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A.i & Expert System

Apr 06, 2018

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    ITEC 1010 Information and Organizations

    Chapter 11

    Artificial Intelligence and

    Expert Systems

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    ITEC 1010 Information and Organizations

    Overview of Artificial

    Intelligence (1)Artificial intelligence (AI)

    Computers with the ability to mimic or

    duplicate the functions of the human brain

    Artificial intelligence systems

    The people, procedures, hardware, software,

    data, and knowledge needed to developcomputer systems and machines that

    demonstrate the characteristics of intelligence

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    ITEC 1010 Information and Organizations

    Overview of Artificial

    Intelligence (2) Intelligent behaviour

    Learn from experience

    Apply knowledge acquired from experience

    Handle complex situations Solve problems when important information is missing

    Determine what is important

    React quickly and correctly to a new situation

    Understand visual images Process and manipulate symbols

    Be creative and imaginative

    Use heuristics

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    ITEC 1010 Information and Organizations

    Major Branches of AI (1)

    Perceptive system

    A system that approximates the way a human sees, hears, andfeels objects

    Vision system

    Capture, store, and manipulate visual images and pictures

    Robotics

    Mechanical and computer devices that perform tedious tasks

    with high precision

    Expert system

    Stores knowledge and makes inferences

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    ITEC 1010 Information and Organizations

    Major Branches of AI (2)

    Learning system

    Computer changes how it functions or reacts to situationsbased on feedback

    Natural language processing

    Computers understand and react to statements and commandsmade in a natural language, such as English

    Neural network

    Computer system that can act like or simulate the functioningof the human brain

    Schematic

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    ITEC 1010 Information and Organizations

    Artificial

    intelligence

    Robotics

    Vision

    systems

    Learning

    systems

    Natural language

    processing

    Neural networks

    Expert systems

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    ITEC 1010 Information and Organizations

    Artificial Intelligence (1)

    The branch of computer science concerned with making computers

    behave like humans. The term was coined in 1956 by John McCarthy

    at the Massachusetts Institute of Technology. Artificial intelligenceincludes

    games playing: programming computers to play games such as

    chess and checkers

    expert systems : programming computers to make decisions in real-life

    situations (for example, some expert systems help doctors diagnosediseases based on symptoms)

    natural language : programming computers to understand natural

    human languages

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    ITEC 1010 Information and Organizations

    Artificial Intelligence (2)

    neural networks : Systems that simulate intelligence by attemptingto reproduce the types of physical connections that occur in animalbrains

    robotics : programming computers to see and hear and react toother sensory stimuli

    Currently, no computers exhibit full artificial intelligence (that is, are

    able to simulate human behavior). The greatest advances have

    occurred in the field of games playing. The best computer chessprograms are now capable of beating humans. In May, 1997, an IBM

    super-computer called Deep Blue defeated world chess champion

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    ITEC 1010 Information and Organizations

    Artificial Intelligence (3)

    Gary Kasparov in a chess match.

    In the area of robotics, computers are now widely used in assembly

    plants, but they are capable only of very limited tasks. Robots have

    great difficulty identifying objects based on appearance or feel, and

    they still move and handle objects clumsily.

    Natural-language processing offers the greatest potential rewards

    because it would allow people to interact with computers without

    needing any specialized knowledge. You could simply walk up to a

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    ITEC 1010 Information and Organizations

    Artificial Intelligence (4)

    computer and talk to it. Unfortunately, programming computers to

    understand natural languages has proved to be more difficult than

    originally thought. Some rudimentary translation systems thattranslate from one human language to another are in existence, but

    they are not nearly as good as human translators. There are also

    voice recognition systems that can convert spoken sounds into

    written words, but they do not understand what they are writing;they simply take dictation. Even these systems are quite limited --

    you must speak slowly and distinctly.

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    ITEC 1010 Information and Organizations

    Artificial Intelligence (5)

    In the early 1980s, expert systems were believed to represent the

    future of artificial intelligence and of computers in general. To date,

    however, they have not lived up to expectations. Many expert

    systems help human experts in such fields as medicine and

    engineering, but they are very expensive to produce and are helpful

    only in special situations.

    Today, the hottest area of artificial intelligence is neural networks,

    which are proving successful in a number of disciplines such as voice

    recognition and natural-language processing.

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    ITEC 1010 Information and Organizations

    Artificial Intelligence (6)

    There are several programming languages that are known as AI

    languages because they are used almost exclusively for AI

    applications. The two most common are LISP and Prolog.

