https://w3id.org/framester/conceptnet5/data/en/personal_flotation_device <https://w3id.org/framester/conceptnet5/schema/DerivedFrom> <https://w3id.org/framester/conceptnet5/data/en/flotation.n> <https://w3id.org/framester/conceptnet5/schema/IsA> <https://w3id.org/framester/conceptnet5/data/en/non_power_device> <https://w3id.org/framester/conceptnet5/data/en/safety_device> risorse dalla linked data cloud