450 likes | 701 Views
Computational Intelligence. John Sum Institute of Technology Management National Chung Hsing University Taichung, Taiwan ROC. OUTLINE. Historical Background Computational Intelligence Example Problems Methodology Model Structure Model Parameters Parametric Estimation Discussion
E N D
Computational Intelligence John Sum Institute of Technology Management National Chung Hsing University Taichung, Taiwan ROC
OUTLINE • Historical Background • Computational Intelligence • Example Problems • Methodology • Model Structure • Model Parameters • Parametric Estimation • Discussion • Conclusion Computational Intelligence
HISTORY Computational Intelligence
HISTORY • 1940 – First computing machine • 1957 – Perceptron (First NN model) • 1965 – Fuzzy Logic (Rules) • 1960s – Genetic Algorithm • 1970s – Evolutionary Computing Computational Intelligence
HISTORY • 1980s • Neural Computing • Swarm Intelligence • 1990s (Hybrid) • Fuzzy Neural Networks • NFG, FGN, GNF, etc Computational Intelligence
CI IS SC HISTORY • Beyond 1990s: Research areas converge • Computational Intelligence • Softcomputing • Intelligent Systems • Covering • Adaptive Systems • Fuzzy Systems • Neural Networks • Evolutionary Computing • Data Mining AS FS DM EC NN SA PSO GA MCMC SL Computational Intelligence
COMPUTATIONAL INTELLIGENCE • Computational Intelligence • Heuristic algorithms (or models) such as in fuzzy systems, neural networks and evolutionary computation. • Techniques that use Simulated annealing, Swarm intelligence, Fractals and Chaos Theory, Artificial immune systems, Wavelets, etc. Computational Intelligence
COMPUTATIONAL INTELLIGENCE • Goal: Problem Solving • Financial forecast • Customer segmentation (CRM) • Supply chain design (SCM) • Business process re-engineering • System control • Pattern recognition • Image compression • Homeland security Computational Intelligence
COMPUTATIONAL INTELLIGENCE • Underlying structure of the model is unknown, or the model is known but it is too complicated • Example: DJI versus HIS (Time Series) • Define system structure • NL model (NN, ODE, etc.) • Rule-based system • Parametric estimation • Deterministic search (Gradient descent or Newton’s method) • Stochastic search (SA or MCMC) Computational Intelligence
COMPUTATIONAL INTELLIGENCE • Underlying model structure is known • Example: Manufacturing process (SCM) • Define the objective to be maximized • Examples: Completion time, Cost, Profit • Optimization • Linear programming, ILP, NLP • Deterministic search (Gradient descent or Newton’s method) • Stochastic search (SA or MCMC) Computational Intelligence
EG1: Nonlinear Dynamic System Computational Intelligence
EG2: Nonlinear Function Computational Intelligence
EG3: Car Price • Predict the price of a car based on • Specification of an auto in terms of various characteristics • Assigned insurance risk rating • Normalized losses in use as compared to other cars • Number of attributes: 25 • Missing values: Yes! Computational Intelligence
EG3: Car Price Computational Intelligence
EG4: Purchasing Preference Structural Equation Model Bayesian Network Feedforward Network Fuzzy Logic Computational Intelligence
EG5: Financial Time Series Computational Intelligence
EG5: Financial Time Series • What would happen in the next trading day? (Time series prediction problem) • Closing value • Open value • UP or DOWN • Time series prediction + trading rules • What should I do tomorrow? HOLD, SELL or BUY • When should I BUY and SELL? Computational Intelligence
Remarks on EG1 ~ EG5 Computational Intelligence
COMPUTATIONAL INTELLIGENCEStatement of Problem • Given a set of data collected (or measured) from a system (probably an unknown system), devise a model (by whatever structure, technique, method in CI) that mimics the behavior of that system as ‘good’ as possible. • Making use of the devised model to • (1) interpret the behavior of the system, • (2) predict the future behavior of the system, • (3) control the behavior of the system, • (4) make money. Computational Intelligence
METHODOLOGY • Step 1: Data Collection • Experiments or measurements • Questionnaire • Magazine • Public data sets • Step 2: Model Structure Assumption • IF it is known, SKIP this step. • ELSE, DEFINE a model structure Computational Intelligence
