"an automated ticket-issuing system used by passengers at a railway station" Code Answer's

an automated ticket-issuing system used by passengers at a railway station

By Ashamed Alpaca on Sep 22, 2020

                           Chapter 10 Exercises



           10.3  Giving reasons for your answers, suggest
                 an appropriate structural model for the
                 following systems:

                 - an automated ticket issuing system used
                   by passengers at a railway station;


                   The most appropriate architectural model 
                   is a centralized model with a shared 
                   repository of route and pricing information. 
                   This means that changes are immediately 
                   available to all machines. As little local 
                   processing is necessary, there is no real 
                   advantage in a client-server architecture. 
                   The centralized system also allows global 
                   information and route use to be collected 
                   and processed.


                 - a computer-controlled video conferencing
                   system which allows video, audio, and
                   computer data to be visible to several 
                   participants at the same time;


                   The most appropriate is a client-server model. 
                   The reason for this is the need for a lot of 
                   local processing to handle multimedia data.


                 - a robot floor cleaner which is intended
                   to clean relatively clear spaces such as
                   corridors.  The cleaner must be able to
                   sense walls and other obstructions.


                   The most appropriate model is a repository 
                   model where all subsystems place information 
                   in the repository for other sub-systems to 
                   use. In the case of AI systems as this would 
                   be, a special kind of repository called a 
                   blackboard is normally used.









           10.5  Explain why a call-return model of control
                 is not usually suitable for real-time 
                 systems which control some process.



                 The call return model assumes a sequence of 
                 actions whereas real-time systems must respond 
                 to events from different hardware interfaced to 
                 the system. This normally means that the control 
                 must be responsive rather than sequential.



           10.6  Giving reasons for your answer, suggest an
                 appropriate control model for the following
                 systems:

                 - a batch processing system which takes
                   information about hours worked and pay
                   rates and prints salary slips and bank
                   credit transfer information;


                   Call return model of control. Each operation 
                   involves identifying particular options then 
                   calling subroutines to retrieve or compute 
                   the required information. There are no 
                   unexpected events to be processed


                 - a set of software tools which are produced
                   by different vendors but which must work
                   together;

                   
                   Broadcast model of control is most appropriate. 
                   Tools need not know which other tools are 
                   available and this approach allows tools which 
                   operate on different types of computers to work 
                   together.


                 - a television controller which responds to
                   signals from a remote control unit.


                   Centralized (polling) control model. This is 
                   the most appropriate approach as there is no 
                   need for the very rapid response required from
                   interrupt driven systems.

Source: www.cise.ufl.edu

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