ARTIFICIAL INTELLIGENCE——人工智能(英文)

ARTIFICIAL INTELLIGENCE——人工智能

1 Artificial intelligence (AI) is, in theory, the ability of an artificial mechanism to

demonstrate some form of intelligent behavior equivalent to the behaviors observed in

intelligent living organisms. Artificial intelligence is also the name of the field of

science and technology in which artificial mechanisms that exhibit behavior

resembling intelligence are developed and studied.

2 The term AI itself, and the phenomena actually observed, invite --- indeed

demand --- philosophical speculation about what in fact constitutes the mind or

intelligence. These kinds of questions can be considered separately, however, from a

description of the various endeavors to construct increasingly sophisticated

mechanisms that exhibit “intelligence.”

3 Research into all aspects of AI is vigorous. Some concern exists among workers

in the field, however, that both the progress and expectations of AI have been

overstated. AI programs are primitive when compared to the kinds of intuitive

reasoning and induction of which the human brain or even the brains of much less

advanced organisms are capable. AI has indeed shown great promise in the area of

expert systems --- that is, knowledge-based expert programs --- but while these

programs are powerful when answering questions within a specific domain, they are

nevertheless incapable of any type of adaptable, or truly intelligent, reasoning.

4 Examples of AI systems include computer programs that perform such tasks as

medical diagnoses and mineral prospecting. Computers have also been programmed

to display some degree of legal reasoning, speech understanding, vision interpretation,

natural-language processing, problem solving, and learning. Although most of these

systems have proved valuable either as research vehicles or in specific, practical

applications, most of them are also still very far from being perfected.

5 CHARACTERISTICS OF AI: No generally accepted theories have yet emerged

within the field of AI, owing in part to the fact that AI is a very young science. It is

assumed, however, that on the highest level an AI system must receive input from its

environment, determine an action or response, and deliver an output to its

environment. A mechanism for interpreting the input is needed. This need has led to

research in speech understanding, vision, and natural language. The interpretation

must be represented in some form that can be manipulated by the machine.

6 In order to achieve this goal, techniques of knowledge representation are invoked.

The AI interpretation of this, together with knowledge obtained previously, is manipulated within the system

under study by means of some mechanism or

algorithm. The system

thus arrives at

an internal representation of the response or

action. The development of such processes requires techniques of expert reasoning,

common-sense reasoning, problem

solving, planning, signal interpretation, and

learning. Finally, the system must网

construct

an effective response. This

requires techniques of

natural-language

generation.

7 THE FIFTH-GENERATION ATTEMPT: In the 1980s, in an attempt to develop

an expert system on a very large scale, the

Japanese government began building

powerful computers with hardware that made logical inferences in the

computer

language PROLOG. (Following the idea of representing knowledge declaratively, the

logic programming PROLOG had been developed in England and France. PROLOG

is actually an inference engine that searches declared facts and rules to confirm or

deny a hypothesis. A drawback of PROLOG is that it cannot be altered by the

programmer.) The Japanese referred to such machines as “fifth-generation”

computers.

8 By the early 1990s, however, Japan had forsaken this plan and even announced

that they were ready to release its software. Although they did not detail reasons for

their abandonment of the fifth-generation program, U.S scientists faulted their efforts

at AI as being too much in the direction of computer-type logic and too little in the

direction of human thinking processes. The choice of PROLOG was also criticized.

Other nations were by then not developing software in that computer language and

were showing little further enthusiasm for it. Furthermore, the Japanese were not

making much progress in parallel processing, a kind of computer architecture

involving many independent processors working together in parallel—a method

increasingly important in the field of computer science. The Japanese have now

defined a “sixth-generation” goal instead, called the Real World Computing Project,