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91 Terms
Which option is most appropriate for a specially formatted ASCII report?
A random sampling rule
axis square
plot3 only
Low-level output using fprintf
Low-level output using fprintf
A LineSpec may specify which combination?
Input, output, and error estimate
Mean, variance, and distribution
Color, line type, and marker
Filename, directory, and extension
Color, line type, and marker
If 7,850 of 10,000 random points fall inside a unit quarter circle, the estimate of pi is:
0.785
31.4
3.14
7.85
3.14
What does error estimation describe in a Monte Carlo study?
Only computer storage space
Statistical error as a function of run count and other parameters
The exact deterministic answer
The spelling errors in source code
Statistical error as a function of run count and other parameters
Why must each line have the same number of values for the basic load approach?
Different rows would change the filename
MATLAB requires every file to be a square
The data must form a rectangular matrix
The command reads only strings
The data must form a rectangular matrix
Why is a grid helpful in a 3D visualization?
It converts the plot to ASCII
It generates random samples
It calculates simulation error
It improves spatial interpretation of plotted values
It improves spatial interpretation of plotted values
Sensitivity analysis reveals that one input has almost no effect on output. A reasonable model-improvement decision is to:
Increase its complexity automatically
Stop validating the model
Consider simplifying its representation
Delete all influential inputs
Consider simplifying its representation
Why does Monte Carlo simulation produce a statistical description of model output?
It computes only one exact answer
Each run uses randomly sampled input values
It eliminates all model uncertainty
Every run uses identical inputs
Each run uses randomly sampled input values
Which MATLAB function is another way to export a numeric array as a delimited file?
dlmwrite
xlabel
input
bar3
dlmwrite
Which sequence correctly creates a basic 2D function plot?
Use load without defining data
Call zlabel, then save the file
Define x, compute y=f(x), then call plot(x,y)
Call title, then define x only
Define x, compute y=f(x), then call plot(x,y)
Which command labels the horizontal axis?
ylabel
legend
zlabel
xlabel
xlabel
Why identify the inputs with the greatest influence on output?
To guarantee all inputs are equally important
To prioritize research and model refinement
To eliminate the model output
To avoid defining input bounds
To prioritize research and model refinement
Which statement accurately describes a key limitation of Monte Carlo results?
They cannot be generated by computers
They approximate true values rather than guarantee exact values
They require no sampling
They are always deterministic constants
They approximate true values rather than guarantee exact values
What does axis equal do?
Creates a square data matrix
Adds equal labels to every point
Forces x and y data to be identical
Uses equal scale factors on both axes
Uses equal scale factors on both axes
When save writes a character array to an ASCII file, it writes:
A probability distribution
ASCII equivalents of the characters
Only the variable name
A 3D surface
ASCII equivalents of the characters
Which component prescribes how values are drawn from probability distributions?
File extension
Plot title
Scoring method
Sampling rule
Sampling rule
Which function labels the third axis of a 3D plot?
grid
title
zlabel
ylabel
zlabel
Which MATLAB option writes a numeric array as delimited ASCII data?
plot3
menu
zlabel
save with the -ascii qualifier
save with the -ascii qualifier
Derivative-based sensitivity analysis is most defensible without wider exploration when the system is:
Highly nonlinear with thresholds
Discontinuous everywhere
Undefined
Linear
Linear
What occurs immediately after random inputs are generated in the four-step Monte Carlo process?
The final result is reported without computation
The model is deleted
All distributions are replaced by constants
A deterministic computation is performed using them
A deterministic computation is performed using them
Which function plots points using x, y, and z coordinate vectors?
plot
dlmwrite
bar
plot3
plot3
Which component combines individual-run results into a final result?
Scoring method
Input prompt
Axis scaling
Random-number seed only
Scoring method
Which statement best defines sensitivity analysis?
Selecting a plot marker color
Saving an array as ASCII
Studying how output uncertainty is assigned to input uncertainty sources
Computing only the average input
Studying how output uncertainty is assigned to input uncertainty sources
Which field is identified as an application area of Monte Carlo simulation?
