ns2 project in kerala

ns2 project in kerala


     ns2 project in kerala the remaining two schemas are operation schemas.

Operation schemas have a A-list of those attributes

whose values may change. By convention, no Alist

means no attribute changes value. Every operation ns2 project in kerala

schema implicitly includes the state schema in

un-primed form ,Operation ns2 project in kerala Leaveoutputs a value item! defined as the head of sequence

items and reduces items to the tail of its original value A history invariant is an optional predicate over histories

of objects of the class expressed in temporal logic.

Such predicates further constrain possible behaviour.

For example, suppose we wish to specify in the generic

queue that whenever Leave or Delete is continuously

enabled it must eventually occur. Objects ns2 project in kerala may have object references as attributes] i . 9

conceptually, an object may have constituent objects.

Such references may either be individually named or

occur in aggregates. For example, the declaration, C declares c to be a reference to an object of the class

described by C. A declaration c, d : C need not mean

that c and d reference distinct objects. If the ns2 project in kerala intention

is that they do so at all times, then the predicate c d

would be included in the class invariant.

The term c.att denotes the value of attribute att

of the object referenced by c, and c.Op denotes the

evolution of the object according to the ns2 project in kerala definition of

Op in the class C, A lift system for an multi-floor building consist of

multiple elevators. Inside the elevator there is a ns2 project in kerala panel

of floor buttons each of which indicates a destination

floor. Outside the elevator there are two direction ns2 project in kerala buttons

on each floor which call for service, one for up and

the other for down (except the first floor and ns2 project in kerala the top

floor on which only one button is needed). Any button

can be pushed at any time. Any external floor

button will be on from the time it is pushed until the

elevator with the same travel direction stops at the

floor and opens the door. Any internal ‘on’ button of

a lift will be turned off when the lift visits the corresponding

floor. safety property (S): The lift door must be closed

before any movement (Up or Down).

system property (Pl): When a lift has no ns2 project in kerala request,

it should remain at its final destination.

system property (P2): The lift has to satisfy an

external floor request only if it goes in the same

direction or if the request is the external destination

of the lift. system property (P3): When a request arrives

from a floor the system will put the request at

the end of the external request queue.

system property (P4): If an external request in

the queue is serviced by some lift on the way Up

or Down, then this request should be removed

from the request queue. temporal property (Tl): whenever there are some

idle lifts and the external service queue is not empty, ns2 project in kerala the longest waiting request is

removed from the queue and assigned to one idle lift as the temporal final destination. temporal property (T2): All request for lifts from floors must be serviced eventually. temporal property (T3): All internal requests for

lifts must be serviced eventually. temporal property (T4): If a lift’s door is open,

eventually it will be closed.