1. Course Instructor: K ashif I hsan 1

2. Chapter # 2 Kashif Ihsan, Lecturer CS, MIHE2

3. Expert Dictionary Meaning: A person with a status of an authority in a specific subject due to special skills, training or knowledge. Other name for an expert is Specialist. A person who has certain expertise or who has acquired skills from experience. Kashif Ihsan, Lecturer CS, MIHE3

4. Imagine ? Imagine a piece of software that runs on your PC which provides the same sort of interaction and advice as a career counselor helping you decide what education field to go into and perhaps what course to pursue. OR A piece of software which asks you questions about your defective TV and provides a diagnosis about what is wrong with it. Such software, called expert systems, actually exist. Kashif Ihsan, Lecturer CS, MIHE4

5. Definition “An expert system is a computer system that emulates, or acts in all respects, with the decision- making capabilities of a human expert.” Expert system is highly specialized piece of software that attempts to duplicate the function of an expert. Kashif Ihsan, Lecturer CS, MIHE5

6. Expert System The program (Expert System) acts an intelligent consultant or advisor in the domain of interest, capturing the knowledge of one or more experts. An Inference means a conclusion drawn from data. Most of the expert systems in the market today are the prototypes and laboratory experiments. Kashif Ihsan, Lecturer CS, MIHE6

7. Structure of Expert System Kashif Ihsan, Lecturer CS, MIHE7

8. Structure of Expert System Kashif Ihsan, Lecturer CS, MIHE8

9. Knowledge Base Explicit (well defined) & Human Readable  Editable  Preserve Knowledge of Experts Knowledge Representation  Rules Fixed Part  Generic rules Dynamic Part  Problem Specific Data Kashif Ihsan, Lecturer CS, MIHE9

10. Knowledge Base The knowledge base (also called rule base when If- then rules are used) is a set of rules which represents the knowledge about the domain. The general form of a rule is: If cond1 and cond2 and cond3... { then action1, action2,... } Kashif Ihsan, Lecturer CS, MIHE10

11. Inference Engine An inference engine is a computer program that tries to derive answers from a knowledge base. It is the "brain" that expert systems use to reason about the information in the knowledge base for the ultimate purpose of formulating new conclusions. Kashif Ihsan, Lecturer CS, MIHE11

12. Inference Engine The inference engine is the program part of an expert system. It represents a problem solving model which uses the rules and the situation-specific knowledge in the knowledge base to solve a problem. Kashif Ihsan, Lecturer CS, MIHE12

13. User Interface The front end that enables to communicate with the inference engine & knowledge base is called the User Interface of an expert system. Text Based (using commands). Menu Based (Graphical User Interface). Kashif Ihsan, Lecturer CS, MIHE13

14. Working Memory Working memory is the global database of facts used by rules of knowledge base. Kashif Ihsan, Lecturer CS, MIHE14

15. Rule-Based Expert System Kashif Ihsan, Lecturer CS, MIHE15

16. Types of Expert System Following is a list of major types of Expert System:  Diagnosis  Repair  Instruction  Interpretation  Prediction  Design & Planning  Monitoring & Control Kashif Ihsan, Lecturer CS, MIHE16

17. Diagnosis Diagnosis types of expert systems are used to recommend remedies to illnesses, trouble-shoot electronic or mechanical problems or as debugging tools. Kashif Ihsan, Lecturer CS, MIHE17

18. Repair Expert systems that define repair strategies are also very common. As well as diagnosing the problem, they can suggest a plan for the repair of the item. Such systems have been employed in the automotive repair field and similar areas. Kashif Ihsan, Lecturer CS, MIHE18

19. Instruction Instructional expert systems have been used for training or instruction in a particular field. This system presents material in an order determined by its evaluation of the user’s ability and current knowledge and monitor’s the progress of the student, altering the sequence depending on this progress. Kashif Ihsan, Lecturer CS, MIHE19

20. Interpretation Interpretive expert systems have the ability to analyze data to determine its significance or usefulness. The knowledge base often contains models of real world situations which it compares to its data. These are often used in exploration for mineral, gas and oil deposits as well as in surveillance, image analysis and speech understanding. Kashif Ihsan, Lecturer CS, MIHE20

21. Prediction Predictive expert systems are used as a method to “guess” at the possible outcomes of observed situations, usually providing a probability factor. This is used often in weather forecasting. Kashif Ihsan, Lecturer CS, MIHE21

22. Design & Planning This allows experts to quickly develop solutions that save time. These systems do not replace experts but act as a tool by performing tasks such as costing, building design, material ordering, etc. Kashif Ihsan, Lecturer CS, MIHE22

23. Monitoring & Control In certain applications, expert systems can be designed to monitor operations and control certain functions. These are particularly useful where speed of decision making is vitally important, for example in the nuclear energy industry, air traffic control and the stock market. Kashif Ihsan, Lecturer CS, MIHE23

24. Knowledge Engineering The process of building an expert system:  The knowledge engineer establishes a dialog with the human expert to elicit knowledge.  The knowledge engineer codes the knowledge explicitly in the knowledge base.  The expert evaluates the expert system and gives a critique to the knowledge engineer. Kashif Ihsan, Lecturer CS, MIHE24

25. Development of an Expert System Kashif Ihsan, Lecturer CS, MIHE25

26. The End ( Part - 1 ) Kashif Ihsan, Lecturer CS, MIHE26