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CPE/CSC 481: Knowledge-Based Systems

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Title: CPE/CSC 481: Knowledge-Based Systems Author: Franz J. Kurfess Last modified by: Franz J. Kurfess Created Date: 2/24/2009 10:45:29 PM Document presentation format – PowerPoint PPT presentation

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Title: CPE/CSC 481: Knowledge-Based Systems


1
CPE/CSC 481 Knowledge-Based Systems
  • Dr. Franz J. Kurfess
  • Computer Science Department
  • Cal Poly

2
Usage of the Slides
  • these slides are intended for the students of my
    CPE/CSC 481 Knowledge-Based Systems class at
    Cal Poly SLO
  • if you want to use them outside of my class,
    please let me know (fkurfess_at_calpoly.edu)
  • I usually put together a subset for each quarter
    as a Custom Show
  • to view these, go to Slide Show gt Custom
    Shows, select the respective quarter, and click
    on Show
  • To print them, I suggest to use the Handout
    option
  • 4, 6, or 9 per page works fine
  • Black White should be fine there are few
    diagrams where color is important

3
Course Overview
  • Introduction
  • Knowledge Representation
  • Semantic Nets, Frames, Logic
  • Reasoning and Inference
  • Predicate Logic, Inference Methods, Resolution
  • Reasoning with Uncertainty
  • Probability, Bayesian Decision Making
  • Expert System Design
  • ES Life Cycle
  • CLIPS Overview
  • Concepts, Notation, Usage
  • Pattern Matching
  • Variables, Functions, Expressions, Constraints
  • Expert System Implementation
  • Salience, Rete Algorithm
  • Expert System Examples
  • Conclusions and Outlook

4
Overview ES Examples
  • Motivation
  • Objectives
  • Chapter Introduction
  • Review of relevant concepts
  • Overview new topics
  • Terminology
  • R1/XCON
  • System Configuration
  • Knowledge Representation
  • Reasoning
  • MYCIN
  • Human Resources ES
  • OSHA Hazard Awareness Advisor
  • Gensym G2 Real-Time Expert System
  • Important Concepts and Terms
  • Chapter Summary

5
Logistics
  • Introductions
  • Course Materials
  • textbooks (see below)
  • lecture notes
  • PowerPoint Slides will be available on my Web
    page
  • handouts
  • Web page
  • http//www.csc.calpoly.edu/fkurfess
  • Term Project
  • Lab and Homework Assignments
  • Exams
  • Grading

6
Bridge-In
7
Pre-Test
8
Motivation
  • reasons to study the concepts and methods in the
    chapter
  • main advantages
  • potential benefits
  • understanding of the concepts and methods
  • relationships to other topics in the same or
    related courses

9
Objectives
  • regurgitate
  • basic facts and concepts
  • understand
  • elementary methods
  • more advanced methods
  • scenarios and applications for those methods
  • important characteristics
  • differences between methods, advantages,
    disadvantages, performance, typical scenarios
  • evaluate
  • application of methods to scenarios or tasks
  • apply
  • methods to simple problems

10
Evaluation Criteria
11
R1/XCON
  • one of the first commercially successful expert
    systems
  • application domain
  • configuration of minicomputer systems
  • selection of components
  • arrangement of components into modules and cases
  • approach
  • data-driven, forward chaining
  • consists of about 10,000 rules written in OPS5
  • results
  • quality of solutions similar to or better than
    human experts
  • roughly ten times faster (2 vs. 25 minutes)
  • estimated savings 25 million/year

12
System Configuration
  • complexity
  • tens or hundreds of components that can be
    arranged in a multitude of ways
  • in theory, an exponential problem
  • in practice many solutions don't make sense'',
    but there is still a substantial number of
    possibilities
  • components
  • important properties of individual components
  • stored in a data base
  • constraints
  • functional constraints derived from the functions
    a component performs
  • e.g. CPU, memory, I/O controller, disks, tapes
  • non-functional constraints
  • such as spatial arrangement, power consumption,

