System Modelling 2019/1 -- Theoretical Questions 3
Example theoretical questions for practising for the 1st mid-term exam in System Modelling. (In the mid-term exam, you get +1/4 point for each correct answer, -1/4 point for each incorrect ones, and 0 point for each question left out. You have to reach 50% of the possible points in this system. The Google Form is not able to implement this points system.)
1. After performing refinement on any states, tokens or guard conditions of a state machine, …
1/a … the number of states always increases. *
1 point
1/b … the number of states always decreases. *
1 point
1/c … all reachable states of the refined model will have exactly one corresponding state in the abstract model. *
1 point
1/d … all reachable states of the abstract model will have at least one corresponding state in the refined model. *
1 point
2. A state machine is always fully specified if …
2/a … it has an initial state and only one input event, and all states have a transition labeled with this event. *
1 point
2/b … it has an initial state and all possible input events appear as the trigger of at least one transition. *
1 point
2/c … it is the abstraction of a fully specified state machine made by combining two states into one. *
1 point
2/d … it is the refinement of a fully specified state machine made by splitting one state into two. *
1 point
3. If S is a state space and S' is an arbitrary set of spaces, then …
3/a … S \ S' is always mutually exclusive. *
1 point
3/b … S \ S' is always complete. *
1 point
3/c … if S' is also a state space, then S \ S' = ∅. *
1 point
3/d … if S' is also a state space, then S ∩ S' = ∅. *
1 point
4. If one region contains 5 states and 10 transitions and the another one 6 states and 16 transitions, then their asynchronous product without further refinement will have …
4/a … exactly 26 transitions. *
1 point
4/b … exactly 30 transitions. *
1 point
4/c … exactly 140 transitions. *
1 point
4/d … exactly 160 transitions. *
1 point
5. Which ones of the following statements are true?
5/a Filtering always causes a table to have less properties. *
1 point
5/b Filtering can cause a cycle to arise in the property model. *
1 point
5/c Filtering can not cause the number of represented objects to decrease. *
1 point
5/d Projection can cause the number of properties a table has to decrease. *
1 point
6. What can be the goal of structural modelling?
6/a Analysis of the operation of the system over time. *
1 point
6/b Dividing the system into smaller pieces. *
1 point
6/c Analysis of the dynamic behaviour of the system. *
1 point
6/d Defining the relationships and connections inside the system. *
1 point
7. Which ones of the following statements are true?
7/a All undirected graphs can be represented with a directed graph. *
1 point
7/b A graph representing a hierarchy can contain cycles. *
1 point
7/c In a type graph, all node types have a corresponding type node and all edge types have a corrsponding type edge. *
1 point
7/d Objects (known from object oriented programming) correspond to nodes of a type graph. *
1 point