Lecture 04 - Fundamental Problems

8/6/2019 Lecture 04 - Fundamental Problems

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Department of Computing Science, Fall 2010


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Artificially Intelligent Behavior

Problems with Classical Artificial Intelligence

By Erik Billing

Department of Computing Science, Fall 2010


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New Homework on Monday!

Write down one topic/question that you find interestingand that you want me to bring up during Lecture 5. The

topic/question should something from Chapter 4 ofPfeifer and Scheier.

Due May 13, 8.00


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Questions

Why is the Traveling Salesman Problem so popular in AI?

Elaborate the difference between agent simulation andclassical simulation


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Traveling salesman problem

A salesman is about to visit a number of cities

He wants to visit each city at least once

He wants to travel the shortest distance possible

A Classical problem in AI

Because its very hard (NP-hard)

The complexity of a exhaustive search if TSP isO(n!)

I.e., the time it takes to search all

combinations increases exponentially with thenumber of cities (n)


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TSP with Ants

Ants run around

randomly searchingfor food

When they find foodthey leave a phero-

mone trace on theirway back to the nest

The trace makes this route more attractive toother ants, which in turn leave their own tracemaking the route even more attractive

Since ants taking a short route will fetch foodfaster than ants taking a longer route, thetrace of the short route will become stronger


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TSP Comparison

TSP by Search Typical example of

Classical AI

It requires arepresentation of theworld

Sequential

Guarantees an optimalsolution

Clear stopping condition

All or nothing

TSP by Ants Typical agent-based

approach

It could be implementedphysically without arepresentation

Parallel

Solution is emergent(may be suboptimal)

No stopping condition

Robust and fault

tolerant

See articleAnt Colony System on the course page

(under extra readings in the literature list)


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Questions

Give another example of the frame problem


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The frame problem

How to keep a model of the world (arepresentation) up to date?

Essentially, anything can happen at any time

How to sport out the relevant possibilitiesform completely irrelevant ones?

R1 The sleeping dog

Everything has to be made explicit R1D1

Consider everything

R2D1

Sort out relevant consequences to consider


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The frame problem - Solution


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Symbol grounding

In GOFAI, intelligence is the manipulation ofsymbols

Symbols

Are defined within a symbol system

Have relations to other symbols

Refer to an object in the outer world

(referent) There are rules of how these symbols may be

combined

How do we connect the symbol with its referent?


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Symbol grounding

Example:

Four symbols {1, 2, +, 3}

Combine the symbols 1 + 2 Produces the symbol 3

A human will interpret the meaning of the

symbol 3 in relation to the specific problem weare trying to solve


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Symbol grounding

Example

Four symbols {CUP, DRINK FULL, EMPTY}

Combine: CUP FULL DRINK Produces: CUP EMPTY

A human can interpret the meaning of this

example and apply it in a specific situation How do we implement this ability in a robot?


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Symbol grounding

Further problems

How do an agent create new symbols?

How do an agent decide what a symbol shouldrefer to before the relation is there?

Remember, symbols are the mechanism ofintelligence, we cant refer to some othermechanism without breaking the PhysicalSymbol System Hypothesis

How do the agent change the ontology

The ontology is the boundary of what theagent can represent (i.e., know)


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Symbol grounding

GIFAI Conclusion

Humans can dosymbol grounding

so it must be

possible

Embodied Conclusion

Humans can not besymbol processing

systems


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Questions

Do true intelligence require a biologicalsystem?

Central processing is a reason for delays

Can we use more powerful processors?

What about real-time processing?


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More Questions

You showed us in class some agents that behavedaccording to some basic rules. When I saw thegraphics that were simulating a population my

question came up:

All the programmed robots/agents used tomodel and predict financial behaviours (stockexchange market, forex exchange market...)

are based in the same concept of "basic" rulesof the ones we saw in class?


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Questions: Intelligence

If I am not wrong, in class, you said that IQ testscould say pretty much if someone is intelligent.

Which aspects of intelligence does an IQ testmeasure? And how does it measures them?

Are a virus intelligent since it can adapt to itsenvironment and maximize its energy?

Why does some defintions of intelligence includethe influence of and adaption to the enviromentand others do not? How can one argue thatintelligence is independent from environmentaladaption?

Why does creativity have to be related toemotions?


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Questions: Searching

Explain Depth-limited search and in whichsituations its useful

What happens to a search problem on a mapwhen you have modern GPS technology, currenttraffics information on roads and so on?


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Consciousness

that the role of consciousness in mental life isvery small, almost frighteningly so. The aspectsof mental life that require consciousness have

turned out to be a relatively minor fraction of thebusiness of the brain''

I think it seems a bit exaggerated. What doesit mean bye "Mental life"?

The book states that consciousness is somethingwe with certainty only can attribute to humans

Where does this statement come from and is

this really a common belief (especially in thescientific society)?

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Lecture 04 - Fundamental Problems