13
Knowledge Representation
  • configuration space
  • constructed incrementally by adding more and more
    components
  • the correctness of a solution often can only be
    assessed after it is fully configured
  • subtasks are identified
  • make the overall configuration space more
    manageable
  • component knowledge
  • retrieved from the external data base as needed
  • control knowledge
  • rules that govern the sequence of subtasks
  • constraint knowledge
  • rules that describe properties of partial
    configurations

14
Example Component
  • partial description of RK611 disk controller
  • facts are retrieved from the data base and then
    stored in templates

RK611 Class UniBus module Type disk
drive Supported yes Priority Level buffered
NPR Transfer Rate 212 . . .
15
Example Rule
  • rules incorporate expertise from configuration
    experts, assembly technicians, hardware
    designers, customer service, etc.
  • Distribute-MB-Devices-3
  • If the most current active context is
  • distributing Massbus devices
  • there is a single port disk drive that has not
    been
  • assigned to a Massbus
  • there are no unassigned dual port disk drives
  • the number of devices that each Massbus
  • should support is known
  • there is a Massbus that has been assigned
  • at least one disk drive and that should support
  • additional disk drives
  • the type of cable needed to connect the disk
    drive
  • to the previous device is known
  • Then assign the disk drive to the Massbus

16
Configuration Task
  • check order identify and correct omissions,
    errors
  • configure CPU arrange components in the CPU
    cabinet
  • configure UniBus modules put modules into boxes,
    and boxes into expansion cabinets
  • configure panels assign panels to cabinets and
    associate panels with modules
  • generate floor plan group components and devices
  • determine cabling select cable types and
    calculate distances between components
  • this set of subtasks and its ordering is based on
    expert
  • experience with manual configurations

17
Reasoning
  • data-driven (forward chaining)
  • components are specified by the customer/sales
    person
  • identify a configuration that combines the
    selected components into a functioning system
  • pattern matching
  • activates appropriate rules for particular
    situations
  • execution control
  • a substantial portion of the rules are used to
    determine what to do next
  • groups of rules are arranged into subtasks

18
Performance Evaluation
  • notoriously difficult for expert systems
  • evaluation criteria
  • usually very difficult to define
  • sometimes comparison with human experts is used
  • empirical evaluation
  • Does the system perform the task satisfactorily?
  • Are the users/customers reasonably happy with it?
  • benefits
  • faster, fewer errors, better availability,
    preservation of knowledge, distribution of
    knowledge, etc.
  • often based on estimates

19
Development of R1/XCON
  • R1 prototype
  • the initial prototype was developed by Carnegie
    Mellon University for DEC
  • XCON commercial system
  • used for the configuration of various
    minicomputer system families
  • first VAX 11/780, then VAX 11/750, then other
    systems
  • reimplementation
  • more systematic approach to the description of
    control knowledge
  • clean-up of the knowledge base
  • performance improvements

20
Extension of R1/XCON
  • addition of new knowledge
  • wider class of data
  • additional computer system families
  • new components
  • refined subtasks
  • more detailed descriptions of subtasks
  • revised descriptions for performance or
    systematicity reasons
  • extended task definition
  • configuration of clusters''
  • tightly interconnected multiple CPUs
  • related system XSEL
  • tool for sales support

21
Summary R1/XCON
  • commercial success
  • after initial reservations within the company,
    the system was fully accepted and integrated into
    the company's operation
  • widely cited as one of the first commercial
    expert systems
  • domain-specific control knowledge
  • the availability of enough knowledge about what
    to do next was critical for the performance and
    eventual success of the system
  • suitability of rule-based systems
  • appropriate vehicle for the encoding of expert
    knowledge
  • subject to a good selection of application domain
    and task

