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Artificial Intelligence: AI

an introduction

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Contents

 

Definition

An attempt to model aspects of human thought on computers.

It is also sometimes defined as trying to solve by computer any problem that a human can solve faster.  (1)

 

Natural Language Processing Machines

Language is what sets us apart from the other members of the animal kingdom. Challenges of getting computers to understand human language:

Vocabulary, rules of grammar, syntax complex and changeable. Words can be combined in many ways
Meaning nuance. grammatically correct vs meaningful
Ambiguity metaphor, sarcasm, irony, cultural context

 

ELIZA by Joseph Weizenbaum

Natural language processing machine. Joseph Weizenbaum invented ELIZA more or less as an intellectual exercise to show that natural language processing could be done. ELIZA is an automated psychoanalysis program based on the psychoanalytic principle of repeating what the patient says and drawing introspection out of the patient without adding content from the analyst. Weizenbaum believed a computer program shouldn't be used as a substitute for a human interpersonal respect, understanding, and love. He rejected its use on ethical grounds. See the views on ELIZA: The Machine that Changed the World.

SHRDLU

Pioneering natural language processing system. Could manipulate blocks based on a set of instructions and was programmed to ask questions for clarification of commands.

CYC, (pronounced "psych") by Doug Lenat.

Common Sense-Lenat, "Cyc" project, University of Texas, Austin - Cyc is a very large, multi-contextual knowledge base and inference engine developed by Cycorp, Inc., at Austin, Texas. The goal of the Cyc project is to construct a foundation of basic "common sense" knowledge base of terms, rules, and relations that will enable a variety of knowledge-intensive products and services. Cyc is intended to provide a "deep" layer of understanding that can be used by other programs to make them more flexible. Cyc has provided the foundation for ground-breaking pilot applications in database browsing and integration, captioned image retrieval, and natural language processing. Demonstration of Cyc's "intelligence":

Cyc ... demonstrated it couldn't be fooled into blaming a terrorist act on a suspect who, it had been previously informed, had died.

``He couldn't have done it,'' Cyc responded ``Dead people can't commit terrorist acts.''

references:

Computer News Daily. From Tod Ackerman's article c.1997,
Houston Chronicle. Retrieved WWW 4/15/99 (http://computernewsdaily.com/132_051297_100008_32235.html)
New Scientist http://www.newscientist.com/channel/info-tech/mg18624961.700

 

ALICE by Richard Wallace

(Artificial Linguistic Internet Computer Entity - 1995) is developed by Richard Wallace. ALLICE is the kernel of many seemingly intelligent Chatbots. One of the occurences can be found in Intellibuddy. You can find other versions of ALICE all over the web; the software is free.

 

Artificial Life

computer organisms that reproduce and adapt to their environment, mimicking the natural selection process which occurs with biological organisms.

 

Case Based Reasoning

CBR views reasoning as a process of remembering one or a small set of concrete instances or cases and basing decisions on comparisons between the new and old situation. The problem can then be solved by using the knowledge based on the earlier situation and adapting it.

The steps of CBR generally involve:
-- Retrieve the most similar case
-- Reuse the information in the retrieved case
-- Revise or adapt the case to solve the current problem
-- Retain the solved problem as another case (to be used to help solve another problem).

A case may not be entirely suitable for a new problem and must be adapted.

Examples of CASE systems - Cyrus, HYPO, CASEY.
See Case Based Reasoning on the Web

 

Computer Vision

Pattern Recognition

pattern recognition using cameras for eyes, microphones for ears

Optical Character Recognition (OCR)

Some examples of computer-vision applications:

- Satellite photo interpretation
- Facial characteristics detection
- Digital searching of videos, based on content
- Obstacle detection systems for aircraft navigation
- Automatic analysis of multi-dimensional radiological images
- Machine vision grading of quality of produce (apples, etc).
- Shape recognition and analysis of machined parts

See:
Carnegie Mellon U. Vision and Autonomous Systems Center
Computer vision online demos
Carnegie-Mellon Computer Science Computer Vision Home Page
Computer Vision Handbook, by Dr. Margaret Fleck

 

Fuzzy Logic

Fuzzy logic is a superset of conventional (Boolean) logic that has been extended to handle the concept of partial truth - truth values between "completely true" and "completely false". Dr. Lotfi Zadeh, Professor Emeritus at Berkeley, father of "Fuzzy Logic" , introduced the theory in the 1960's. Interview with Zadeh

 

Games

* Deep Blue Chess game

ACM sponsored match between World Chess Champion, Gary Kasparov and "Deep Blue" chess program. Deep blue won the first game.

