1. Advanced Topics in Behavior Analysis - Page L15-1 Full 2002Dr. M.E. Fayad Lesson 15: Advanced Topics in Behavior Analysis Object- Oriented Modeling & Application s

2. Advanced Topics in Behavior Analysis - Page L15-2 Full 2002Dr. M.E. Fayad Lesson Objectives oDescribe the characteristics of Real-Time Systems oUnderstand action tables oUnderstand picket fence representation oLearn about timing diagram oUnderstand leveling behavior models oLearn about concurrency

3. Advanced Topics in Behavior Analysis - Page L15-3 Full 2002Dr. M.E. Fayad Characteristics of Real-Time Systems Problems are formulated in scientific or engineering terms RTSs contain sensors and actuators to interact with their environment instead of with humans –A RTS has sensors to sense important physical parameters, such as temperature, pressure, or speed –A RTS has actuators, such as valves and thermostats that can make direct changes to the environment without going through a human intermediary. –Require a degree of coordination similar to the eye-hand coordination of people. RTSs often require concurrent processing of multiple inputs - Examples: –Temperature, pressure, acidity may have to be sensed and used together to calculate how to control a chemical reaction. –Valves and heaters may have to be adjusted simultaneously to maintain the desired flow rate, temperature, and reaction rate.

4. Advanced Topics in Behavior Analysis - Page L15-4 Full 2002Dr. M.E. Fayad Characteristics of Real-Time Systems RTSs operate at very short time scales –Systems like a nuclear reactor may responses in milliseconds or even microseconds. –Such rapid response times may sometimes be at the limit of the available technology. –As a result, there may be several technological constraints in the design of the system. RTSs require higher precision than ordinary systems. Constraints are imposed by the task, not the user –These constraints guarantee safety, liveness, and timeliness –Safety means that responses match specifications and the system is fault-tolerant –Liveness means that the system responds to all events –Timeliness means that the system responds within time constraints imposed by the environment

5. Advanced Topics in Behavior Analysis - Page L15-5 Full 2002Dr. M.E. Fayad Comments on the Characteristics of RTSs The list of previous RTS characteristics is not mandatory A method for designing RTSs must be able to deal with all of the RTS characteristics. There are no method deals with all the characteristics Methods for RTS developments: –ROOM –Berard –O-ET

6. Advanced Topics in Behavior Analysis - Page L15-6 Full 2002Dr. M.E. Fayad STD for the Control Temperature Process Start Stop Idle State Gas Heating Electric Heating Cold Enable Gas Cold Enable Gas Refrigeration Cold or Cool Enable Electric Cool Disable Gas OK Disable Electric Cold oe Cool Disable Refrig’n Hot Disable Electric Enable Refrig’n Hot Enable Refrig’n

7. Advanced Topics in Behavior Analysis - Page L15-7 Full 2002Dr. M.E. Fayad An Action Table Equivalent to previous STD STATUS SIGNALS Cold Cool OKHot Idle Gas Heat Electric Heat Refrigeration Enable Gas Enable Electric Disable Refrig’n Idle Disable Electric Enable Refrig’n Disable Electric Idle Enable Refrigeration Disable Gas Enable Gas Disable Refrig’n Idle

8. Advanced Topics in Behavior Analysis - Page L15-8 Full 2002Dr. M.E. Fayad Timing Diagram Idle Warming Running Cooling

9. Advanced Topics in Behavior Analysis - Page L15-9 Full 2002Dr. M.E. Fayad Timing Diagram (cont’d) Timing Diagrams help in understanding a complex sequence of related actions and activities within a thing or between instances A Timing Diagram represents the relative time at which an action or activity occurs Each “row” in the diagram denotes a separate action or activity

10. Advanced Topics in Behavior Analysis - Page L15-10 Full 2002Dr. M.E. Fayad Timing Diagram (cont’d) When the lines are drawn: –Low => the action or activity is considered not to be taken place –High=> the action or activity is considered to be taken place When one activity must precede another, a freehand line can be drawn to show the precedence relationship Timing Diagram can be annotated to show the “birth” and “death” of object instances, and the formation and breakup of relationships, etc.

11. Advanced Topics in Behavior Analysis - Page L15-11 Full 2002Dr. M.E. Fayad Leveling Behavior Models OFFOFF ONON On Off Idle Decelerating Accelerating Running Stopped Done Start At Speed

12. Advanced Topics in Behavior Analysis - Page L15-12 Full 2002Dr. M.E. Fayad Leveling Behavior Models (cont’d) Behavior models can be leveled –Leveling suppresses details to increase understanding –Allows the representation of very large behavior models, in manageable pieces Two popular approaches: –Sub-class/Super-class: Class-based –Composite object structure: Instance-based

13. Advanced Topics in Behavior Analysis - Page L15-13 Full 2002Dr. M.E. Fayad Concurrency Aggregation Concurrency: –A dynamic model describes a set of concurrent objects, each with its state and STD. –The objects in a system are inherently concurrent and can change state independently –The state of the entire system cannot be represented by a single state in a single object; it is the product of the states o all its objects. –Aggregation implies concurrency. »The aggregate state corresponds to the combined states of all the components STDs »Aggregation is the “and” relationship »The aggregate state is one state from the first STD, and a state from the second STD, and a state from each other STD.

14. Advanced Topics in Behavior Analysis - Page L15-14 Full 2002Dr. M.E. Fayad Concurrency (cont’d) Concurrency within an object: –Concurrency within the state of a single object arises when the object can be partitioned subsets of attributes and links, each o which has its own sub-STD. The state of an object comprises one state from each sub-STD

15. Advanced Topics in Behavior Analysis - Page L15-15 Full 2002Dr. M.E. Fayad Define An action table Concurrency Timing Diagram What are the differences between aggregation and concurrency? What are the characteristics of RTSs? Discussion Questions