Computer Science Exam 1

The first three chapters of CSC 115; none of the math is not present in this study set

number

a unit of an abstract mathematical system subject to the laws of arithmetic

integer

a natural number, a negative of a natural number, or zero

natural number

the number zero and any number obtained by repeatedly adding one to it

rational number

an integer or the quotient of two integers (division by zero excluded)

negative number

a value less than zero, with a sign opposite to its positive counterpart

T/F???? binary numbers are important in computing because a binary number can be converted into every other base

False

T/F???? binary numbers can be read off in hexadecimal but not in octal

False

T/F???? starting from left to right every grouping of four binary digits can be read as one hexadecimal digit

False

T/F???? a byte is made up six binary digits

False

T/F???? two hexadecimal digits cannot be stored in one byte

True

T/F???? reading octal digits off as binary produces the same result whether read from right to left or from left to right

True

distinguish between a natural number and a negative number

a natural number is 0 and any number that can be obtained by repeatedly adding 1 to it \n \n a negative number is less than 0 and opposite in sign of a natural number \n \n although we usually do not consider negative 0

distinguish between a natural number and a rational number

a rational number is an integer or the quotient of integer numbers \n \n a natural number is 0 and the positive integers

explain how base 2 and base 8 are related

because 8 is a power of 2, base 8 digits can be read off in binary and 3 base 2 digits can be read off in octal

explain how base 8 and base 16 are related

8 and 16 are both powers of 2

how many bits does a byte contain?

8

how many bytes are there in a 64 bit machine?

8

T/F lossless compression means the data can be retrieved without losing any of the original information

True

T/F a computer represents information in analog form

False

T/F a computer must use the binary number system to represent information

False

T/F a digital signal represents one of two values at any point in time

True

T/F four bits can be used to represent 32 unique things

False

T/F the signed magnitude representation of numbers has two representations for zero

True

T/F overflow occurs when the value that we compute cannot fit into the number of bits we have allocated for the result

True

T/F in the ASCII character set, no distinction is made between uppercase and lowercase letters

False

T/F the Unicode character set includes all of the characters in the ASCII character set

True

T/F keyword encoding replaces frequently used words with a single character

True

T/F run length encoding is very good at compressing English text

False

T/F Huffman encoding uses variable length binary strings to represent characters

True

T/F an audio signal is digitized by sampling it at regular intervals

True

T/F a CD stores audio information in a binary format

True

T/F the MP3 audio format discards information that cannot be heard by humans

True

T/F an RGB value represents a color using 3 numeric values

True

T/F indexed color increases the number of colors that can be used in an image, and thus increases the file size

False

T/F bitmap, GIF, and JPEG are all examples of raster graphics formats

True

T/F vector graphics represent images in terms of lines and geometric shapes

True

T/F a keyframe is used in temporal compression to represent the changes from one frame to another

False

why is data compression an important topic today

Data compression refers to reducing the amount of space needed to store a piece of data. Although computer storage is relatively cheep, as the amount of data keeps increasing rapidly the cost of storage is a factor. However, the most important reason for compressing data is that more and more we share data. The Web and its underlying networks have limitations on bandwidth that define the maximum number of bits or bytes that can be transmitted from one place to another in a fixed amount of time.

what is the difference between lossless and lossy data compression

A lossless data compression is one in which no information is lost. A lossy data compression is one in which some information may be lost.

why do computers have difficulty with analog information

Computers are discrete, finite machines. Analog information is continuous and infinite. Thus, computers cannot represent analog information directly; the analog information must be converted into a digital form.

is a clock with a sweeping second hand an analog device or a digital device

A sweeping second hand is an analog device. The motion of the hand is continuous.

what does it mean to digitize something

Digitizing is the act of breaking continuous information into discrete pieces so that we can represent each piece separately.

what is pulse code modulation

Pulse Code Modulation is a signal that jumps sharply between two extremes

how many things can be represented with four bits

16

how many things can be represented with five bits

32

how many things can be represented with six bits

64

how many things can be represented with seven bits

128

how many bits would be needed to represent a character set containing 45 characters?