Keyboard configuration only
Finance and project management
Document pagination only
Grammar correction only
Finance and project management
Which command reads a compatible numeric text file into MATLAB?
title
hold on
legend
load
load
What is the purpose of hold on when adding another curve?
Close the active figure
Preserve the current axes and plot additional data
Rotate a 3D plot
Overwrite the data file
Preserve the current axes and plot additional data
Which problem is especially suitable for Monte Carlo simulation?
Displaying one known constant
Formatting a fixed text file
Renaming a MATLAB variable
Estimating risk when several inputs are uncertain
Estimating risk when several inputs are uncertain
For a nonlinear model, which plan best addresses the local nature of derivatives?
Ignore input uncertainty
Use a derivative at one point as globally conclusive
Evaluate sensitivity at multiple relevant operating points
Run only the deterministic mean case
Evaluate sensitivity at multiple relevant operating points
What does a MATLAB diary file record?
Keystrokes and resulting text output
Only probability densities
Compiled C++ code exclusively
Only 3D coordinates
Keystrokes and resulting text output
Which command adds a title to a plot?
load
plot3
dlmwrite
title
title
Before sampling an uncertain input, what must the modeler define?
Its exact future value
A queue discipline
A 3D viewing angle
Its probability distribution
Its probability distribution
What is the final step of the four-step Monte Carlo process?
Convert every output to text
Aggregate individual-run results
Remove random values
Choose only the largest input
Aggregate individual-run results
Which command identifies plotted data series by name?
legend
load
axis square
xlabel
legend
Why does the geometric estimate of pi generally improve with more points?
Randomness disappears completely
The true value of pi changes
The square becomes smaller
The sampled area proportion tends to stabilize
The sampled area proportion tends to stabilize
Monte Carlo simulation originated during the 1940s in work associated with:
MATLAB file export
Airport queue design
Los Alamos National Laboratory
Spreadsheet plotting
Los Alamos National Laboratory
In the geometric estimation of pi, random points are generated within:
A text file containing characters
A queue containing servers
A square containing a quarter-circle arc
A three-dimensional bar chart
A square containing a quarter-circle arc
Why are many simulation runs often required?
To remove the need for distributions
To turn an approximation into symbolic algebra
To guarantee every input is identical
To reduce sampling uncertainty and stabilize estimates
To reduce sampling uncertainty and stabilize estimates
What happens when save writes to an existing file as described in the module?
The file is overwritten from the beginning
The old file becomes a plot
New data are always appended
Only the filename changes
The file is overwritten from the beginning
Which is an advantage of Monte Carlo simulation?
It requires no input model
It always returns an exact closed form
It can provide approximate solutions to difficult numerical problems
It needs only one sample
It can provide approximate solutions to difficult numerical problems
Which function creates a three-dimensional bar chart?
bar3
plot
stem
bar
bar3
What is a major limitation of derivative-based sensitivity analysis?
It always evaluates the whole input space
Its conclusions are local to the point where derivatives are computed
It is valid only when no equations exist
It cannot be computed efficiently
Its conclusions are local to the point where derivatives are computed
In the Monte Carlo estimate of pi, which ratio is central to the calculation?
Points inside the quarter circle divided by total points in the square
Circle diameter divided by random seed
Points outside the square divided by all points
Number of plots divided by number of files
Points inside the quarter circle divided by total points in the square
A data file has rows with unequal numbers of numeric values. Based on the module, what is the best conclusion?
Basic load is not suitable without restructuring the data
plot3 should be used to read it
save -ascii will repair it during reading
load will automatically invent missing values
Basic load is not suitable without restructuring the data
Which MATLAB function produces a two-dimensional bar chart?
zlabel
bar3
bar
plot3
bar
A manager uses only 10 runs and obtains unstable estimates. What is the best response?
Increase the number of runs and examine convergence
Delete the error estimate
Report the first run only
Replace all random inputs with zero
Increase the number of runs and examine convergence
A Monte Carlo script must save run outputs, reload them, and inspect their distribution visually. Which workflow best integrates the module skills?
Use zlabel to generate random numbers
Save the numeric results, load the rectangular data, then create labeled 2D or 3D plots
Use axis square instead of performing simulation runs
Create a title, delete the outputs, then run one deterministic case
Save the numeric results, load the rectangular data, then create labeled 2D or 3D plots
What does axis square do?
