About Sub-Term Mapping Tools

Sub-Term Mapping Tools (STMT) is a generic tool set that provides comprehensive sub-term related features for NLP applications with Java APIs and command line tools. It is used to find the longest prefix, prefixes, sub-terms, and synonymous sub-term substitutions in query expansion. There are six major components used in STMT:

• Corpus: the collection of terms on the specific interest of the project. It is stored in a tree structure in STMT with each term as a branch in the tree and each word in the term as a node in the branch.
• Sub-term: a sub-term is a term that is a subset of another term in the corpus
• Prefix sub-term: a sub-term starts with the beginning of the input term
• The longest prefix sub-term: the longest sub-term starts with the beginning of the input term
• Sub-term patterns: pattern permutations with specified sub-term numbers
• Synonymous sub-term substitutions: all permutations of new terms by substituting synonymous sub-terms

They are illustrated by the following example:

• Corpus:

  Terms	Synonymous Terms
  chronic	chron|long-term|persistent|recurrent periodic|relapsing
  infectious	communicable|contagious|infection
  otitis externa	auditory|auditory canal|aural|ear
  ...	...

• Input term:
  otitis externa, chronic infectious

• Sub-terms (3):
  • otitis externa
  • chronic
  • infectious

• Prefix sub-term (1):
  • otitis externa

• The longest prefix sub-term (1):
  • otitis externa

• Sub-term Patterns (8):
  • Zero sub-term patterns (1):
    • otitis externa chronic infectious
  • One sub-term patterns (3):
    • otitis externa chronic infectious
    • otitis externa chronic infectious
    • otitis externa chronic infectious
  • Two sub-term patterns (3):
    • otitis externa chronic infectious
    • otitis externa chronic infectious
    • otitis externa chronic infectious
  • Three sub-term patterns (1):
    • otitis externa chronic infectious

• Synonymous sub-term substitutions (117 = 12 + 47 + 60):
  • Synonymous sub-term substitutions with one sub-term (12 = 4 + 5 + 3):
    • otitis externa chronic infectious (4)
      • auditory chronic infectious
      • auditory canal chronic infectious
      • aural chronic infectious
      • ear chronic infectious
    • otitis externa chronic infectious (5)
      • otitis externa chron infectious
      • otitis externa long-term infectious
      • otitis externa persistent infectious
      • otitis externa relapsing infectious
      • otitis externa recurrent periodic infectious
    • otitis externa chronic infectious (3)
      • otitis externa chronic communicable
      • otitis externa chronic contagious
      • otitis externa chronic infection
  • Synonymous sub-term substitutions with two sub-term patterns (47 = 20 + 12 + 15):
    • otitis externa chronic infectious (20 = 4 x 5)
    • otitis externa chronic infectious (12 = 4 x 3)
    • otitis externa chronic infectious (15 = 5 x 3)
  • Synonymous sub-term substitutions with three sub-term patterns (1):
    • otitis externa chronic infectious (60 = 4 x 5 x 3)