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    ITEC 1010 Information and Organizations

    Overview of Expert Systems

    Can

    Explain their reasoning or suggested decisions

    Display intelligent behavior Draw conclusions from complex relationships

    Provide portable knowledge

    Expert system shell A collection of software packages and tools

    used to develop expert systems

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    ITEC 1010 Information and Organizations

    Limitations of Expert Systems

    Not widely used or tested

    Limited to relatively narrow problems

    Cannot readily deal with mixed knowledge Possibility of error

    Cannot refine own knowledge base

    Difficult to maintain May have high development costs

    Raise legal and ethical concerns

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    ITEC 1010 Information and Organizations

    Capabilities of Expert Systems

    Strategic goal setting

    Decision making

    Planning

    Design

    Quality control and monitoring

    Diagnosis

    Explore impact of strategic goals

    Impact of plans on resources

    Integrate general design principles and

    manufacturing limitations

    Provide advise on decisions

    Monitor quality and assist in finding solutions

    Look for causes and suggest solutions

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    ITEC 1010 Information and Organizations

    When to Use an Expert System (1)

    Provide a high potential payoff orsignificantly reduced downside risk

    Capture and preserve irreplaceable humanexpertise

    Provide expertise needed at a number of

    locations at the same time or in a hostileenvironment that is dangerous to humanhealth

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    ITEC 1010 Information and Organizations

    When to Use an Expert System (2)

    Provide expertise that is expensive or rare

    Develop a solution faster than human

    experts can

    Provide expertise needed for training and

    development to share the wisdom of human

    experts with a large number of people

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    ITEC 1010 Information and Organizations

    Components of an

    Expert System (1) Knowledge base

    Stores all relevant information, data, rules, cases, andrelationships used by the expert system

    Inference engine Seeks information and relationships from the

    knowledge base and provides answers, predictions,and suggestions in the way a human expert would

    Rule A conditional statement that links given conditions to

    actions or outcomes

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    ITEC 1010 Information and Organizations

    Components of an

    Expert System (2) Fuzzy logic

    A specialty research area in computer science thatallows shades of gray and does not require everything

    to be simply yes/no, or true/false

    Backward chaining A method of reasoning that starts with conclusions and

    works backward to the supporting facts

    Forward chaining A method of reasoning that starts with the facts and

    works forward to the conclusions Schematic

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    ITEC 1010 Information and Organizations

    Inference

    engine

    Explanation

    facility

    Knowledge

    baseacquisition

    facility

    UserinterfaceKnowledgebase

    Experts User

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    ITEC 1010 Information and Organizations

    Rules for a Credit Application

    Mortgage application for a loan for $100,000 to $200,000

    If there are no previous credits problems, and

    If month net income is greater than 4x monthly loan payment, and

    If down payment is 15% of total value of property, and

    If net income of borrower is > $25,000, and

    If employment is > 3 years at same company

    Then accept the applications

    Else check other credit rules

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    ITEC 1010 Information and Organizations

    Explanation Facility

    Explanation facility

    A part of the expert system that allows a user

    or decision maker to understand how theexpert system arrived at certain conclusions or

    results

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    ITEC 1010 Information and Organizations

    Knowledge Acquisition Facility

    Knowledge acquisition facility

    Provides a convenient and efficient means of

    capturing and storing all components of theknowledge base

    Knowledge

    base

    Knowledge

    acquisitionfacility

    Joe Expert

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    ITEC 1010 Information and Organizations

    Determining requirements

    Identifying experts

    Construct expert system components

    Implementing results

    Maintaining and reviewing system

    Expert Systems Development

    Domain

    The area of knowledge

    addressed by the

    expert system.

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    ITEC 1010 Information and Organizations

    Participants in Expert Systems

    Development and Use Domain expert

    The individual or group whose expertise andknowledge is captured for use in an expert system

    Knowledge user The individual or group who uses and benefits from

    the expert system

    Knowledge engineer Someone trained or experienced in the design,

    development, implementation, and maintenance of anexpert system Schematic

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    ITEC 1010 Information and Organizations

    Expert

    system

    Domain expert

    Knowledge engineer

    Knowledge user

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    ITEC 1010 Information and Organizations

    Evolution of Expert Systems

    Software Expert system shell

    Collection of software packages & tools to design,

    develop, implement, and maintain expert systems

    Ease

    ofuse

    low

    high

    Before 1980 1980s 1990s

    Traditionalprogramming

    languages

    Special and 4th

    generationlanguages

    Expert system

    shells

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    ITEC 1010 Information and Organizations

    Advantages of Expert Systems

    Easy to develop and modify

    The use of satisficing

    The use of heuristics

    Development by knowledge engineers and

    users

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    ITEC 1010 Information and Organizations

    Expert Systems Development

    Alternatives

    low

    high

    low high

    Development

    costs

    Time to develop expert system

    Use

    existing

    package

    Developfrom

    shell

    Develop

    from

    scratch

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    ITEC 1010 Information and Organizations

    Applications of Expert Systems

    and Artificial Intelligence Credit granting Information management and retrieval AI and expert systems embedded in products Plant layout

    Hospitals and medical facilities Help desks and assistance Employee performance evaluation Loan analysis Virus detection

    Repair and maintenance Shipping Marketing Warehouse optimization

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    ITEC 1010 Information and Organizations

    End of Chapter 11

    Chapter 12

    http://1010-chapter12.ppt/http://1010-chapter12.ppt/