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Fuzzy Pattern Trees for Regression and Fuzzy Systems Modeling. Robin Senge & Eyke Hüllermeier. WCCI 2010, Barcelona. Outline. Problem Setting Introduction to Fuzzy Pattern Trees (FPT) Learning Fuzzy Pattern Trees from Data Experiments Relation to Fuzzy Rule-based Systems
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Fuzzy Pattern Trees for Regression and Fuzzy Systems Modeling Robin Senge & Eyke Hüllermeier WCCI 2010, Barcelona
Outline • Problem Setting • IntroductiontoFuzzy Pattern Trees (FPT) • Learning Fuzzy Pattern Treesfrom Data • Experiments • Relation toFuzzyRule-based Systems • UsingFuzzy Pattern TreesforFuzzy System Modeling
Problem Setting Standard setting of supervised learning: • attribute-value representation of instances • let be input domains and be the output domain • input attribute domains discretized by fuzzy sets, e.g., low, medium and high • rescale to by model functional relationship, i.e.
Example: Wine Quality • aim: predicting quality of wine based on its ingredients (UCI) • input attributes: acidity, alcohol, sulfates, sulfur, ... • target (output) attribute is quality
Example Fuzzy Pattern Tree (FPT) wine quality 0.5 0.8 0.2 alcohol high MIN MAX • AVG 0.8 0.2 acidity low 0.8 0.3 acidity med sulfates med 10.2
Features of Fuzzy Pattern Trees high wine quality • interpretabilityofthe model class • modularity: recursivepartitioningofcritriainto sub-criteria • flexibilitywithoutthetendencytooverfitthedata • monotonicity in singleattributes • built-in featureselection alcohol high • AVG MIN MAX acidity low acidity med sulfates med
iteratively refining = growing up trees start with primitive pattern tree growing tree in a top-down manner selection based on tree performance measure check relative performance improvement Learning Fuzzy Pattern Trees from Examples A A B E D A E D B B A C B C MIN • AVG • AVG MIN MIN • AVG MAX MIN MAX • AVG MIN MAX • AVG • AVG • AVG A A B D D greedy beam search (details in thepaper) B C
Experiments Are Fuzzy Pattern Treescompetitive in termsofpredictiveaccuracy? • 12 data sets from UCI and STATLIB • 10-fold-cross validation • root mean squared error (RMSE) baseline algorithms • Linear Regression (LR) • Multi Layer Perceptron (MLP) • Support Vector Machine with linear kernel (SMO-lin) • Support Vector Machine with RBF kernel (SMO-rbf) • Fast decision tree learner with reduced error pruning (REPtree) • Fuzzy RuleLearnerby Wang & Mendel (FR)
Results Ranks accordingto RMSE PT-reg appearstobe (at least) competitive tobaseline algorithms.
Fuzzy Pattern Trees vs. Rule-basedFuzzy Systems • Fuzzy Pattern TreesarecloselyrelatedtoFuzzyRule-based Systems • fuzzy rules for property: low qualityIFhigh(acidity) ANDlow(alcohol) THENquality is lowIFlow(acidity) ANDmedium(sulfates) THENquality is lowIFhigh(alcohol) ANDmedium(sulfur)THENquality is low fuzzy rules for property: low quality Score(quality is low) = MAX { MIN {high(acidity), low(alcohol)},MIN {low(acidity), medium(sulfates)},MIN {high(alcohol), medium(sulfur)}} • fuzzy rules for property: low qualityIF MIN {high(acidity), low(alcohol)}THENquality is low IF MIN {low(acidity), medium(sulfates)} THENquality is low IF MIN {high(alcohol), medium(sulfur)}THENquality is low MIN MIN MIN low quality MAX aciditylow sulfatesmed alcoholhigh sulfurmed acidityhigh alcohollow
Fuzzy Systems Modeling • usually, not onlyonefuzzyseton but completefuzzypartition • let be the fuzzy sets on model functional relationships, i.e. high quality medium quality low quality F-AND AVG-OP AVG-OP F-AND F-OR sulfur low sulfate low acid high sulfate med alcohol med acid high acid low alcohol high
Fuzzy Systems Modeling contd. low quality high quality medium quality low quality medium quality F-AND AVG-OP AVG-OP F-AND F-OR high quality sulfur low sulfate low acid high sulfate med alcohol med acid high acid low alcohol high
Conclusions • Fuzzy Pattern Trees have been introduced as a new model class for regression and fuzzy systems design. • They do have several interesting features (interpretability , monotonicity, flexibility, feature selection). • Data-driven model construction: WecanlearnFuzzy Pattern Trees from data. • Regression withFuzzy Pattern Treesiscompetitive to state-of-the-artalgorithms in termsofpredictiveaccuracy. Formoreinformationsearchthe web for„kebimarburg“.