Makes the plot box square
Saves the figure as ASCII
Converts a 2D plot to 3D
Makes every data value equal
Makes the plot box square
Why might automated debugging fail to find an important model error?
It only performs optimization
Semantic errors can be difficult to detect automatically
It always validates the real system
It cannot find syntax errors
Semantic errors can be difficult to detect automatically
Which is a major advantage of formal models?
They require no mathematical knowledge
They support unambiguous representation and rigorous analysis
They eliminate the need for requirements
They are always faster and easier to design
They support unambiguous representation and rigorous analysis
A model connects components directionally using equations and related variables. Which type best fits?
Face-validation model
Spatial model
Concept map only
Functional model
Functional model
A project team needs a one-page overview for stakeholders before detailed modeling. Which product is best?
An objective function only
A conceptual model
A code debugger
A complete formal model
A conceptual model
Why is Simulink integration with MATLAB valuable?
It removes the need for simulation
MATLAB algorithms can be incorporated and results exported for further analysis
It limits models to one block
It prevents all use of MATLAB code
MATLAB algorithms can be incorporated and results exported for further analysis
Which notation is identified as standardized, semiformal, object-oriented, and graphical?
FIFO
ASCII
LCG
UML
UML
What is face validation?
Formal proof that all outputs are exact
Automated calculation of syntax errors
Subjective assessment of model output by knowledgeable experts
A stress test at maximum input only
Subjective assessment of model output by knowledgeable experts
What does model validation primarily ask?
Is the model a sufficiently close approximation of the target system for its purpose?
Are all UML arrows labeled?
Is every input at a boundary?
Does the code compile with no syntax errors?
Is the model a sufficiently close approximation of the target system for its purpose?
In a concept map, nodes represent:
Objective-function coefficients only
Simulation run times only
Only mathematical errors
System concepts or elements
System concepts or elements
Which question should a useful conceptual model help answer?
What is the exact optimum of every objective?
Which compiler produced the model?
What is the system and what does it do?
What is every line of executable code?
What is the system and what does it do?
Which UML tool is most appropriate for showing interactions between objects over time?
Use case only
Conceptual paragraph
Sequence diagram
Class diagram
Sequence diagram
Which model type in Fishwick’s perspective is primarily state-event focused?
Declarative model
Functional model
Spatial model
Constraint model
Declarative model
A model represents rooms as elements and tracks entities inside them. It is best classified as:
Spatial
Declarative
Linear programming
Functional only
Spatial
What is the first stated step in an OR study?
Formulate the problem
Perform face validation
Select a UML diagram
Run Simulink immediately
Formulate the problem
A model matches real output well but contains incorrectly implemented requirements. Which conclusion is best?
The conceptual model is irrelevant
Validation evidence does not replace verification
The model is formally proven
The model needs no review
Validation evidence does not replace verification
A hydraulic network emphasizes physical balancing relationships more than connection direction. Which model type is most appropriate?
Declarative model
Conceptual picture
Spatial model
Constraint model
Constraint model
Which UML tool focuses on how users or external actors use a system?
Statechart only
Use case
Constraint equation
Sequence diagram only
Use case
A model runs without errors but produces unrealistic behavior. Which conclusion is strongest?
It is validated but not executable
It may be verified but not validated
It is automatically optimal
It requires only a new filename
It may be verified but not validated
What does an objective function in linear programming specify?
Whether a concept map is informal
Which UML actor starts the system
How Simulink draws a block
What quantity should be maximized or minimized
What quantity should be maximized or minimized
What does Simulink provide for dynamic-system modeling?
Only a text editor with no solver
Only UML diagrams
Only spreadsheet export
A graphical editor, block libraries, and solvers
A graphical editor, block libraries, and solvers
A city model treats geographic zones as elements. Which Fishwick model type is being used?
Spatial model
Functional model
Declarative model
Constraint model
Spatial model
Which other stochastic OR method is identified?
ASCII export
Sequence diagramming
Formal debugging
Queuing theory
Queuing theory
A system has physical-flow, software-control, and spatial phases. Which strategy is best?
