1. e olmstead Knowledge Industries, Inc. January 27, 2002 1

2. 2 Building a Diagnostic Bayes Net using the Knowledge Industries, Inc. DXSolution Series Software

3. e olmstead Knowledge Industries, Inc. January 27, 2002 3 Describe the Domain Graphically Use the KI Graphics Editor to draw lines and bubbles Show the flow of Cause and Effect with the arrow heads At each node enter the Prior Probabilities using the Node Editor BBN is a diagnostic for making Bread

4. e olmstead Knowledge Industries, Inc. January 27, 2002 4 Bread Failure Diagnostic Node Graph is made as the first step in construction of the Diagnostic Solution. The KI Graphics Editor enables the construction of the Node Graph. Each Node has a set of tables that define the nature of the Node and the Prior Probabilities. The arrow heads are usually in the causal direction. Enter the Prior Probabilities

5. e olmstead Knowledge Industries, Inc. January 27, 2002 5 Two Basic types of Nodes Observables – that are the input evidence to the BBN. This ordered list is sequenced by a calculation of the Value of Information (VOI). The most significant Observation is always requested first! Faults – that are the results of entering evidence into the BBN. The probability of each Fault, given the state of the Observables, is calculated at each stage of the diagnosis.

6. e olmstead Knowledge Industries, Inc. January 27, 2002 6 There are two basic types of Nodes – Observables and Faults. The darker Nodes are the Observables,

7. e olmstead Knowledge Industries, Inc. January 27, 2002 7 The Faults Nodes are darkened here.

8. e olmstead Knowledge Industries, Inc. January 27, 2002 8 Other Node Types Nodes may also be: Unobservable Mandatory and Observable Mandatory and Unobservable The Questions (test) associated with each Recommended Test is entered on the form.

9. e olmstead Knowledge Industries, Inc. January 27, 2002 9 The Node Graph can also bee seen and modified with a Group Editor.

10. e olmstead Knowledge Industries, Inc. January 27, 2002 10 The Data Editor enabls entry of “costs” for each observable and the introduction of comments.

11. e olmstead Knowledge Industries, Inc. January 27, 2002 11 Testing and Validation Internal consistency of the BBN is always assured – it will not compile if there are inconsistencies Correspondence with the domain being diagnosed is confirmed by test cases Domain Experts work with the builders to describe valid test cases and confirm diagnosis

12. e olmstead Knowledge Industries, Inc. January 27, 2002 12 WIN-DX The Test and Validation System The compiled BBN generated by the Graphics Editor/Compiler can be evaluated and tested during construction of the BBN May also be used by some users but most prefer to integrate the Inference Engine (API-dll) into their own System Initial calculations reflect the influence of the Prior Probabilities

13. e olmstead Knowledge Industries, Inc. January 27, 2002 13 After the Node Graph is compiled the BBN may be examined and tested using the WIN-DX component. This software allows all of the funtionality of the compiled Bayes Net to be explored. This screen shows the BBN prior to the introduction of any Obervables – that is, no tests have been made – only the Prior probabilities are considered in calculating the Possible Disorders, The Recommended Test (best next question) is calculated using the KI VOI (patent pending) technology.

14. e olmstead Knowledge Industries, Inc. January 27, 2002 14 The results of the first Recommended Test (the first Observable) have been introduced and the Possible Disorders has been recalculated using this new information. The input for the first Recommended Test is shown in the Worksheet box where it can be retracted or changed to explore the operation of the BBN.

15. e olmstead Knowledge Industries, Inc. January 27, 2002 15 The second Observable has been entered and the Possible Disorders has been calculated to reflect the additional information.

16. e olmstead Knowledge Industries, Inc. January 27, 2002 16 Other Graphics BBNs Segment of a BBN used in a commercial Relay Frame Testing system for Telecommunications testing Diagnostic for the Auxiliary Power Unit jet engine Modem diagnostic

17. e olmstead Knowledge Industries, Inc. January 27, 2002 17 A segment of a Node Graph for a BBN diagnostic for telecommunication test equipment. This BBN was integrated into the operation of a Frame Relay test system.

18. e olmstead Knowledge Industries, Inc. January 27, 2002 18 A Single Fault Node BBN for diagnosis of a jet engine used in commercial aviation.

19. e olmstead Knowledge Industries, Inc. January 27, 2002 19 A Node Graph for diagnosis of a telecommunications interface system.

20. e olmstead Knowledge Industries, Inc. January 27, 2002 20 End