22
MYCIN
  • based on a presentation by
  • Adam Gray, CSC 481 W04
  • some modifications by Franz J. Kurfess, W05, W06

A. Gray, 2004
23
Overview
  • History
  • DENDRAL
  • MYCIN
  • Background
  • Knowledge Representation
  • Knowledge Manipulation
  • Uncertainty
  • Performance Evaluation
  • Advantages and Problems
  • References

A. Gray, 2004
24
DENDRAL
  • Commonly considered the first expert system
  • Developed at Stanford in the late 1960s
  • Ed Feigenbaum (a CSC Professor)
  • Bruce Buchanan (a philosopher turned computer
    scientist)
  • Joshua Lederberg (a Nobel Laureate Geneticist)
  • Analyzed NMR mass spectrogram data to determine
    the geometric arrangement of atoms in a molecule

A. Gray, 2004
25
MYCIN Background
  • Medical expert system
  • Developed at Stanford in the 1970s by Feigenbaum,
    Buchanan and Ted Shortliffe (a doctor)
  • Recommended therapy for blood/meningitis
    infections
  • the diagnosis normally involved growing cultures
    of the infecting organism (48 hours)
  • Doctors had to come up with quick guesses about
    likely problems
  • Prescribe drugs to deal with immediate problems
  • Developed to explore how doctors make these
    rough, but important, guesses with partial
    information
  • Also important in practice as there are many
    junior doctors or non-specialized doctors

A. Gray, 2004
26
MYCIN Implementation
  • Goal-directed system that uses a basic
    backward-chaining technique
  • 450 Rules written in LISP
  • Performed as well as some experts and
    significantly better than junior doctors
  • Never actually used in practice
  • Not due to its performance
  • But rather ethical and legal issues

A. Gray, 2004
27
Example Rule
  • If
  • The site of the culture is blood
  • The gram of the organism is neg
  • The morphology of the organism is rod
  • The burn of the patient is serious
  • Then
  • there is weakly suggestive evidence (0.4) that
    the identity of the organism is pseudomonas

A. Gray, 2004
28
Representation
  • Rules had no variables, contexts instead
  • MYCIN dealt with a number of implicit variables
  • For example there could be a patient, a culture,
    a few infectious organisms.
  • MYCINs knowledge structured into
    object-parameter-value triples
  • culture would be an object
  • site would be a parameter of culture
  • a possible value of this parameter would be
    blood

A. Gray, 2004
29
Manipulation
  • MYCIN starts out with a rule that says
  • If there is an organism requiring therapy, then,
    compute the possible therapies and pick the best
    one
  • First tries to see if the disease is known
  • if it isnt begins reasoning process
  • Basic routine in MYCIN
  • attempt to find the value of a parameter

A. Gray, 2004
30
Finding Values
  • Depending on the type of data may ask user if the
    value is known
  • Tried to ask the most general question possible,
    so as not to become annoying or repetitive
  • E.g., if MYCIN wants to know if morphology of
    organism is rod, will ask What is morphology of
    organism? rather than a specific question
    repeatedly
  • Format of KR is supposed to make questions
    reasonable
  • If the value is not know, MYCIN does backward
    chaining
  • Stores a list of rules that might yield a value
    for each parameter

A. Gray, 2004
31
Uncertainty
  • Medical field must reason in the presence of
    unknown, incomplete, vague or uncertain
    information
  • MYCIN used certainty factors
  • initially hard to defend from a sound theoretical
    viewpoint
  • theoretical foundations were established later
    (Dempster-Shafer)
  • useful to see where knowledge about uncertainty
    exists, and the implications it has for the
    design of the system

A. Gray, 2004
32
Certainty Factors
  • Range from 1 (positive it is not the case) to 1
    (positive it is the case).
  • MYCIN maintains certainty for
  • possible values of parameters (ultimately, the
    certainty that you have a particular disease)
  • can maintain multiple possible values, each with
    its own certainty
  • validity of a rule
  • MYCIN has rules for combining the certainty
    factors