* Samuel's Checker's Player -

Arthur Samuel's Checkers player experiments (1959 and 1967) were the earliest success stories in machine learning . His machine evaluated board positions in the game of checkers

* Gerald Tesauro - TD Gammon

Gerald Tesauro was able to play his programs in a significant number of games against world-class human players. His TD-Gammon 3.0 appears to be at, or very near, the playing strength of the best human players in the world. TD-Gammon learned to play certain opening positions differently than was the convention among the best human players. Based on TD-Gammon's success and further analysis, the best human players now play these positions as TD-Gammon did.

* Edward Tufte

Visual Explanations : Images and Quantities, Evidence and Narrative - book explores how visual evidence influences computer interfaces, design strategies, and how information is transferred and represented, including the arts and science.

Genetic Algorithms

Uses the principles of Charles Darwin's natural selection :

Natural selection - Some traits in a species cause a member of that species to be better suited to its environment than some other traits. The members of the species with the characteristics that give it the strongest possibility to survive, pass those traits on to offspring. The species with the stronger characteristics mate and pass the traits on in the process called natural selection.
Crossover is the term for natural selectionin genetic algorithms. In crossover, natural selection is accomplished when the genetic algorithm:
1. Selects the set of best possible solutions to a problem
2. Selects the best candidates among the set of best possible solutions.
3. Selects pairs of solutions and the best parts of each solution to create a new solution - called crossover.

 

Knowledge Engineering/Expert Systems

What are Expert Systems?
Conventional programming languages, such as FORTRAN and C, are designed to manipulate data, such as numbers. Humans, on the other hand, can solve complex problems using very abstract, symbolic approaches, not well suited for conventional programming languages. Abstract information can be modeled in conventional programming languages, but significant effort is needed to transform the information to a usable format which deals with high levels of abstraction, more closely resembling human logic. The programs which emulate human logic are called expert systems.

The expert system tool provides a mechanism, called the inference engine, which automatically matches facts against patterns and determines which rules are applicable. The if portion of a rule applies to the situation (if "such and such" happens or changes"). The then portion of a rule is the set of actions to be executed when the rule is applicable. The inference engine then selects another rule and executes its actions. This process continues until no applicable rules remain.

 

Neural Networks

Artificial Intelligence systems that attempt to duplicate the physical functioning of the human brain by using a biological model of intelligence.

Three (3) parts of a neural network:

- input layer corresponding to the 5 human senses: sight, hearing, touch, smell, taste
- processing layer (hidden) corresponding to neurons in the brain
- output layer corresponding to parts of the body that act on signals from the brain (muscles, etc.)


Input layer ----------------- > Processing layer ---------- > Output layer ---------------- >
(Hidden layer)
cameras, microphones, Computers plus printers, screens, robot arms,
data gathering equipment programs and functions chemical dispensers

NNs "learn" from examples and exhibit some capability for generalization beyond the specific example. Knowledge is acquired by the network through a learning process.

Where can neural network systems help?

- where we can't formulate an algorithmic solution.
- where we can get lots of examples of the behavior we require.
- where we need to pick out the structure from existing data.

Real human brains, however, are orders of magnitude more complex than any artificial neural network so far developed.

Existing computer "logic is not good at interacting with "noisy" data, and adapting to unexpected or unusual circumstances.

See: Genetics Algorithms Archives
Hitchhiker's Guide to Evolutionary Computation

Herbert. A. Simon, Allen Newell & J.C. Shaw: In 1957 devised a logic theory machine (first proof by machine) the General Problem Solver (GPS). The method for testing the theory involved developing a computer simulation and then comparing the results of the simulation with human behavior in a given task.

Simon believes that brain activities, as well as computer processing activities can be explained in terms of information processing. Creativity can be automated, he believes, by having the computer do selective searches, then recognize cues that index knowledge in given situations. For example, he says, his his chess playing computer can separate the important moves from the unimportant ones, for a given chess configuration, and even know when the opposing player makes an error.

 

The players

 

Alan Turing  - -- 1912-1954.  Turing is perhaps best remembered for the concepts of the Turing Test for Artificial Intelligence, the "acid test" of true artificial intelligence, and the Turing Machine, an abstract model for modeling computer operations. He said "a machine has artificial intelligence when there is no discernible difference between the conversation generated by the  machine and that of an intelligent person." 

Marvin Minsky-  has made many contributions to AI, cognitive psychology, mathematics, computational linguistics, robotics, and optics.  In 1951 he built the SNARC, the first neural network simulator. His other inventions include mechanical hands and other robotic devices. His recent work is to develop machines with the capacity for commonsense reasoning. 