6 bits. 63 distinct things can be represented in 6 bits; 31 distinct things can be represented in 5 bits. Therefore 6 bits must be used.

is a stereo speaker an analog device or a digital device

A stereo speaker is an analog device because it receives an analog representation of the sound wave from the stereo. The speaker receives the signal and causes a membrane to vibrate, which in turn vibrates the air (creating a sound wave), which in turn vibrates your eardrum.

what is an RGB value

RGB stands for Red, Green, and Blue. The RGB value is actually three numbers that indicate the relative contribution of each of these three colors

what does color depth indicate

Color depth is the amount of data used to represent a color; that is the number of bits used to represent each of the colors in the RGB value.

how does pixel resolution affect the visual impact of an image

If enough pixels are used (high resolution) and presented in the proper order side by side, the human eye can be fooled into thinking it's viewing a continuous picture.

explain temporal video compression

Temporal video compression uses the differences between frames as the basis for compression. A keyframe is stored in its entirety and then changes from that keyframe are stored.

what produces better sound quality, higher sampling rates or lower sampling rates

Higher sampling rates produce better sound quality

do vinyl record albums and compact disks record sound in the same way

No. Vinyl record albums use an analog representation, but compact discs store audio information digitally

what is resolution

Resolution refers to the number of pixels used to represent a picture

What French mathematician built and sold the first gear-driven mechanical machine that did addition and subtraction

Pascal

Who built the first mechanical machine that did addition, subtraction, multiplication, and division?

Leibniz

Who designed the first mechanical machine that included memory?

Babbage

Who was considered the first programmer?

Lovelace

Who proposed that a punched card be used for counting the census?

Hollerith

Who edited Babbage's work?

Lovelace

Who was Ada Lovelace's father?

Byron

Who would have been mentioned in the book the Code Breakers?

Turing

Who developed the concept of punched holes used in weaving cloth?

Jacquard

Who is associated with IBM?

Hollerith

3rd Generation Hardware

Circuit Boards

2nd Generation Hardware

Transistor

2nd Generation Hardware

Magnetic Core Memory

1st Generation Hardware

Card input/output

4th Generation Hardware

Parallel Computing

1st Generation Hardware

Magnetic Drum

1st Generation Hardware

Magnetic Tape Drives

3rd Generation Hardware

Integrated Circuits

4th Generation Hardware

Personal Computer

1st Generation Hardware

Vacuum tube

4th Generation Hardware

Large scale integration

2nd Generation Hardware

Magnetic Disc

4th Generation Hardware

Networking

1st Generation Software

Assemblers

2nd Generation Software

FORTRAN

3rd Generation Software

Operating Systems

4th Generation Software

Structured Programming

3rd Generation Software

Time sharing

5th Generation Software

HTML(for Web)

2nd Generation Software

Loaders

4th Generation Software

Spreadsheets

4th Generation Software

Word processors

2nd Generation Software

Lisp

4th Generation Software

PC-DOS

3rd Generation Software

Loaders/Linkers bundled into Operating System

5th Generation Software

Java

3rd Generation Software

SPSS

4th Generation Software

C++

What do we mean by the statement that 'the 1980s and 1990s must be characterized by the changing profile of the user'?

The changing profile of the user represents a transition from capacity of computer tools. The users of the pre-80s 1st, 2nd, and 3rd generations were solely mathematicians, engineers, systems/applications programmers. With the advent of structured programming and large-scale integration, software and hardware improved creating a broader user audience. Examples of tools used by these users include: spreadsheets, word processing, and data-base management systems.

Why was Mosaic important?

Mosaic was important because it was the first graphics-capable browser

Discuss the browser wars.

The browser wars surrounded Netscape Navigator (Mosaic derived) and Microsoft's Internet Explorer competing for market dominance. When Microsoft bundled IE with its Windows OS, this made it a winner. This bundling led to a 2001 lawsuit against Microsoft by the US government requiring Microsoft to be more open to its competitors. Netscape was purchased by American Online in 1997. By 2007, AOL stopped supporting Netscape - but along the way, Mozilla Firefox absorbed features of Netscape in November 2004. By 2014, Mozilla Firefox captured 25% of the browser market.

Describe how the Web changed after 2002.

Around 2002, the Web changed as social networking sites and online blogging are introduced. These user-generated and -edited content examples include Facebook, Twitter, and Wikipedia

Of the predictions listed in this chapter on page 25, what do you consider the biggest error in judgment? Explain.

This 1982 IBM assessment is the biggest error in judgment: $100 million is way too much to pay for Microsoft. Microsoft is now worth about 63 billion according to Forbes. Also, Microsoft outcompetes Netscape and is so competitive that the U.S. Government sues them. These are indicators of how valuable Microsoft has become since IBM's early 4th-generation comment.

Name the four areas in which the practitioner must be skilled.

Algorithmic thinking, Representation, Programming, Design