Artificial
Intelligence 111
To put a
context around this technology the term embraces a fundamental change in
computer programming. To date computer programming has been based around a
detailed understanding of the process to be computerised and a step by step
translation into instructions for the computer. The general word for this is
that an algorithm is constructed. This is a fancy way of saying that the
problem is precisely understood and a solution can be developed.
An example
would be the calculation on the interest paid at 2.5% on a principal of £1500
over 2years and 7 months. This is a precise calculation which can only give one
answer and the way of calculating it is also known precisely.
Back when I was
a student this was contrasted with heuristics where the precise solution is
unknown but human intuition based perhaps on analogy can lead towards a
solution. Heuristics can lead to rules, by which are really meant
generalisations. Heuristics often doesn’t give one precisely correct answer but
rather a series of options depending on the precise nature of the question
An example
might be a controller of traffic lights at a multi way junction. If the lights
can detect vehicles then one might say release traffic until all vehicles have
passed on the major route, Conversely only stop the major route in both
directions if a vehicle approaches on a minor route. Then suppose we want the
lights to behave differently at rush hour. Different rules might be say let the
first 50 vehicles pass on the major route before switching. So far an algorithm
could be applied but then suppose some more general conditions were applied
such as requirement for the lights to perform in the most optimal manner
reducing vehicle delays to a minimum. Then a precise solution would be unlikely
and heuristics would be needed ( Incidentally I would like to see this no doubt
hideously expensive solution used )
Artificial
intelligence is fundamentally different. It is based upon the study of the
brain and how it works. Essentially the brain consists of neurons connected to
others in what can be thought of as layers. When we learn the pathway from
neuron to neuron is strengthened for a right answer and not strengthened if the
answer is wrong. Artificial intelligence uses a brain like structure often
called a neural net. This network can be many layers deep. As it stands the
network knows nothing but is trained by giving examples. Suppose a neural net
is asked to say when given a picture whether it is a cat or a dog. Many
thousands of pictures are presented and the trainer tells the net whether it is
a cat or a dog. If a dog then connections are reinforced in one way, if a cat
then reinforced in another.
Subsequently if
presented with an unknown image the net can respond either down the dog route
or the cat route depending on where the neuron connections have been reinforced.
The power of AI is that the network can interpolate, ie observing that the
image is ( say ) dog like but not cat like. Generally AI cannot extrapolate
very well.
It can be seen
there are two fundamental steps. Firstly setting up the neural net and second
training it on external data of known type. This process is totally different
from trying give instructions to the computer which enables it to differentiate between cats and dogs.
This a grossly
oversimplified description of AI but the principle is always the same. AI needs
a lot of training data. This explains why such data is so valuable. An AI
system may be able to see patterns in data which a human cannot. On the other
hand an AI has no common sense. Even a well trained AI can look at a dog and
see something entirely different.
One intriguing
way in which an AI system can be used is to unleash it on a system and just
tell it when its right or wrong. The AI can slowly learn the system and may
even spot hitherto unknown possibilities. AI’s are particularly good at games
which have precise rules but give rise to very many possibilities like chess. A
good AI can beat a chess master.
One heavily
publicised possibility is self driving vehicles. As this is written there are
prototypes on roads. Often this is within particular boundaries such as the
City of Phoenix in the USA. Such prototypes usually have manual supervision.
Tesla cars have an extremely advanced version which has the objective of only
using camera “eyes” and capable of driving anywhere. Vehicles have been made
available in beta test to the public but are not generally available. The self
driving AI continues to be tweaked
It is important
to realise that AI’s are not intelligent in the way a human is. Humans bring a
lot of general learning to tasks and generally avoid the kind of silly mistakes
that an AI can make. For example if a human looks at an animal picture with the
name tag “Tiiddles” round its neck then the human can probably guess the animal
is a cat without any more information from the picture. This is the kind of
intelligence which an AI would find difficult.
Some eminent
technologists are concerned about the future. They worry that an AI could invent
a better version of itself and that this could escalate into a super
intelligence far outstripping humans.
One doesn’t go
very far without coming across the “Three laws of robotics” Conceived in
science fiction by the eminent writer Isaac Asimov they are sometimes seen as
the basis of a “thought experiment” when AI has advanced far enough.
The laws are-
1 A robot may
not injure a human being or, through inaction, allow a human being to come to
harm.
2 A robot must
obey instructions given to it by a human being unless this conflicts with First
Law
3 A robot must
protect its own existence unless this conflicts with First or Second Law.
Although a
fictional device these laws are very widely quoted. There have been various
efforts to pronounce in advance ethical principles for robotics. Incidentally
it should be noted these are for self mobile robots while all existing examples
of AI are static “brains”
An immense
amount of money and brain power are being invested in AI and the field is
moving fast. After previous false dawns it does seem as though exciting tools
are on the verge of development. There has been some over excited speculation
of mass unemployment. All previous technological developments tell us this is
highly unlikely; more leisure hopefully, but also different jobs made possible
by AI tools.
No comments:
Post a Comment