Chapter 14--simulations Flashcards
continuous or discrete sim? weather forecast
continuous
continuous or discrete sim? stock portfolio modeling
continuous
continuous or discrete sim? seismic exploration
discrete
continuous or discrete sim? hurricane tracking
continuous
continuous or discrete sim? predicting how many tellers a new back needs
discrete
continuous or discrete sim? `determining the number of waiting rooms for a doctor’s office
discrete
continuous or discrete sim? gas exploration
discrete
continuous or discrete sim? air-chemistry propogation
continuous
True/False. Simple systems are best suited to being simulated
false
True/False. Complex systems are dynamic, interactive, and complicated.
true
True/False. a model is an abstraction of a real system.
true
True/False. the representation of a model may be concrete or abstract.
true
True/False. in computer simulations, the models are concrete
false
True/False. the more characteristics or features represented in a model, the better.
false
True/False. continuous simulations are represented by entities, attributes, and events.
false. that’s actually discrete simulations
True/False. discrete event simulations are represented by partial differential equations.
false. that’s actually continuous simulations.
True/False. CAD stands for computer-aided drafting.
false. computer-aided design
True/False. a time-driven simulation can be thought of as a big loop that executes a set of rules for each value of the clock.
true
True/False. a model whose realization is within a computer program is an abstract model.
true
True/False. a concrete model can be realized within a computer program
false
True/False. Red is the specular highlight on a green plastic ball if the light source is red.
false
True/False. A commonly-used illumination model in computer graphics was developed in the 1970s.
true. 1971
True/False. Ambient light, diffuse reflection, and specular reflection are three components of a common shading model for computer graphics.
true
True/False. Computer graphics relies on research from other scientific fields for equations used in image creation.
true
What is the essence of constructing a model?
using the least possible number of all the elements of the thing being modeled to construct the model. using only those elements that are essential to modeling the behavior you are studying.
Name two types of simulations and distinguish between them.
discrete event and continuous. Discrete-event sims use objects, attributes, and events to model situations that have a clear beginning and end. Continuous sims use partial differential equations to model events without clear beginnings/endings.
what defines the interactions among entities in a discrete-event simulation?
the rules governing that define the results of the events in the simulation, and the entities that are chosen
what is the relationship between object-oriented design and model building?
in discrete-event simulation, object-oriented design is used by creating objects/entities and then determining the rules that define the results of the events.
Define the goal of a queuing system.
to utilize the servers as fully as possible while keeping the wait time to a minimum.
what are the 4 pieces of information needed to build a queuing system?
- the number of events and how they affect the system so we can determine the rules of entity interaction 2. the number of servers 3. the distribution of arrival times so we can determine if an entity enters the system 4. the expected service time so we can determine the duration of an event
What part does a random number generator play in queuing sims?
It helps model the element of chance in a simulation.
Distinguish between a FIFO queue and a priority queue.
a FIFO just serves the next customer in line. A priority queue prioritizes customers based on some attribute of the customer, like level of need.
What did SIMULA contribute to object-oriented programming methodology?
It contributed the concepts of classes, objects, inheritance, and polymorphism.
In general, meteorological models are based on the time-dependent equations of what fields?
thermodynamics and fluid dynamics.
Why is there more than 1 weather prediction model?
because each model makes certain assumptions, and none of the models’ sets of assumptions are completely correct. Each is wrong sometimes, and right sometimes. Multiple models are used simultaneously to reduce the chances of error.
What are specialized meteorological models, and how are they used?
they are for very specific situations, like the weather in a certain place, and they are used to predict the weather for applications like air pollution control, aircraft fuel usage prediction, and others.
What are seismic models used for?
to predict earthquakes, to help build more accurate models of the earth’s interior, and to help find geological deposits of minerals and fossil fuels.
What do simulations and spreadsheets have in common?
discrete-event simulations use objects/entities and attributes/fields.
How might you use a priority queue to simulate a stack?
You would set up the priority queue as the opposite of a FIFO queue, so that first priority automatically goes to the last object that entered the queue
How might you use a priority queue to simulate a FIFO queue?
You would set the priority to automatically go to the object that has been waiting in the queue the longest.
What is an award that Ivan Sutherland won, what is he most famous for, and what did this give rise to?
The Smithsonian Computer World Award, Sketchpad, which used a lightpen, and it was the first GUI, and this gave rise to CAD
What is Ivan Sutherland most proud of?
His 4 grandchildren
What award did Herbert Simon win?
The Turing award, for his work in human problem solving
What word did Herbert Simon coin, and what does it mean?
Satisfice
Define Pareto’s law.
In any group of entities, there are a trivial many and an important few
Define “illumination model”.
The simulation of light interacting at one point on am object.
Define “shading”.
The process of using an illumination model to determine the appearance of an entire object.
Name the three main components of shading.
Ambient light, diffuse reflections, and specular reflections.
What is ray tracing, and how is it different, and what is it different from?
Different from the older shading method. It uses the concept of lines drawn from the viewer location to the rendered object, and can display transparency and reflectivity, even simultaneously.
What is radiosity, and what does it handle well?
It is a shading technique that can handle color bleeding. It treats light as energy.
What is midpoint subdivision?
A fractal model that uses the dividing of triangles at their midpoints to model natural environments.
Define “erosion model”.
It is used to model how streams erode natural environments.
Define “catenary curve”.
How rope/cloth drapes between two suspended points. Used in rendering cloth in simulations