METHODOLOGY • Step 3: Parametric Estimation • Gradient descent • Newton’s method • Exhaustive search • Genetic algorithms (*) • Evolutionary algorithms (*) • Swarm intelligence • Simulated annealing (*) • Markov Chain Monte Carlo (*) Computational Intelligence
METHODOLOGY • Step 4: Model Validation (is it a reasonable good model) • Hypothesis test • Validation/Testing set • Leave one out validation • Step 5: Model Reduction (would there be a simpler model that is also reasonable good) • AIC, BIC, MDL • Pruning (using testing set) Computational Intelligence
METHODOLOGY • Beyond Model Reduction • Any redundant input • Any redundant sample (or outlier) • Any better structure (alternative) • How do we determine a ‘good’ model Computational Intelligence
Perceptron Multilayer Perceptron (MLP or BPN) Adaptive Resonance Theory Model (ART) Competitive Learning (CL) Hopfield Network, Associative Network Bidirectional Associative Model (BAM) Recurrent Neural Network (RNN) Boltzmann Machine Brain-State-In-A-Box (BSB) Radial Basis Function Network (RBF Net) Bayesian Networks Self Organizing Map (SOM or Kohonen Map) Learning Vector Quantization (LVQ) Support Vector Machine (SVM) Support Vector Regression (SVR) PCA, ICA, MCA Winner-Take-All Network (WTA) Spike neural networks Remarks Not all of them is able to learn, eg BSB, WTA Might need to combine two structures to solve a single problem Multiple definitions on the ‘neuron’ NN MODEL STRUCTURES Computational Intelligence
NN MODEL STRUCTURES • Supply Chain Management (Optimization Problem) • Hopfield Network • Customer Segmentation (Clustering Problem) • CL, SOM, LVQ, ART • Dynamic Systems Modeling • RNN, Recurrent RBF • Car Price/NL Function (Function Approximation) • MLP, RBF Net, Bayesian Net, SVR, +SOM/LVQ • Financial TS (FA or Time Series Prediction) • RNN, SVR, MLP, RBF Net, + SOM/LVQ Computational Intelligence
FUZZY MODEL STRUCTURE Computational Intelligence
FUZZY MODEL STRUCTURE Computational Intelligence
NN MODEL PARAMETERS • MLP • Input Weights • Output Weights • Neuron model • RNN • Input Weights • Output Weights • Recurrent Weights • Neuron model Computational Intelligence
NN MODEL PARAMETERS Computational Intelligence
NN MODEL PARAMETERS Computational Intelligence
NN MODEL PARAMETERS Computational Intelligence
FUZZY MODEL PARAMETERS Computational Intelligence
PARAMETRIC ESTIMATION Computational Intelligence
PARAMETRIC ESTIMATION Gradient Descent Computational Intelligence
PARAMERTIC ESTIMATIONGenetic Algorithm Computational Intelligence
PARAMERTIC ESTIMATIONGenetic Algorithm Computational Intelligence
PARAMERTIC ESTIMATIONGenetic Algorithm Computational Intelligence
DISCUSSIONS • CI is not the only method (or structure) to solve a problem. • Even it can solve, its performance might not be better than other methods. • Should compare with other well-known or existing methods Computational Intelligence
DISCUSSIONS • SCM Problem • LP, LIP, NLP • Lagrangian Relaxation • Cutting Plane • CPLEX • Function Approximation • Polynomial Series • Trigonometric Series • B-Spline Computational Intelligence
CONCLUSIONS • IF • The problem to be solved has been well formulated • The structure has been selected • The objective function to evaluation the goodness of a parametric vector has been defined • THEN • Every problem is just an optimization problem Computational Intelligence
JOHN SUM (pfsum@nchu.edu.tw) • Taiwan HK-Chinese, PhD (98) and MPhil (95) from CUHK, BEng (92) from PolyU HK. • Taught in HK Baptist University (98-00), OUHK (00) and PolyU HK (00-04), Chung Shan Medical University (05-07) • Adj. Associate Prof., Institute of Software, CAS Beijing (99-02) • Short visit: CityU HK, Griffith University in Australia, FAU, Boca Raton FL US, CAS in Beijing, Ching Mai University in Thailand. • Assist. Prof., IEC (07-09), Asso. Prof., ITM (09-) NCHU Taiwan • 2000 Marquis Who's Who in the World. • Senior Member of IEEE, CI Society, SMC Society (05-) • GB Member, Asia Pacific Neural Network Assembly (09-) • Associate Editor of the IJCA (05-09) • Research Interests include NN, FS, SEM, EC, TM Computational Intelligence