System Modelling 2019/1 -- Theoretical Questions 1
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. The difference between the model and the reality is that ...
1/a ... the model may also describe a not yet existing system (a planned one). *
1 point
1/b ... the reality shows a simplified picture of the model. *
1 point
1/c ... the model contains mainly information only, that is relevant to a given problem/question. *
1 point
1/d ... the model may neglect some properties of the reality. *
1 point
2. If model M1 refines model M2, then ...
2/a ... M2 also refines M1. *
1 point
1 point
1 point
2/d ... M2 abstracts M1. *
1 point
3. S is a state space and S' is an arbitrary set of states. In this case ...
3/a ... S \ S' is always mutually exclusive. *
1 point
3/b ... S \ S' is always mutually exclusive. *
1 point
3/c ... S ∪ S' is always complete. *
1 point
3/d ... if S' is a state space, too, then either S ∩ S' = ∅ or S = S’. *
1 point
4. A state machine is always non-deterministic, if ...
4/a ... it has a state from which the state machine may change to the same state upon multiple events. *
1 point
4/b ... it has a state from which multiple unguarded transitions originate that are triggered by the same event but deliver different outputs. *
1 point
4/c ... it has a state that has no outgoing transition defined for each possible events. *
1 point
4/d ... it has a state with one event triggered transition and a spontaneous one, delivering different outputs. *
1 point
5. If one region of a state chart consists of a state machine with 5 states and 10 transitions, and another region consists of one with 6 states and 16 transitions, then the asynchronous product of the two state machines (when it is not yet further refined) ...
5/a … will always be deterministic. *
1 point
5/b … will always contain guards. *
1 point
5/c … will contain less than 100 transitions. *
1 point
5/d … will contain a number of transitions that can be divided by 8. *
1 point
6. What can be the goal of structural modelling?
6/a Examination of the behaviour of the system over time. *
1 point
6/b Decomposition of the system into smaller parts. *
1 point
6/c Examination of the dynamic behaviour of the system. *
1 point
6/d Specifying the relations and connections within the system. *
1 point
7. A tree graph …
7/a … may contain an undirected cycle, but no directed ones. *
1 point
7/b … may represent a containment structure. *
1 point
7/c … still remains a tree graph (or a forest) after filtering by edge labels. *
1 point
7/d … has always a type graph that must contain no loop edges. *
1 point
8. Which statements below are true?
8/a Type graphs describe the temporal changes of property models. *
1 point
8/b A type graph contains one type node for each node type, and one type edge for each edge type. *
1 point
8/c The classes (known from object-oriented programming) correspond to the nodes of a type graph. *
1 point
8/d The objects (known from object-oriented programming) correspond to the nodes of a type graph. *
1 point