Software Architecture

11. “The type of transaction in an input stream triggers selection of process to execute”. Identify the type of repository. 

If the types of transaction in an input stream trigger selection process to execute, the repository can be a traditional database. 

12. What do you mean by a Black board? 

Black board is a repository in which the current state of the central data structure is the main trigger for selecting processes to execute. The black board is usually presented with three major parts: 

1. The knowledge sources 

2. The black board data structure 

3. Control structure 

13. What is an interpreter? 

An interpreter includes the pseudo program being interpreted and the interpretation engine itself. The pseudo program includes the program itself and the interpreter’s analog of its execution state. The interpretation engine includes both the definition of the interpreter and the current sate of its execution. 

14. What are components of an interpreter? 

The components of an interpreter include: . 

An interpretation engine to do work 

. A Memory that contains the pseudo code to be interpreted 

. A representation of the control state of the interpretation engine 

. A representation of the current state of the program being simulated. 

15. What is a set point? 

Set point is the desired value for a controlled variable. 

16. Define Open-loop system. 

Open-loop system is defined as the system in which information about process  variables is not used to adjust the system. 

17. Define Closed-loop system. 

Closed-loop system is defined as the system in which information about process variables is used to manipulate a process variable to compensate for variations in process variables and operating conditions. 

18. Define Feedback control system. 

Feedback control system is defined as the controlled variable is measured, and the result is used to manipulate one or more of the process variables. 

19. Define Feedforward control system. 

Feedforward control system is defined as the process variables are measured, and anticipated disturbances are compensated for without waiting for changes in the controlled variable to be visible. 

20. What are process variables? 

Process variables are the properties of the process that can be measured; several specific kinds are often distinguished. 

21. What are controlled variable? 

Controlled variables are the process variable whose value the system is intended to control. 

22. What are manipulated variable? 

Manipulated variables are process variable whose value can be changed by the controller. 

23. Define State transition systems. 

State transition systems are defined in terms of a set of states and a set of named transitions that move a system from one state to another. 

24. Write about Domain-specific architecture. 

By specializing the architecture to the domain, it is possible to increase the descriptive power of structures. Such type of architectures are called Domain-specific architecture. 

25. What is Heterogeneous architecture? 

The combination of several “pure” architectural styles in several ways is called Heterogeneous architecture.