John Searle - Chinese Room theory - Searle, a philosopher, proposed a thought experiment outlining why computers can't think. He considers the following thought-experiment. Suppose that a person were given a set of purely formal rules for manipulating Chinese symbols. The rules are a complete set of instructions that might be implemented on a computer designed to engage in grammatically correct conversations in Chinese. The person in the room, however, does not understand Chinese, yet can produce the correct symbols to give the correct response.

Hubert Dreyfuss - Dreyfuss, a philosopher, says that computer games do nothing more than calculate which moves are the best. Wrote What Computers Still Can't Do : A Critique of Artificial Reason

(3)

Noam Chomsky - Linguist, scholar and prominent political dissident in the United States. Three Models of Language (transformational grammar; formal precision)

Herbert A. Simon and AI
Simon, H.A. Interview. (1994, June). Omni Magazine, 16(9), 70-89.

 

Chronology

8

One of the first stories of A.I., as a story is written of how a man falls in love with a statue he has created that has come to life.

 

1927

Fritz Lang's "Metropolis" film is created, based on an android built in the form of its creator's wife. Commonly known as the precursor to Star War's C-3PO.

 

1936

Alan Turing publishes paper entitled, "On Computable Numbers," which basically describes the parameters of a basic modern computer.

 

1941

Science fiction writer Isaac Asimov develops his "Three Laws of Robotics," which is 1) A robot may not injure a human being or allow a human to be injured 2) Must obey the commands of the human and 3) A robot must protect its own very existence.

 

1943

Warren McCulloch and Walter Pitts publish "A logical calculus of the ideas immanent in nourvous activity" to describe neural networks that can learn.

 

1950

Claude Shannon publishes an analysis of chess playing as a research process.

Alan Turing proposes the Turing Test, to decide whether a computer is exhibiting intelligent behaviour.

 

1956

The acronym AI - artificial intelligence - is coined by John McCarty at a conference at Darthmout College, New Hampshire.

Demonstration of the first AI program, called Logic Theorist, created by Allen Newell, Cliff Shaw and Herbert Simon at the Carnegie Institute of Technology, now Granegie Mellon University.

Stanislaw Ulam develops "Maniac I", the first chess program to beat a human player, at the los Alamos National Laboratory.

 

 

1965

Herbert Simon predicts that "by 1985 machines will be capable of doing any work a man can do"

1966

Joseph Weizenbaum, a computer scientist at the Massachusetts Institute of Technology, develops Eliza, the world's first chatbot

1969

Shakey, a robot built by the Stanford Research Institute in California, combines locomotion, perception and problem solving

1975

John Holland describes genetic algorithms in his book Adaptation in Natural and Artificial Systems125

1979

A computer-controlled autonomous vehicle called the Stanford Cart, built by Hans Moravec at Stanford University, successfully negotiates a chair-filled room


1982

The Japanese Fifth Generation Computer project to develop massively parallel computers and a new artificial intelligence is born

Mid-1980s

Neural networks become the new fashion in AI research

1989

Popular computer game "Sim City" is created in which players can control virtual people known as "Sims."

 

1991

The battle of the super robots. "Terminator 2" depicts good android against bad in simulation of a future decimated by nuclear war.

 

1995

ALICE

(Artificial Linguistic Internet Computer Entity - 1995) is developed by Richard Wallace. ALLICE is the kernel of many seemingly intelligent Chatbots. One of the occurences can be found in Intellibuddy. You can find other versions of ALICE all over the web; the software is free.

 

1997

The Mars "Pathfinder" is able to walk upon Mars, sending back to Earth images and scientific observations of the red planet.

The Deep Blue chess program beats the then world chess champion, Garry Kasparov

Microsoft's Office Assistant, part of Office 97, uses AI to offer customised help

1999

Remote Agent, an AI system, is given primary control of NASA's Deep Space 1 spacecraft for two days, 100 million kilometres from Earth

2001

The Global Hawk uncrewed aircraft uses an AI navigation system to guide it on a 13,000-kilometre journey from California to Australia

2004

In the DARPA Grand Challenge to build an intelligent vehicle that can navigate a 229-kilometre course in the Mojave desert, all the entrants fail to complete the course

2005

Cyc to go online

 

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Organizations and important developers

 

 

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Books on AI

an annotated bibliography

 

 

 

Go Backindexopen main page Last Update 23 April, 2005 For suggestions please mail the editors 

 

Footnotes & References