A. Gray, 2004
33
Performance Evaluation
  • Shortliffe used
  • 10 sample problems
  • 8 other therapy recommenders
  • 5 faculty at Stanford Med. School, 1 senior
    resident, 1 senior postdoctoral researcher, 1
    senior student
  • 8 impartial judges gave 1 point per problem
  • Max score was 80
  • MYCIN 65, Faculty 40-60, Fellow 60, Resident
    45, Student 30

A. Gray, 2004
34
Controls
  • Judges bias for/against computers
  • Judges did not know who recommended each therapy
  • Difficulty of problems
  • Medical student did badly, so problems not easy
  • Level of Interest
  • Hypothesis in MYCIN that knowledge is power
  • Have groups with different levels of knowledge

A. Gray, 2004
35
Good Points
  • MYCIN was good in that
  • It could calculate dosages very precisely
  • Dealt well with interactions between drugs
  • An area in which humans have trouble
  • Possesses nice explanation facilities
  • Retrieves and displays relevant rules to offer
    explanation of its behavior

A. Gray, 2004
36
Difficulties
  • Narrow in scope
  • did not scale up well to larger problems
  • Practical concerns
  • Doctors have reservations about advise from
    computers
  • Legal issues

A. Gray, 2004
37
References
  • E. H. Shortliffe, F. S. Rhame, S. G. Axline, S.
    N. Cohen, B. G. Buchanan, R. Davis, A. C. Scott,
    R. Chavez-Pardo, W. J. van Melle. MYCIN A
    computer program providing antimicrobial therapy
    recommendations. Clinical Medicine, (Issue)34,
    1975.
  • E. H. Shortliffe. MYCIN A rule-based computer
    program for advising physicians regarding
    antimicrobial therapy selection. Proceedings of
    the ACM National Congress (SIGBIO Session), 739.
    1974.
  • Giarratano, J. and G. Riley, Expert Systems
    Principles and Programming'' 3rd Edition, PWS
    Publishing Company, 1998.
  • MYCIN A Quick Case Study. lthttp//www.cee.hw.ac
    .uk/alison/ai3notes/section2_5_5.htmlgt.
  • Russel, Stuart J. and Peter Norvig. Artificial
    Intelligence, A Modern Approach. Prentice-Hall,
    Inc., 2003.

A. Gray, 2004
38
Human Resources Expert System
  • expert systems to determine conditions and
    entitlements for public employees in New South
    Wales, Australia
  • main user groups
  • employees
  • managers
  • HR staff
  • accessible via Internet
  • http//www.premiers.nsw.gov.au/WorkAndBusiness/Wor
    kingForGovernment/HRExpert.htm
  • some functionality limited to authorized users
  • not available anymore when tested on 02-19-09
  • developed by Softlaw Corporation
    http//www.softlaw.com.au

39
Objectives
  • improve HR advice and information
  • quality, consistency, timeliness
  • enable value-adding strategic functions
  • e.g. work force planning
  • extend use of technology from transaction-based
    ES to advice and information systems

40
HR Expert Principles
  • enhanced electronic decision tree
  • on-line inquiries from users determine branches
  • accessible via official HR web sites
  • integrated with source documents
  • legislation, personnel handbook, etc.

41
HR Expert Inquiries
42
HR Expert Service History
43
Output
  • summary screens
  • reports
  • letters
  • applications and forms
  • audit reports

44
HR Expert Summary Report
45
HR Expert Full Report
46
Project
  • phase 1 - pilot project
  • 3 agencies, 1,250 staff, conducted in 2002-3
  • demonstrated potential savings, user
    satisfaction, qualitative benefits
  • phase 2
  • extension to all relevant conditions and
    entitlements
  • to be operational by May 2004
  • cited in the report of the Australian Government
    - Information Management office as an example
  • technology
  • legislative rulebase technology, STATUTE Expert,
    by Softlaw Corp., Canberra, Australia,
    http//www.softlaw.com.au

