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www.abdn.ac.uk/sras
Artificial IntelligenceIn the Real World
Computing Science
University of Aberdeen
www.abdn.ac.uk/sras
Artificial IntelligenceIn the Real World
Artificial IntelligenceIn the Movies
www.abdn.ac.uk/sras
Artificial IntelligenceIn the Real World
Artificial IntelligenceIn the Movies
www.abdn.ac.uk/sras
Artificial IntelligenceIn the Real World
Artificial IntelligenceIn the Movies
?
www.abdn.ac.uk/sras
Artificial Intelligence Began in 1956…
• Great expectations…
““Machines will be capable, Machines will be capable,
within twenty years, within twenty years,
of doing any work that a man of doing any work that a man
can do.”can do.”
Herbert Simon, 1965.
www.abdn.ac.uk/sras
““Machines will be capable, Machines will be capable,
within twenty years, within twenty years,
of doing any work that a man can do.”of doing any work that a man can do.”
Herbert Simon, 1965.
What Happened?
www.abdn.ac.uk/sras
• Machines can’t do everything a man can do…• People thought machines could replace humans…
instead they are usually supporting humans
““Machines will be capable, Machines will be capable,
within twenty years, within twenty years,
of doing any work that a man can do.”of doing any work that a man can do.”
Herbert Simon, 1965.
What Happened?
www.abdn.ac.uk/sras
• Machines can’t do everything a man can do…• People thought machines could replace humans…
instead they are usually supporting humans– Healthcare, Science, Government, Business, Military…
““Machines will be capable, Machines will be capable,
within twenty years, within twenty years,
of doing any work that a man can do.”of doing any work that a man can do.”
Herbert Simon, 1965.
What Happened?
www.abdn.ac.uk/sras
• Machines can’t do everything a man can do…• People thought machines could replace humans…
instead they are usually supporting humans– Healthcare, Science, Government, Business, Military…
• Most difficult problems are solved by human+machine– astronomy, nuclear physics, genetics, maths, drug discovery…
““Machines will be capable, Machines will be capable,
within twenty years, within twenty years,
of doing any work that a man can do.”of doing any work that a man can do.”
Herbert Simon, 1965.
What Happened?
www.abdn.ac.uk/sras
Neural Networks
• Neural Networks are a popular Artificial Intelligence technique
• Used in many applications which help humans
• The idea comes from trying to copy the human brain…
www.abdn.ac.uk/sras
Fascinating Brain Facts…• 100,000,000,000 = 1011 neurons -100 000 are irretrievably lost each day!
• Each neuron connects to 10,000 -150,000 others
• Every person on planet make 200 000 phone calls
– same number of connections as in a single human brain in a day
• Grey part folded to fit - would cover surface of office desk
• The gray cells occupy only 5% of our brains
– 95% is taken up by the communication network between them
• About 2x106km of wiring (to the moon and back twice)
• Pulses travel at more than 400 km/h (250 mph)
• 2% of body weight… but consumes 20% of oxygen
• All the time! Even when sleeping
• What about copying neurons in Computers?
www.abdn.ac.uk/sras
Artificial Neural Network (ANN)
• loosely based on biological neuron
• Each unit is simple, but many connected in a complex network
• If enough inputs are received– Neuron gets “excited”
– Passes on a signal, or “fires”
• ANN different to biological:– ANN outputs a single value
– Biological neuron sends out a complex series of spikes
– Biological neurons not fully understoodImage from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer
Associates and WH Freeman
www.abdn.ac.uk/sras
Now play with the flash animation to see how synapses work
http://www.mind.ilstu.edu/curriculum/neurons_intro/flash_summary.php?modGUI=232&compGUI=1828&itemGUI=3160
www.abdn.ac.uk/sras
The Perceptron
add
weight1
output
input1
input2
input3
input4
weight4
(threshold)
weight2
wei
ght 3
www.abdn.ac.uk/sras
The Perceptron
add
weight1
output
input1
input2
input3
input4
weight4
(threshold)
weight2
wei
ght 3
Save Graph and Data
www.abdn.ac.uk/sras
The Perceptron
Note: example from Alison Cawsey
student first last year
male works hard
Lives in halls
First this year
1 Richard 1 1 0 1 0
2 Alan 1 1 1 0 1
3 Alison 0 0 1 0 0
4 Jeff 0 1 0 1 0
5 Gail 1 0 1 1 1
6 Simon 0 1 1 1 0
Save Graph and Data
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.2Threshold
= 0.5
0.2
0.2
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
1 Richard 1 1 0 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.15
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.15
0.2
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
1 Richard 1 1 0 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.15
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.15
0.2
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
2 Alan 1 1 1 0 1
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.2
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
2 Alan 1 1 1 0 1
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.2
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
3 Alison 0 0 1 0 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.2
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
4 Jeff 0 1 0 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.2
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
5 Gail 1 0 1 1 1
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.2
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
6 Simon 0 1 1 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.15
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
6 Simon 0 1 1 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.15
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
1 Richard 1 1 0 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.15
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
2 Alan 1 1 1 0 1
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.15
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
3 Alison 0 0 1 0 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.15
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
4 Jeff 0 1 0 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.2
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.15
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
5 Gail 1 0 1 1 1
www.abdn.ac.uk/sras
The Perceptron
add
0.25
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.15
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
5 Gail 1 0 1 1 1
www.abdn.ac.uk/sras
The Perceptron
add
0.25
_output
First last year _
Male_
_hardworking _
Lives in halls
0.15Threshold
= 0.5
0.15
0.25
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
6 Simon 0 1 1 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.25
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.10
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
6 Simon 0 1 1 1 0
www.abdn.ac.uk/sras
The Perceptron
add
0.25
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.10
0.20
Note: example from Alison Cawsey
Finished
www.abdn.ac.uk/sras
The Perceptron
add
0.25
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.10
0.20
Note: example from Alison Cawsey
FinishedReady to try unseen examples
www.abdn.ac.uk/sras
The Perceptron
add
0.25
_output
First last year _
Male_
_hardworking _
Lives in halls
0.10Threshold
= 0.5
0.10
0.20
Note: example from Alison Cawsey
student First last year male works hard Lives in halls First this year
James 0 1 0 1 ?
