Measure is related to Level. Level is related to Balanced. 
Low is related to Vertical. Vertical is related to Wall. you are likely to find Shelf in/at/on Wall. you are likely to find Shelf in/at/on Bedroom. 
Measure <--RelatedTo--> Level <--RelatedTo--> Balanced 
Low <--RelatedTo--> Vertical <--RelatedTo--> Wall <--AtLocation-- Shelf --AtLocation--> Bedroom 