47
Benefits
  • employees
  • immediate and up to date information about
    conditions and entitlements
  • easy access for inquiries
  • improved data for decisions
  • increased equity
  • on-demand generation of reports
  • standardized outputs and audit reports
  • Human Resources
  • direct access to information about entitlements
  • less tedious work
  • e.g. looking up information when employees need
    it
  • reduced need for repetitive work
  • more consistent decisions
  • on-demand generation of reports
  • standardized reports

48
Issues
  • some of the input provided by the users
  • not always accurate, up to date
  • only generic conditions and entitlements
  • special cases not included
  • limited coverage
  • not all laws and regulations included
  • requires computer and Web access
  • commitment and buy-in from staff and employees

49
Status
  • operational and in use
  • update to include recent changes in laws and
    regulations under way
  • current modules
  • Maternity Leave
  • Study Time
  • Extended Leave
  • Recognition of Previous Service
  • Leaving the Service
  • Voluntary Redundancy
  • Travel Compensation, including Meal and Private
    Motor Vehicle Allowances
  • Higher Duties A
  • llowance Salary
  • Packaging Agency
  • List Inquiry

50
RuleBurst Demo
  • a Flash demo of the RuleBurst enviroment is
    available at http//www.ruleburst.com/uploads/file
    s/RuleBurst.html
  • a predecessor of RuleBurst was used to develop
    the HR Expert application

51
References
  • HR Expert Case Study at http//www.agimo.gov.au/re
    sources/ppt/2003/030926sb
  • NSW governmental web site at http//www.premiers.n
    sw.gov.au/WorkAndBusiness/WorkingForGovernment/HRE
    xpert.htm
  • Australian Government Information Management
    Office Report at http//www.agimo.gov.au/publicati
    ons/2004/05/egovt_challenges/accountability/determ
    inations/conclusion
  • Softlaw Corporation Web site http//www.softlaw.co
    m.au
  • Softlaw HR Expert Announcement http//www.softlaw.
    com.au/content.cfm?categoryid12topicid49infopa
    geid152
  • RuleBurst KB Development Environment
    http//www.ruleburst.com/
  • sites visited 03-02-05, 02-28-06

52
OSHA Hazard Awareness Advisor
  • asks questions about workplace activities,
    equipment, materials
  • analyzes the users answers
  • generates a report with common occupational
    hazards, applicable OSHA standards, and contacts
  • developed by the U.S. Department of Labor,
    Occupational Safety Health Administration
    (OSHA)
  • version 1.0 released in September 1999
  • http//www.osha.gov/dts/osta/oshasoft/hazexp.html

53
Objectives
  • to help identify and understand common safety and
    health hazards in the work place
  • especially aimed at small businesses
  • designed for beginners
  • may be useful for experts as well
  • widely available through online and downloadable
    versions
  • downloadable version only for MS Windows

54
Limitations
  • may not identify all hazards
  • will not determine compliance with OSHA standards
  • not a substitute for safety and health
    professionals

55
OSHA Principles
  • expert system technology
  • accessible via official OSHA web sites
  • integrated with source documents
  • standards, legislation, etc.

