Artificial Intelligence and Expert Systems

estonianmelonAI and Robotics

Oct 24, 2013 (4 years and 14 days ago)

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Artificial Intelligence and Expert Systems





An Overview of

Artificial Intelligence

Artificial Intelligence

in Perspective



Artificial intelligence (AI)



Computers with the ability to mimic or duplicate the functions of the
human brain




Artificial intelligence system



People, procedures, hardware, software, data, and knowledge
needed to develop computer systems and machines that
demonstrate characteristics of intelligence

Characteristics of

Intelligent Behavior



Learn from experience




Handle complex situations




Solve problems when important information is missing




Determine what is important

Characteristics of

Intelligent Behavior



React quickly and correctly to a new situation



Understand visual images



Proces
s and manipulate symbols



Be creative and imaginative



Use heuristics

Natural vs. Artificial Intelligence



Since the term
artificial intelligence

was defined in the 1950s,
experts have disagreed about the difference between natural
and artificial lif
e.




A driving force behind AI research is an attempt to understand
how humans actually reason and think.

Major Branches of

Artificial Intelligence



Expert systems



Robotics



Vision systems



Natural language processing



Learning systems



Neu
ral network

Major Branches of

Artificial Intelligence



Expert systems



Hardware and software that stores knowledge and makes inferences,
similar to a human expert




Robotics



Mechanical or computer devices that perform tasks requir
ing a high
degree of precision or repetitive hazardous tasks

Major Branches of

Artificial Intelligence



Vision systems



Hardware and software that permit computers to capture, store, and
manipulate visual images and pictures almost as precisely as hum
an
experts



Natural language processing



Hardware and software that allow computers to understand and react
to statements and commands made in a human (natural) language

Major Branches of

Artificial Intelligence



Learning systems



A combination of software and hardware that allows the computer to
change how it functions or reacts to situations based on feedback it
receives




Neural network



A computer system that can act like or simulate the functioning of a
human brain

An Overv
iew of

Expert Systems

Characteristics of

Expert Systems



Explain their reasoning or suggested decisions



Display “intelligent” behavior



Draw conclusions from complex relationships



Provide portable knowledge



Deal with uncertainty

Limiting Characteristics of Expert Systems



Not widely used or tested



Difficult to use



Limited to relatively narrow problems



Cannot readily deal with “mixed” knowledge



Possibility of error


Limiting Characteristics of Expert Systems



Cannot refine own knowledge base




Difficult to maintain




May have high development costs




Raise legal and ethical concerns

Capabilities of Expert Systems



Strategic goal setting



Planning



Design



Decision
-
making



Quality control and mon
itoring



Diagnosis

Factors that May Merit Use

of an Expert System



Provide a high potential payoff or significantly reduced
downside risk



Capture and preserve irreplaceable human expertise



Provide expertise needed at a number of locations at the same
time or in a hostile environment that is dangerous to human
health

Factors that May Merit Use

of an Expert System



Provide expertise that is expensive or rare



Develop a solution faster tha
n human experts can



Provide expertise needed for training and development to share
the wisdom of human experts with a large number of people

Components of

Expert Systems

The Knowledge Base



Stores all relevant information, data, rules, cases, and
rel
ationships




If
-
then statements



Rules that suggest certain conclusions




Purpose: To hold relevant facts and information for the expert
system

The Knowledge Base



Assembling human experts



One of the challenges in developing a knowledge base




Use of fuzzy logic



A specialty research area in computer science that allows shades of
gray, or “fuzzy sets”

The Knowledge Base



Use of rules



A conditional statement that links given conditions to actions or
outcomes



Use of cases



Involves finding cases stored in the knowledge base that are similar
to the problem or situation at hand and modifying the solutions to the
cases to fit the current problem or situation

The Inference Engine



Seeks information and relationships from the k
nowledge base
and provides answers, predictions, and suggestions




Backward chaining



Starts with conclusions and works backward to the supporting facts

The Inference Engine



Forward chaining



Starts with the facts and works to a conclusion



Reaches conclusions and yields more information with fewer queries
to the user than backward chaining, but requires more processing
and a greater degree of sophistication

The Explanation Facility



Allows users to understand how the system arrived at cert
ain
conclusions

The Knowledge

Acquisition Facility



Provides a convenient, efficient means for capturing and storing all
components of the knowledge base



[Figure 11.9]

The User Interface



Software employed for designing, creating, updating, and using
expert systems




Purpose: To make development and use of an expert system
easier for users and decision makers

Expert Systems Development

The Development Process

Participants in Developing

and Using Expert Systems

Participants in Developing

and Using Expert Systems



Domain



An area of knowledge




Domain expert



The individual or group who has the expertise or knowledge one is
trying to capture in the expert system

Participants in Developing

and Using Expert Systems



Knowledge engineer



An individual who has training and/or expertise in the design,
implementation, and maintenance of an expert system




Knowledge user



The individual or group who uses and bene
fits from the expert system

Expert Systems Development Tools and
Techniques



Expert systems shells and products



A collection of software packages and tools used to design, develop, implement,
and maintain expert systems

Advantages of Expert Systems Shells and
Products



Easy to develop and modify



Use of satisficing



Use of heuristics



Development by knowledge engineers and users

Expert Systems

Development Alternatives



In
-
house development from scratch



In
-
ho
use development from a shell



Off
-
the
-
shelf purchase: use of existing packages

Applications of Expert Systems and Artificial
Intelligence

Applications of ES and AI



Information management and retrieval



Embedded in products



Plant layout



Hospitals and medical facilities



Help desks and assistance



Employee performance evaluation



Loan analysis

Applications of ES and AI



Virus detection



Repair and maintenance



Shipping



Marketing



Integration with other systems in an organi
zation through a
common database

Information Systems Principles



The overall purpose of artificial intelligence applications in
business is to help the organization achieve its goals.



The ability to create machines that can reason will be possible
onl
y once we truly understand our own processing for doing so.

Information Systems Principles



Sophisticated expert systems can be difficult, expensive, and
time
-
consuming to develop. Make sure that the potential
benefits are worth the effort and that various expert system
characteristics are balanced in terms of cost, control, and
complexity.

Infor
mation Systems Principles



When human experts disagree on important points, it can be
difficult for expert system developers to determine which rules
and relationships to place in the knowledge base.

Information Systems Principles



Specifying the requi
rements for an expert system begins with
identifying the system's objectives and its potential use.

End of Chapter 11