thesis