56
Hazard Awareness Advisor Inquiries
57
Hazard Awareness Advisor Report
  • highlights
  • details

58
Report Highlights
  • Evaluate the exposure to chemicals in your
    workplace.
  • Your site needs a hazard communication program.
  • Inspect ladders and ensure that workers know
    how to use them safely.
  • Ladders should be at least 3 feet higher than
    the level they are going to reach.
  • Check that fire exits are unlocked and numerous
    enough for quick escape of all workers.
  • Keep passageways clear of obstructions.
  • Evaluate personal protective equipment that
    your workers purchase for themselves.
  • Protective eye wear may be needed to protect
    against splashes and sprays.
  • Use laser pointers carefully. They can cause
    eye damage.
  • Please investigate the need for head
    protection.
  • Please investigate the need for hard toed
    shoes.
  • Protective gloves may be needed because of
    injuries by knives or other hand tools.
  • Portable fire extinguishers must have
    maintenance service at least once a year and a
    written record must be kept to show the
    maintenance or recharge date.
  • Mark fuse boxes or breaker boxes to identify
    the circuits or equipment they control.
  • Extension cords should not be used as a
    substitute for permanent wiring.
  • Take care when using cleaning solvents and
    liquids when cleaning inside a series of deep
    cabinets or similar spaces.
  • If you have both ammonia and bleach cleaners,
    take care in their storage and use. The mixing of
    ammonia and bleach can produce dangerous chlorine
    gas.

59
OSHA Report Detail Portable Ladders
  • Your answers indicate that your workers use
    portable ladders. The use of any ladder is
    hazardous. Workers may fall from them, fall with
    them, be struck by falling ladders or struck by
    objects dropped from work being performed on the
    ladder.
  • Injuries also result from poor ladder placement
    unstable footing, work angle too steep or too
    shallow, or placement in front of doors or
    passageways. Many serious falls from ladders are
    the result of workers standing above the designed
    working height of the ladder.
  • The hazards of ladder use can be reduced by
    careful selection of ladders of appropriate
    height and strength, by routine inspection and
    maintenance, and by training of workers in safe
    ladder use.
  • In order to safely gain access to an upper level
    such as a roof or platform, the portable or
    extension ladder must extend at least 3 feet
    above the point of contact. Any portable ladders
    should be tied off or held in position during
    use.

60
Project
  • preceded by other SHA advisors
  • Asbestos in '95
  • Confined Spaces in '96
  • Fire Safety in '97
  • Lead in Construction in '98
  • input from
  • National Federation of Independent Business,
  • National Apartment Association,
  • Synthetic and Organic Chemical Manufacturers
    Association,
  • United Brotherhood of Carpenters and Joiners,
  • Laborers Safety and Health Fund,
  • International Brotherhood of Teamsters,
  • other industry and labor organizations

61
Benefits
  • owners/managers
  • easy access for inquiries about potential hazards
  • quick analysis of the workplace
  • generation of a report with highlights, details,
    and pointers for further information
  • employees
  • identification of potential hazards
  • improved working conditions
  • possible compliance issues
  • standards and regulations

62
Issues
  • all of the input provided by the users
  • not always accurate, up to date
  • limited coverage
  • may not identify all hazards

63
Status
  • version 1.0 operational and in use since
    September 1999
  • update to include recent changes in laws and
    regulations ???

64
Other OSHA Expert Advisors
  • see http//www.osha.gov/dts/osta/oshasoft/index.ht
    ml
  • Asbestos
  • Confined Space
  • Electronic Permit Required Confined Spaces
    (e-PRCS)
  • Electronic Health and Safety Plan (e-HASP)
  • Fire Safety
  • Hazard Awareness
  • Lead in Construction
  • Lead in General Industry
  • Lockout/Tagout
  • LOTO Plus
  • SafeCare
  • afety Pays

65
References
  • OSHA Hazard Awareness Advisor, Version 1.0
    September 1999, http//www.osha.gov/dts/osta/oshas
    oft/hazexp.html
  • Stern, Ed (1998) OSHA Unveils Online Hazard
    Awareness Advisor, Access America Government
    Services, http//govinfo.library.unt.edu/accessame
    rica/docs/expertadvisor.html
  • Stern, Ed (1999) The OSHA Hazard Awareness
    Advisor, PC AI Magazine, vol 13, no 2,
    March/April 1999
  • Shirley, Robin E. (200) New OSHA Interactive
    Software Designed to Help Small Business Owners,
    On Target - News for the Small Business Owner,
    http//www.reswritingservices.com/osha.html
  • Virginia Workers Compensation Program (2005)
    Hazard Assessments, http//www.covwc.com/lcartic
    les/archives/000084.php
  • OSHA eTools and Electronic Products for
    Compliance Assistance http//www.osha.gov/dts/osta
    /oshasoft/index.html
  • sites visited 07-14-05, 02-28-06

