[Q] How to do simulation in ADA?

[joechan@poboxes.com (Joe Chan - �� �~ ��)]

Hi,
        I need to write a ADA program to simulate the operation of a
control system which controls the RPM(revolutions per minute) of
the turbine in a nuclear power plant. The RPM depends on the
pressure(X) and the flow rate of cooling liquid(U).

        Their relationship can be described by the following equation:

        RPM = 100(1-10U/X)(1-U/100)

        There is a optimal operation point(i.e. a fixed value for RPM,
X, U) that all the deviations must converage.
                                        -at
        The correction by U is D = 1 - e   ,
        where a = U          , D = RPM          , t = time
                   difference         difference
        
                                        -bt
        The correction by X is F = 1 - e   ,
        where b = X          , F = RPM          , t = time
                   difference         difference

        If both U and X change at the same time, the closer point
(absolute value) to the optimal operation point is the new reference
point of operation.

        The initial operation point is X=13, U=0.8

        My questions:

        1. How to program 3 tasks to sample the RPM, U and X?
        2. Generate a random number to decide whether a sampling
should start? (Is there any random number geneartor in VAX ADA?)
                               -ct
        3. How to program 1 - e   ? (Is there any exp function?)

        4. Could you tell me which book describes the similar software
system?

	I am a beginner in ADA programming! Any suggestions are welcome!

	Thank you very much!

	Joe

P.S. Could you also mail your response to me, joechan@poboxes.com