--%>
Assignment Help - homework help

Describe Data Independence

Data Independence: A system is data independent if the values of the infinite program data it manipulates are not relevant to the behavior of the system—for example, a protocol that transmits messages may be proved correct regardless of the contents of the messages that are transmitted. It has been shown (Wolper 1985) that reasoning about pair-wise message ordering properties over a communication channel that accepts large domains of values can be achieved by using an abstract domain of size three. Note that this kind of reasoning is possible only when the values that are passed through the channel are not modified or tested by the program (i.e., the program is data independent). The three-valued abstract domain {d1, d2, other} provides the ability to distinguish between two concrete elements, but it abstracts from their values. Such an abstraction can be thought of as a “symbolic” Set abstraction, where d1 and d2 are placeholder for any two different values of a particular concrete data domain, while all the other values are abstracted to other.

   Related Questions in Science

  • Q : Search out whats your shell Normal 0

    Normal 0 false false

  • Q : Main components of control loop Main

    Main components of control loop: A closed control loop in a very fundamental manner comprises of transmitter, sensor, controller, signal converters and final control elements. In reality in a practical loop there will be numerous other instruments apa

    		•
  • Q : What is Property Specification in Java

    Property Specification in Java PathFinder: In Java PathFinder, properties are specified in Java. JPF can check a number of properties out of the box: No Deadlocks No Assertion Violation No Uncaught Exceptions (i.e.,

    		•
  • Q : State Behavior Approximation Behavior

    Behavior Approximation: Abstractions are also described in term of the relative behavior of the abstract system versus the concrete system. A program’s “behavior” is defined as the set of possible execution paths, also called traces

    		•
  • Q : Several registers in 8085 Normal 0

    Normal 0 false false

  • Q : Define Models Models: Building an

    Models: Building an accurate model of the system is a major and critical step in program model checking. You need to create models of both the application to be model checked and the environment in which it is run, including all the input data and eve

    		•
  • Q : Describe raid Normal 0 false false

    Normal 0 false false

  • Q : DuplicateHandle Normal 0 false false

    Normal 0 false false

  • Q : Describe publish or subscribe model

    Publish/subscribe model: This is an approach to distributed system communication wherein publishers publish information to a subject address & subscribers subscribe to information at subject address. This model has the benefit of making publishers

    		•
  • Q : Explain Loader Loader: In a computer

    Loader: In a computer operating system, the loader is a component which locates a particular program (that can be an application or, in some situations, part of the operating system itself) in offline storage (like a hard disk), loads it into major st

    		•