Use validation instead of modeling
Use one informal picture for all analyses
Connect suitable model types in a hybrid model
Ignore phases that require different representations
Connect suitable model types in a hybrid model
Which method directly supports objective validation when target-system output exists?
Renaming model blocks
Drawing a concept map
Manual syntax review only
Statistical testing of differences between model and target outputs
Statistical testing of differences between model and target outputs
Which of the following is a stochastic OR method mentioned in the module?
UML class modeling
Manual code review
Markov chains
Linear programming only
Markov chains
Which UML tool is most appropriate for representing system or software classes and their relationships?
Activity diagram
Class diagram
Statechart only
Stress test
Class diagram
What do labels on concept-map arcs describe?
The model’s final profit
The nature of the interaction
The syntax of a solver
The size of the software file
The nature of the interaction
Which UML tool best captures workflows or sequences of activities?
Class diagram
Linear objective function
Use case title
Activity diagram
Activity diagram
What is the primary goal of operations research?
Remove mathematical models from decisions
Validate software syntax
Create only informal pictures
Optimize system performance to support decisions such as maximizing profit or minimizing cost
Optimize system performance to support decisions such as maximizing profit or minimizing cost
A team wants to compare several controller designs before building hardware. Which tool use best matches the module?
Use face validation without simulation
Run a queueing model in a class diagram
Model and simulate the alternatives in Simulink
Develop only a conceptual paragraph
Model and simulate the alternatives in Simulink
When the target system does not yet exist, which validation method may be used?
Linear programming without constraints
Expert examination or comparison with a similar system
Automated syntax debugging only
Deleting the output equations
Expert examination or comparison with a similar system
What is the simplest form of a conceptual model identified in the module?
A picture of the system
A linear-programming tableau
A stress-test report
A full Simulink solver
A picture of the system
What is the value of a manual code review?
It replaces the conceptual model
Peers can critique the implementation and identify problems
It computes an OR optimum
It automatically proves model validity
Peers can critique the implementation and identify problems
What is a modeling formalism?
A methodology with precise rules for modeling and simulation
An entirely unstructured sketch
A list of hardware devices
A validation opinion only
A methodology with precise rules for modeling and simulation
What trade-off characterizes semiformal modeling?
Exact optimization with no model
No notation and no analysis
Maximum rigor with no usability
Greater ease of use with less unambiguity but some analytic capability
Greater ease of use with less unambiguity but some analytic capability
A team’s concept map has arrows but no labels. What important information is missing?
The meaning of each interaction
The use of rectangles or circles
The presence of a graph
The existence of system elements
The meaning of each interaction
What does model verification primarily ask?
Is the business profit maximal?
Is UML a formalism?
Is the model close enough to the real target system?
Was the conceptual model translated correctly into the executable model?
Was the conceptual model translated correctly into the executable model?
After formulating an OR problem, what comes next?
Remove constraints
Develop a mathematical model of the system
Publish the final decision
Perform hardware deployment
Develop a mathematical model of the system
What role do inequality constraints play in linear programming?
They limit feasible values of system variables
They identify syntax errors
They create random outputs
They label concept-map arcs
They limit feasible values of system variables
A safety-critical controller requires precise analysis of properties, limits, and constraints. Which approach is most defensible?
Formal modeling
An unlabeled picture only
Face validation without a model
A purely informal paragraph
Formal modeling
Why are hybrid models valuable for complex real-world systems?
They require no connections among submodels
They eliminate all implementation complexity
They force every phase to use one notation
They support multiple perspectives and a wider variety of questions
They support multiple perspectives and a wider variety of questions
What is the primary purpose of a conceptual model?
Prove mathematical optimality
Provide executable code with no ambiguity
Replace verification and validation
Quickly communicate the system’s main qualities and capabilities
Quickly communicate the system’s main qualities and capabilities
A model is run with minimum and maximum boundary inputs. This is a:
Class diagram
Face validation
Model stress test
Concept map
Model stress test
Which UML tool is most suitable for describing how a system changes among states?
Code review
Use case
Class diagram
Statechart
Statechart