Download presentation
Presentation is loading. Please wait.
Published byLily Barrett Modified over 8 years ago
1
Richard Jensen and Chris Cornelis Chris Cornelis Chris Cornelis Ghent University, Belgium Richard Jensen Richard Jensen Aberystwyth University, UK Fuzzy-Rough Instance Selection
2
Richard Jensen and Chris Cornelis Outline The importance of instance selection Rough set theory Fuzzy-rough sets Fuzzy-rough instance selection Experimentation Conclusion
3
Richard Jensen and Chris Cornelis Knowledge discovery The problem of too much data Requires storage Intractable for data mining algorithms Removing data that is noisy or irrelevant Instance selection
4
Richard Jensen and Chris Cornelis Rough set theory Rx is the set of all points that are indiscernible with point x Upper Approximation Set A Lower Approximation Equivalence class Rx
5
Richard Jensen and Chris Cornelis Fuzzy-rough sets Approximate equality Handle real-valued features via fuzzy tolerance relations instead of crisp equivalence Better noise and uncertainty handling Focus has been on feature selection, not instance selection
6
Richard Jensen and Chris Cornelis Fuzzy-rough sets Parameterized relation Fuzzy-rough definitions:
7
Richard Jensen and Chris Cornelis Instance selection: basic idea Not needed Remove objects to keep the underlying approximations unchanged
8
Richard Jensen and Chris Cornelis Instance selection: basic idea Remove objects to keep the underlying approximations unchanged
9
Richard Jensen and Chris Cornelis FRIS-I
10
Richard Jensen and Chris Cornelis FRIS-II
11
Richard Jensen and Chris Cornelis FRIS-III
12
Richard Jensen and Chris Cornelis Experimentation: setup
13
Richard Jensen and Chris Cornelis Results: FRIS-I (heart) (214 objects, 9 features)
14
Richard Jensen and Chris Cornelis Results: FRIS-II (heart)
15
Richard Jensen and Chris Cornelis Results: FRIS-III (heart)
16
Richard Jensen and Chris Cornelis Conclusion Proposed new techniques for instance selection based on fuzzy-rough sets Managed to reduce the number of instances significantly, retaining classification accuracy Future work Many possibilities for novel fuzzy-rough instance selection methods Comparisons with non-rough techniques Improving the complexity of FRIS-III Combined instance/feature selection
17
Richard Jensen and Chris Cornelis WEKA implementations of all fuzzy-rough methods can be downloaded from:
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.