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1、Lecture 1,Introduction to knowledge-base intelligent systems,Intelligent machines, or what machines can do The history of artificial intelligence or from the “Dark Ages” to knowledge-based systems Summary,Intelligent machines, or what machines can do,Philosophers have been trying for over 2000 years
2、 to understand and resolve two Big Questions of the Universe: How does a human mind work, and Can non-humans have minds? These questions are still unanswered. Intelligence is the ability to understand and learn things. 2 Intelligence is the ability to think and understand instead of doing things by
3、instinct or automatically. (Essential English Dictionary, Collins, London, 1990),In order to think, someone or something has to have a brain, or an organ that enables someone or something to learn and understand things, to solve problems and to make decisions. So we can define intelligence as the ab
4、ility to learn and understand, to solve problems and to make decisions. The goal of artificial intelligence (AI) as a science is to make machines do things that would require intelligence if done by humans. Therefore, the answer to the question Can Machines Think? was vitally important to the discip
5、line. The answer is not a simple “Yes” or “No”.,Some people are smarter in some ways than others. Sometimes we make very intelligent decisions but sometimes we also make very silly mistakes. Some of us deal with complex mathematical and engineering problems but are moronic in philosophy and history.
6、 Some people are good at making money, while others are better at spending it. As humans, we all have the ability to learn and understand, to solve problems and to make decisions; however, our abilities are not equal and lie in different areas. Therefore, we should expect that if machines can think,
7、 some of them might be smarter than others in some ways.,One of the most significant papers on machine intelligence, “Computing Machinery and Intelligence”, was written by the British mathematician Alan Turing over fifty years ago . However, it still stands up well under the test of time, and the Tu
8、rings approach remains universal. He asked: Is there thought without experience? Is there mind without communication? Is there language without living? Is there intelligence without life? All these questions, as you can see, are just variations on the fundamental question of artificial intelligence,
9、 Can machines think?,Turing did not provide definitions of machines and thinking, he just avoided semantic arguments by inventing a game, the Turing Imitation Game. The imitation game originally included two phases. In the first phase, the interrogator, a man and a woman are each placed in separate
10、rooms. The interrogators objective is to work out who is the man and who is the woman by questioning them. The man should attempt to deceive the interrogator that he is the woman, while the woman has to convince the interrogator that she is the woman.,Turing Imitation Game: Phase 1,Turing Imitation
11、Game: Phase 2,In the second phase of the game, the man is replaced by a computer programmed to deceive the interrogator as the man did. It would even be programmed to make mistakes and provide fuzzy answers in the way a human would. If the computer can fool the interrogator as often as the man did,
12、we may say this computer has passed the intelligent behaviour test.,Turing Imitation Game: Phase 2,The Turing test has two remarkable qualities that make it really universal. By maintaining communication between the human and the machine via terminals, the test gives us an objective standard view on
13、 intelligence. The test itself is quite independent from the details of the experiment. It can be conducted as a two-phase game, or even as a single-phase game when the interrogator needs to choose between the human and the machine from the beginning of the test.,Turing believed that by the end of t
14、he 20th century it would be possible to program a digital computer to play the imitation game. Although modern computers still cannot pass the Turing test, it provides a basis for the verification and validation of knowledge-based systems. A program thought intelligent in some narrow area of experti
15、se is evaluated by comparing its performance with the performance of a human expert. To build an intelligent computer system, we have to capture, organise and use human expert knowledge in some narrow area of expertise.,The history of artificial intelligence,The first work recognised in the field of
16、 AI was presented by Warren McCulloch and Walter Pitts in 1943. They proposed a model of an artificial neural network and demonstrated that simple network structures could learn. McCulloch, the second “founding father” of AI after Alan Turing, had created the corner stone of neural computing and artificial neural networks (ANN).,The birth of artificial intelligence (1943 1956),The third founder of AI was John von Neumann, the brilliant Hungarian-born mathematician. In 1930, he joined the Prince
