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projects [2013/10/21 03:15] pszwed [Fuzzy Semantic Petri Nets] |
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- | ====== Projects ====== | ||
- | ===== Fuzzy Semantic Petri Nets ===== | ||
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- | Fuzzy Semantic Petri Nets (FSPN) are Petri nets coupled with an underlying fuzzy ontology. | ||
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- | *The fuzzy ontology stores facts about a development of a certain complex event (or a process). They are expressed as fuzzy unary or binary relations between participating objects. The ontology ABox is updated with new observations. | ||
- | *The Petri net defines a scenario of an event (or a process, if you like), its places correspond to the scenario steps | ||
- | *Tokens in FSPN represent combinations of objects participating in the event. They are attributed with weights expressing likelihood of a scenario step occurrence | ||
- | *Guards in FSPN are conjunctions of fuzzy predicates referencing the assertions in the coupled ontology | ||
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- | FSPN were applied to the problem of video event recognition. In the presented example an abandonned laguagge is correctly detected. (The event scenario and the dataset were published at [[http://www.cvg.rdg.ac.uk/PETS2006/|PETS 2006 Workshop]]) . | ||
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- | Scenario: | ||
- | -A man ''x'' enters the scene and is still for some time | ||
- | -Then he takes his rucksack ''y'' off and puts it on the floor. He stays close to it for some time. The rucksack should not move ''isStill(y)''. | ||
- | -Next, he leaves the rucksack unattended (the object is classified //unattended// if the distance between it and its owner is greater than 3 m). The luggage should remain still. | ||
- | -Finally, the man disappears and the luggage rest still and unattended (possible bomb planting) | ||
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- | The listed above steps correspond to the places of FSPN specifying the scenario. Transition guards define the conditions that should be satisfied to reach the next step. | ||
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- | {{:projects:pets-scenario.png?600}} | ||
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- | The clip below shows the GUI of a software, that internally usess the FSPN approach to recognize video events. | ||
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- | <html> | ||
- | <iframe width="560" height="315" src="//www.youtube.com/embed/_hArl9i20TY" frameborder="0" allowfullscreen></iframe> | ||
- | </html> |