• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Chapter 4
 

Chapter 4

on

  • 197 views

 

Statistics

Views

Total Views
197
Views on SlideShare
197
Embed Views
0

Actions

Likes
0
Downloads
0
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Chapter 4 Chapter 4 Presentation Transcript

    • Dependencies in knowledge Chapter 4
    • Contents
      • Introduction
      • Dependency of knowledge
      • Partial Dependency of Knowledge
    • 1.Introduction
      • P Q :
          • Q is derivable from P ,
          • Q depends on P
      • Developing theories can be is based on discovering inference rules of the form “if…then…”
      • Knowledge Q is derivable from Knowledge P , if all elementary categories of Q can be defined in terms of some elementary categories of P
    • 2.Dependency of knowledge
      • Let K=( U ,R) be a knowledge base and let
          • Knowledge Q depends on Knowledge P iff
          • Knowledge P and Q are equivalent ( ), iff and
          • Knowledge P and Q are independent ( ), iff neither nor hold.
      iff
      • Example 1:
        • Given knowledge P, Q
        • U/P= {{1,5}{2,8}{3}{4}{6}{7}}
        • U/Q= {{1,5}{2,7,8}{3,4,6}}
      U|P U|Q then
    • Proposition
    • Proposition
    • Proposition
    • 3.Partial Dependency of Knowledge
      • Definition :
      • When only part of knowledge Q is derivable from knowledge P, the derivation become partial .
      • Let K=( U ,R) be a knowledge base and . Knowledge Q depends in a degree k (0 ≤ k ≤ 1 ) from knowledge P(P ⇒ k Q) iff
      • If k = 1 we say that Q depends totally on P.
      • If k < 1 we say that Q depends partially ( in a degree k ) on P.
      • Example 2:
      • U/Q= {{1}{2,7}{3,6}{4}{5,8}}
      • U/P= {{1,5}{2,8}{3}{4}{6}{7}}
      • POS P (Q) = {3,4,6,7}
      • the degree of dependency between Q and P
      • (P⇒ 0.5 Q )
    • Propositions