www.abdn.ac.uk/sras
The Perceptronadd
0.25
_output
0.10Threshold
= 0.5
0.10
0.20
• Simple perceptron works ok for this example but sometimes will never find weights that fit everything
• In our example:– Important: Getting a first last year, Being hardworking
– Not so important: Male, Living in halls
• Suppose there was an “exclusive or” - – Important: (male) OR (live in halls), but not both
– Can’t capture this relationship
www.abdn.ac.uk/sras
Stock Exchange ExampleCompany Name Company less
than 2 years old
Paid dividend >10% last year
Share price increases in following year
1 Robot Components Ltd. 1 1 0
2 Silicon Devices 1 0 1
3 Bleeding Edge Software
0 0 0
4 Human Interfaces Inc. 1 1 0
5 Data Management Inc. 0 1 1
6 Intelligent Systems 1 1 0
www.abdn.ac.uk/sras
Multilayer Networks
• We saw: perceptron can’t capture relationships among inputs
• Multilayer networks can capture complicated relationships
www.abdn.ac.uk/sras
Stock Exchange Example
Hidden Layer
www.abdn.ac.uk/sras
Neural Net example: ALVINN• Autonomous vehicle controlled by Artificial Neural Network
• Drives up to 70mph on public highways
Note: most images are from the online slides for Tom Mitchell’s book “Machine Learning”
www.abdn.ac.uk/sras
Neural Net example: ALVINN• Autonomous vehicle controlled by Artificial Neural Network
• Drives up to 70mph on public highways
• Note: most images are from the online slides for Tom Mitchell’s book “Machine Learning”
www.abdn.ac.uk/sras
ALVINN
Input is 30x32 pixels= 960 values
1 input pixel
4 hidden units
30 output units
Sharp right
Straight ahead
Sharp left
www.abdn.ac.uk/sras
ALVINN
Input is 30x32 pixels= 960 values
1 input pixel
4 hidden units
30 output units
Sharp right
Straight ahead
Sharp left
Learning means adjusting weight
values
www.abdn.ac.uk/sras
ALVINN
Input is 30x32 pixels= 960 values
1 input pixel
4 hidden units
30 output units
Sharp right
Straight ahead
Sharp left
www.abdn.ac.uk/sras
ALVINN
www.abdn.ac.uk/sras
ALVINN
This shows one hidden node
Input is 30x32 array of pixel values = 960 values Note: no special visual processing
Size/colour corresponds to weight on link
www.abdn.ac.uk/sras
ALVINN
This shows one hidden node
Input is 30x32 array of pixel values = 960 values Note: no special visual processing
Size/colour corresponds to weight on link
Output is array of 30 values This corresponds to steering
instructions E.g. hard left, hard right
www.abdn.ac.uk/sras
• Let’s try a more complicated example with the program…
• In this example we’ll get the program to help us to build the neural network
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)– Robot control - hand-arm-block.mpg
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)– Robot control– ECG pattern – had a heart attack?
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)– Robot control– ECG pattern – had a heart attack?– Application for credit card or mortgage
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)– Robot control– ECG pattern – had a heart attack?– Application for credit card or mortgage– Data Mining on Customers
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical
– Character recognition (typed or handwritten)
– Image recognition (e.g. human faces)
– Robot control
– ECG pattern – had a heart attack?
– Application for credit card or mortgage
– Other types of Data Mining - Science
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)– Robot control– ECG pattern – had a heart attack?– Application for credit card or mortgage– Spam filtering
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical– Character recognition (typed or handwritten)– Image recognition (e.g. human faces)– Robot control– ECG pattern – had a heart attack?– Application for credit card or mortgage– Shape in go
www.abdn.ac.uk/sras
Neural Network Applications• Particularly good for pattern recognition
– Sound recognition – voice, or medical
– Character recognition (typed or handwritten)
– Image recognition (e.g. human faces)
– Robot control
– ECG pattern – had a heart attack?
– Application for credit card or mortgage
– Data Mining on Customers
– Other types of Data Mining
– Spam filtering
– Shape in Go… and many more!
www.abdn.ac.uk/sras
What are Neural Networks Good For?
• When training data is noisy, or inaccurate– E.g. camera or microphone inputs
• Very fast performance once network is trained• Can accept input numbers from sensors directly
– Human doesn’t need to interpret them first
www.abdn.ac.uk/sras
• Need a lot of data – training examples
• Training time could be very long– This is the big problem for large networks
• Network is like a “black box”– A human can’t look inside and understand what has been learnt
– Logical rules would be easier to understand
Disadvantages?