66
Gensym G2
  • real-time expert system
  • developed by Gensym Corporation
    http//www.gensym.com
  • application areas
  • chemical, oil gas, process manufacturing,
    discrete manufacturing, power utilities, water
    utilities, telecommunications, government,
    transportation, aerospace
  • augmented by additional modules

67
Gensym G2 Platform
68
Gensym G2 Use
http//www.gensym.com/images/pages/g2platform.jpg
69
Gensym Development Cycle
http//www.gensym.com/images/pages/xtreme-programm
ing-lifecycle.jpg
70
Ericsson Network Management System
  • use of G2 for wireless network management
  • challenges in wireless networks
  • additional functionality
  • instant messaging, chat, Web access, photos,
    videos,
  • increased size and complexity of the network
  • very rapid growth and change rate
  • network management can be very stressful
  • constant stream of alarms
  • not all are important
  • extreme pressure to identify and fix problems

71
Ericsson FMX
  • largely automated system for wireless network
    management
  • concentration on the fault management process
  • reacts to all identified events very quickly
  • much faster than humans
  • more reliable
  • but less flexible
  • filters out unimportant messages
  • allows network operators to concentrate on
    critical events
  • consolidates information for critical events
  • manages over 500,000 events per day
  • 500 systems in 100 countries
  • 50 different equipment types
  • benefits
  • increased quality of service
  • reduced operating expenses

72
FMX Screenshot
Input
Condition
Decision
Outputs
http//www.gensym.com/?psuccess_storiesid13
73
Dow Chemicals Closed Loop Optimizer
  • energy management in a large petrochemical plant
    in Seadrift, TX
  • highly interdependent systems
  • real-time control
  • safety-critical
  • very high energy costs
  • utilization of waste heat from gas turbines
  • internal energy usage
  • excess energy sold to the grid
  • manual control of power generation was
    problematic
  • trade-off considerations must be made very fast

74
Energy Management with G2
  • modeling of the energy system
  • sensors provide input
  • important components are modeled
  • output controls actuators, informs operators
  • previous models of individual systems were not
    successful for the overall energy management
  • optimization
  • determines the best operational plan for the
    current conditions in real time

75
Seadrift Functional Diagram
76
Seadrift Screenshot
77
Seadrift Outcome
  • plant ran in closed loop mode 98 percent of the
    time
  • saved Dow 1.25 million dollars in energy costs
    over one year
  • even larger potential for savings
  • extension to other components and systems in the
    plant
  • more sophisticated modeling
  • usage for other plans
  • user satisfaction
  • operators were skeptical initially, but accepted
    and used the system very quickly
  • better view of overall plant operations

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References
  • Gensym Corporation http//www.gensym.com
  • Gensym Success Stories Dow Chemicals
    http//www.gensym.com/?psuccess_storiesid8
  • Dow Chemicals Seadrift Plant http//www.dow.com/uc
    c/locations/seadrift/about/index.htm

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Questions
80
Figure Example
81
Post-Test
82
Evaluation
  • Criteria

83
Important Concepts and Terms
  • agenda
  • backward chaining
  • common-sense knowledge
  • conflict resolution
  • expert system (ES)
  • expert system shell
  • explanation
  • forward chaining
  • inference
  • inference mechanism
  • If-Then rules
  • knowledge
  • knowledge acquisition
  • knowledge base
  • knowledge-based system
  • knowledge representation
  • Markov algorithm
  • matching
  • Post production system
  • problem domain
  • production rules
  • reasoning
  • RETE algorithm
  • rule
  • working memory

84
Summary Chapter-Topic
85
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