Module 3 - Lecture 08 - Fuzzy Systems Flashcards
Fuzzy systems
What are some advantages of fuzzy modelling?
HFPLIS
- Models based on human approximate reasoning
Models are: - faster
- good in practice (Good performance)
- linguistic
- interpretable (no black boxes)
- simpler
Fuzzy systems
What is a rule base?
A collection of fuzzy rules
Fuzzy systems
What do you call the collection of fuzzy rules in a fuzzy inference system?
A rule base
Fuzzy systems
What is the basic structure of a fuzzy inference system? (RDI)
- Rule base
- Database of linguistic values for the fuzzy rules
- Fuzzy reasoning engine (inference engine)
Fuzzy systems
What are the 3 steps in a FIS (Fuzzy inference system)? (FID)
- Fuzzification
- Fuzzy Inference
- Defuzzification
Fuzzy systems
What input format does a FIS take?
Either crisp values or fuzzy values.
Fuzzy systems
What is a crisp value?
Traditional values, data without MFs.
Fuzzy systems
What do you call an input/output value that’s not fuzzy?
Crisp
Fuzzy systems
What is FIS short for?
Fuzzy inference system
Fuzzy systems
What input types can the Mamdani system take?
Either fuzzy or crisp.
Fuzzy systems
What do you need to do if the input is crisp?
Fuzzification of the input.
Fuzzy systems
What is the basic FIS?
Mamdani type.
Fuzzy systems
What’s a synonym for the Mamdani FIS type?
Basic FIS.
Fuzzy systems
What does defuzzification do?
It transforms fuzzy outputs to crisp values.
Fuzzy systems
In a Mamdani FIS, what T-norm is used?
T-norm operator: min / algebra product
Fuzzy systems
In a Mamdani FIS, what S-norm is used?
S-norm operator: max / sum
Fuzzy systems
In a Mamdani FIS, what is the Fuzzy implication? (What functions)
Fuzzy implication: Sum-product / max-min composition
Fuzzy systems
How do you fuzzify the input value of 70 (x) in the image?
Read the values y = f(x) fro the graph and put them into a vector.
Fuzzy systems
In the attached image, where are the T-norm and S-norm, respectively?
See image
Fuzzy systems
What is the “centre of gravity” method an example of?
A defuzzification method.
Fuzzy systems
What is the formula for the “centre of gravity” method?
See image.
Fuzzy systems
What is the formula for the “bisector of area” method?
See image
Fuzzy systems
What is the formula for the “mean of maximum” method?
See image
Fuzzy systems
What is the formula for calculating z in Sugeno type?
If x is A and y is B, then z = f (x, y)
Fuzzy systems
In a Sugeno type FIS, we have If x is A and y is B, then z = f (x, y).
What are A and B called?
The antecedents
Fuzzy systems
In a Sugeno type FIS, we have If x is A and y is B, then z = f (x, y).
Where is the antecedent(s)?
A and B are antecedents.
Fuzzy systems
In a Sugeno type FIS, we have If x is A and y is B, then z = f (x, y).
What is z = f (x, y) called?
The consequent.
Fuzzy systems
In a Sugeno type FIS, we have If x is A and y is B, then z = f (x, y).
Where is the consequent(s)?
z = f (x, y) is the consequent.
Fuzzy systems
In a Sugeno-type model with z = f(x, y), what is the function f(x, y)?
Usually, a polynomial of x and y.
E.g:
- Zero-order: z = f(x, y) = 3
- First-order: z = f(x, y) = 3x + 2y +3
Fuzzy systems
In this rule example, what is the consequent and what is the antecedent?
If height is tall, then weight is fairly heavy.
Antecedent: If height is tall
Consequent: then weight is fairly heavy.
Fuzzy systems
What do you use to build a FIS?
Data or knowledge/experience.
Fuzzy systems
Can fuzzy systems be used for regression?
Yes.
Fuzzy systems
Can fuzzy systems be used for clustering?
Yes.
Fuzzy systems
How do you check how good a fuzzy system is?
Use error metrics like RMSE.
Fuzzy systems
What is a neuro-fuzzy model?
A fuzzy model tuned using algorithms of NNs.
Fuzzy systems
In a neuro-fuzzy system, what is tuned by the NN methods?
Locations and/or shapes of the membership functions.
Fuzzy systems
What is ANFIS short for?
Adaptive Network-based Fuzzy Inference System
Fuzzy systems
What is FCM short for?
Fuzzy Cognitive Maps
Fuzzy systems
Who is behind FCM (Fuzzy Cognitive Maps)?
Kosko
Fuzzy systems
What is Kosko known for?
FCM (Fuzzy Cognitive Maps)
Fuzzy systems
What are FCMs?
FCMs are fuzzy graphs with possible feedback
What’s the difference between Mamdani-type and Sugeno-type FIS?
Mamdani has fuzzy outputs, and Sugeno uses a polynomial evaluation for outputs.
Mamdani: If pressure is high, then volume is small
Sugeno: If speed is medium, then resistance = 5*speed
