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WorksheetsPreliminary Exam Questions
Total questions: 88
Worksheet time: 1hrs 28mins
What is the cumulative probability for service time of 3 minutes?
0.30
0.60
0.85
1.00
What function prints a complete CSIM report?
report()
print_report();
full_report();
exec_report();
What is simulation?
A real-world experiment
A representation of a system that can be manipulated for analysis
A mathematical equation
A programming language
Which of the following statements about events is FALSE?
Events can be global or local
Events must always be global
Events synchronize processes
Events are initialized to the not-occurred state
A simulation event is:
A function in a program
A change in system state
A type of mathematical equation
A programming error
In the departure routine, what happens when the queue is empty?
The server remains busy
The server becomes idle
The simulation stops
A new customer is added to the queue
In a queuing model, what happens first in the arrival event?
The server is marked busy
The next arrival event is scheduled
The customer delay is set to 0
The number of customers in the queue is updated
Which statement is used to wait for an event to occur?
wait(ev);
hold(ev);
suspend(ev);
process(ev);
What event marks the end of customer process in CSIM?
release();
terminate();
stop();
exit();
How does a process request exclusive access to a facility?
reserve(f);
lock(f);
use(f);
block(f);
What is the purpose of the facility_ms("name", ns); statement?
Create a single server facility
Create a multi-server facility
Allocate storage dynamically
Generate an event
What is CSIM primarily based on?
Java
Python
C
Fortran
A property of an entity is called:
Process
Event
Attribute
State Variable
How busy is Baker compared to Able?
More Busy
Less Busy
Equally Busy
Unknown
What is the probability of time-between-arrival of 4 minutes?
0.125
0.250
0.375
0.500
What is the queue length if utilization is 0.50 in an M/M/1
1.00
0.50
0.25
2.00
CSIM programs are executed by:
Interpreting the code
Compiling the code
Running in a virtual machine
Using a dedicated simulated software
What is model verification?
Ensuring the model is programmed correctly
Comparing the model with a real-world system
Checking if the model procedures unexpected results
Randomly adjusting parameters
In SIMSCRIPT, what does "REQUEST" do?
Assigns a new process
Requests server access
Releases queue entries
Ends the simulation
What are the two types of simulated clock management?
Fixed-time and dynamic-time increment
Fixed-time and variable-time increment
Continuous-time and discrete-time increment
Static-time and adaptive-time increment
Which factor is critical for successful simulation implementation?
End-user involvement
Random modelling
Ignoring system details
Using the most expensive software
The first step in simulation and model building is:
Collecting data
Choosing software
Defining an achievable goal
Validating the model
What is the purpose of statistical output in simulation?
To determine correctness
To analyze simulation results
To debug code
To improve model execution speed
What is the example of continuous-state system?
Number of people in queue
Time spent in a class
Number of cars at a spotlight
Number of packets in a network buffer
A system is:
A random collection of objects
A group of objects interacting toward a purpose
A programming language
A mathematical function
What is a major disadvantage of special-purpose simulation packages?
High software cost
Requires programming skills
Cannot be used for real-world problems
Takes too long to execute
Which of the following is NOT a general-purpose simulation language?
GPSS
SIMSCRIPT
FORTRAN
MODSIM
What is an example of a probabilistic model?
E = mc^2
Bank deposit calculations
A casino game simulation
A simple addition operation
A continuous simulation model:
Changes at discrete time steps
Does not change over time
Changes continuously over time
Uses only mathematical equations
What is an example of a deterministic model?
A stock market simulation
E = mc^2
A weather forecast
A population growth model
What is the purpose of release(f);?
Terminates a process
Resets an event
Release a facility
Returns storage units
What is the simulation language used for GPSS models?
Python
Java
GPSS/H
C++
Which of the following is NOT a type of model?
Physical
Mathematical
Imaginary
Simulation
How is waiting time calculated in SIMSCRIPT?
Arrival time minus service time
Queue length multiplied by service time
Systems clock minus arrival time
Service time minus queue entry time
What is the primary unit of execution in CSIM?
Thread
Event
Process
Task
How are statistics collected in CSIM?
Using the report() function
Through table structures
Using the process classes
All of the above
Which of the following is NOT a step in simulation and model building?
Define an achievable goal
Choose appropriate tools
Randomly pick data
Validate the model
What is the utilization in the CSIM results?
0.50
0.75
0.85
0.99
Which simulation language is object-oriented?
FORTRAN
SIMSCRIPT
MODSIM III
PASCAL
What is the main advantage of simulation over real-world testing?
No cost involved
Results are always 100% accurate
Manipulation the model is easier than manipulating the real system
It eliminates the need for physical systems
Which of the following is NOT a CSIM object?
Processes
Facilities
Threads
Storage blocks
What is the function of clock in CSIM?
Controls process execution
Keeps track of execution cycles
Tracks the current simulation time
Manages event timing
What is a state variable?
A constant value
A variable defining system state
A random number generator
A programming function
What type of simulation does CSIM primarily model?
Real-time systems
Discrete event simulation
Continuous systems
Hybrid systems
Which CSIM object collects data during execution?
Table structures
Events
Mailboxes
Storage blocks
What is a hybrid simulation model?
A model that combines discrete and continuous elements
A purely physical model
A model with no real-world application
A type of programming language
What does storage("name", sz); define?
A queue
A facility
A memory block
An event handler
What is model?
A real-world object
A representation of an object, system, or idea
A random mathematical equation
A physical structure only
What is the main purpose of a queueing model?
