a blackboard globally recast as an interpreter - jairam kamath | website for students | vtu notes |...
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A Blackboard Globally Recast as an Interpreter
- Jairam Kamath
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A Blackboard Globally Recast as an Interpreter
• The blackboard model of problem solving is a highly structured special case of opportunistic problem solving.
• The solution space is organized into several application-dependent hierarchies and the domain knowledge partitioned into independent modules of knowledge that operate on knowledge within and between levels.
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Basic architecture of a blackboard system
Three Major parts:• Knowledge sources• The blackboard data structure• Control
Example: HEASRSAY – II
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----> Control flow____ Data flow
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----> Control flow____ Data flow
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-Blackboard
• HEARSAY-II speech recognition system.• The blackboard structure is a six- to eight-level hierarchy in
which each level abstracts information on its adjacent lower level.
• blackboard elements represent hypotheses about the interpretation of an utterance.
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-Knowledge Sources
• Knowledge sources correspond to such tasks as segmenting the raw signal, identifying phonemes, generating word candidates, hypothesizing syntactic segments, and proposing semantic interpretations.
• Each knowledge source is organized as a condition part that specifies when it is applicable and an action part that processes relevant blackboard elements and generates new ones.
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-Control
• The control component is realized as a blackboard monitor and a scheduler.
• The scheduler monitors the blackboard and calculates priorities for applying the knowledge sources to various elements on the blackboard.
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----> Control flow____ Data flow
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Interpreter View
• The complexity arises because it is now illustrating two concepts: The blackboard model and realization of that model by a virtual machine.
• The blackboard model can be recovered by suppressing the control mechanism and regrouping the conditions and actions into knowledge sources.
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Interpreter View
• The interpretation engine includes several components like: the blackboard monitor, the focus of control database, and the scheduler, but also the actions of the knowledge sources.
• The scheduling queue corresponds roughly to the control state.
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Conclusion
• We see a system initially designed with one model (blackboard, a special form of repository), then realized through a different model (interpreter).
• The view as an interpreter is a different aggregation of components from the view as blackboard.
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SThank You
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