Big Idea 2 Flashcards
What is all digital data represented by at the lowest level?
bits (binary digits)
What can bits be grouped to represent?
Abstractions such as numbers, characters, and color.
What are number bases such as binary and hexadecimal used to represent?
They are used to represent and investigate digital data.
At the lowest levels of abstraction, digital data is represented in binary (base 2), represented using combinations of what to digits?
0 and 1.
Why is hexadecimal (base 16) used to represent digital data?
It is used because hexadecimal representation uses fewer digits than binary.
Can numbers be converted from any base to another base?
Yes.
What representation is used to model the infinite mathematical concept of a number?
A finite one.
What limitation in programming languages can result in overflow or other errors?
The fixed number of bits used to represent characters or integers which limits the range of integer values and mathematical operations.
What limitation in programming languages can result in round off and other errors?
The fixed number of bits used to represent real numbers (as floating-point numbers) which limits the range of floating-point values and mathematical operations.
What might a sequence of bits represent?
Instructions or data (different types of data can be used in different contexts).
What does the developing of an abstraction involve?
It involves the removing of details and generalizing functionality.
What does an abstraction accomplish?
An abstraction generalizes functionality with input parameters that allow software reuse.
What are five ways in which one could express an abstraction?
Constants, expressions statements, procedures, and libraries.
What do different programming languages offer?
Different levels of abstraction.
What do high-level programming languages typically offer?
They provide more abstractions for the programmer and make it easier for people to read and write a program.
What is code in a programming language usually translated into?
Code in another (lower level) language to be executed on a computer.
In an abstraction hierarchy, what level of abstractions are placed toward the top and what toward the bottom?
Higher levels of abstractions (more general concepts) are placed toward the top while lower level abstractions (more specific concepts) are placed toward the bottom.
What physical layers of computing hardware is used to process binary data?
Gates, chips, and components.
What is a logic gate?
A logic gate is a hardware abstraction that is modeled by a Boolean function.
What is a chip?
A chip is an abstraction composed of low-level components and circuits that preform a specific function.
What are the two ways in which a hardware component’s status can be?
It can be low level like a transistor or high level like a video card.
What is hardware made by?
Hardware is built using multiple levels of abstractions such as transistors, logic gates, chips, memory, motherboards, special purpose cards, and storage devices.
What are applications and systems made using?
Applications and systems are designed, enveloped, and analyzed using levels of hardware, software, and conceptual abstractions.
How can lower-level abstractions make higher-level abstractions?
By combining lower-level abstractions, one can make higher-level abstractions, such as short message services (SMS) or email messages, images, audio files, and videos.
What are models and simulations used to represent?
Models and simulations are simplified representations of more complex objects of phenomena.
What do models often omit?
Models often omit unnecessary features of the objects or phenomena that are being modeled.
What do simulations do? Why are they effective?
Simulations mimic real-world events without the cost or danger of building and testing the phenomena in the real world. Simulations are effective because they can facilitate extensive and rapid testing of models.
How do models and simulations assist in the hypothesis making process?
Models and simulations facilitate the formulation and refinement of hypothesis related to the objects of phenomena under consideration.
What are the two main results of simulation use?
The results of simulations may generate new knowledge and new hypothesis related to the phenomena being modeled. Simulations also allow hypotheses to be tested without constraints of the real world.
What three main things effect the time required for simulations?
Level of detail, quality of the models, and the software and hardware used. (DQS)
How can models be changed accurately to reflect the objects or phenomena being modeled?
Through rapid testing.