To increase customer service times
To analyze system performance under varying loads
To eliminate waiting times completely
To reduce CPU usage in simulations
What is the total number of customers in the simulation findings?
13
18
20
65
What condition triggers an error message in the arrival routine?
If the queue is full
If the server is idle
If the number of customers is even
If there is no arrival event scheduled
Which function checks the status of an event?
status(ev);
state(ev);
check_event(ev);
event_status(ev);
How does a process terminate in CSIM?
stop();
exit();
terminate();
end_process();
What is the purpose of timed_queue(ev, tm);?
Wait for an event or timeout
Create a queue with a timer
Set an event timeout
Suspend process execution
Which step ensures that simulation results are useful?
Model verification
Model execution
Model validation
Model documentation
What is an example of a discrete-time model?
Car speed over time
Number of students attending class
Water flow in a pipe
Temperature changes
What is a common mistake in simulation modelling?
Modelling at the wrong level of detail
Using statistical methods
Using programming languages
Analyzing model results
In GPSS, what activates blocks?
Manual triggers
Entering transactions
Queueing conditions
Random chance
In the M/M/1 queue model, what does "M/M/1 stand for?
Multi-server queue
Single-server with exponential interarrival and service times
Multi-server with limited queue space
Fixed-time deterministic queue
Which is NOT a type of discrete simulation methodology
Event-oriented
Activity-oriented
Process-oriented
Random-oriented
What is the key property of a Markov process?
Dependence on the entire past history
Independence of the past given the present
Dependence on the future given the present
It has only one state
What is the fundamental matrix used for?
To compute transition probabilities in finite steps
To determine the recurrence time of states
To analyze irreducibility
To calculate the equilibrium probabilities
What is the role of policy evaluation in Markov decision processes?
To determine the optimal sequence of actions
To find the stationary distribution
To classify states as transient or recurrent
To compute the probability of reaching state
If a Markov chain has a unique stationary distribution, it means:
The state probabilities do not change over time
The states are transient
The process is deterministic
The transition probabilities sum to more than one
The probability of a Markov chain being in a particular state after n steps is determined by:
The initial state distribution and transition matrix
Only the initial state
Only the transition matrix
The stationary distribution
What is the state space of a Markov chain?
The range of all possible values of Xt
The set of time indices
The set of transition probabilities
The expected number of steps
In a Markov process, what additional element is introduced?
Rewards associated with state transitions
Fixed transition times
Deterministic state transitions
Only absorbing states
What does Pij represent in a Markov chain?
The probability of starting in state i
The probability of transitioning from state i to state j
The probability of remaining in state i
The stationary distribution of state i
What type of distribution describes the waiting time before a state transition in a continuous-time Markov chain?
Exponential distribution
Normal distribution
Binomial distribution
Poison distribution
The long-run proportion of time spent in a state is given by:
The initial state probability
The limiting probability
The transient probability
The transition probability
In a Markov chain, what happens if all states are transient?
The process eventually leaves all states and never returns
The chain reaches equilibrium
The transition probabilities become zero
The process becomes periodic
What does it mean for a state to be positively recurrent?
The expected return time is finite
The state is never visited
The state is visited only once
The transition probabilities sum to more than one
What is an absorbing state?
A state that can never be entered
A state that can never be left
A transient state
A state with equal transition probabilities
A transient state is a state that:
Is visited infinitely often
Is never left once entered
Has a probability of never being revisited
Has a self-transition probability of 1
What is the steady-state probability of a Markov chain?
The probability of reaching a state in one step
The probability distribution that remains unchanged over time
The probability of being in an absorbing state
The probability of being in the initial state
What is the probability of transitioning from state i to j in an absorbing Markov chain?
1
0
It depends on the transition probabilities
Equal for all states
What is the mean recurrence time of a state?
The time taken to reach the state for the first time
The expected time between consecutive visits to the state
The number of steps before the Markov chain terminates
The probability of transitioning to the state
What does the Perron-Frobenius theorem state about irreducible, aperiodic Markov chains?
They have a unique positive steady-state probability distribution
They have multiple steady-state distributions
They have only transient states
Their transition probabilities decrease over time
What is a recurrent state?
A state that is visited infinitely often
A state that is never visited
A state that is visited exactly once
A state that has no outgoing transitions
In a Markov chain, the transition probabilities depend on:
All previous states
Only the current state
Future states
External factors
What is a limiting state probability?
The probability of being in a state after infinite time
The probability of being in a state at time zero
The probability of transitioning between states
The probability of remaining in a state forever
If a Markov chain is irreducible and aperiodic, then:
It has an absorbing state
It has a unique stationary distribution
It cannot reach equilibrium
It is always deterministic
What is a transition probability matrix?
A matrix of all possible states
A matrix containing probabilities of state transitions
A matrix containing only zeros and ones
A matrix that determines the time index
If a Markov chain has a steady-state probability distribution, then:
The process is non-stationary
The state probabilities remain constant over time
The process must have an absorbing state
The transition probabilities change over time
In a continuous-time Markov chain, transitions occur:
At fixed time intervals
At random times governed by an exponential distribution
Only once per process
At deterministic time points
What does the law of large numbers imply for a Markov chain?
The relative frequency of visiting states converges to the steady-state probabilities
The state probabilities remain constant at all times
The process is always periodic
The transition probabilities become random
A communication class in a Markov chain is:
A set of states that can reach each other
A set of transient states
A set of periodic states
A set of absorbing states
What is a stochastic process?
A deterministic function of time
A collection of random variables indexed by time
A sequence of independent events
A process with only one possible outcome
