ch. 14 Computers in Medical Imaging
worldwide web
1990, Tim Berners-Lee invents the ____, which has profoundly connected us and shrunk our planet communications-wise.
BASIC
Microsoft developed ___ into a powerful programming language that can be used for commercial applications and for quick, single-use programs.
random access
RAM; means data can be stored or accessed at random from anywhere in main memory in approximately equal amounts of time regardless of where the data are located.
read-only memory
ROM; contains information supplied by the manufacturer, called firmware, that cannot be written on or erased.
bus
a computers processor consists of a control unit and an arithmetic/logic unit. these two components and all other components are connected by an electrical conductor called a ____.
chips
a tiny piece of semiconductor material usually silicon.
voice-recognition systems
add a microphone and an audio sound card to a computer and can convert speech into digital format.
FORTRAN
also known as formula translation. the oldest language for scientific, engineering, and mathematical problems.
compilers and interpreters
are computer programs that translate and application program from its high-level language, such as Java, BASIC, C++, or Pascal, into a form that is suitable for the assembler or into a form that is accepted directly by the computer.
common output devices
are display screen and printers. other devices include plotters, multifunction devices, and audio output devices.
digital images
are made of discrete picture elements, pixels, arranged in a matrix.
visual programming languages
are more recent languages, and they are under continuing development. they are designed specifically for the creation of Windows applications.
DRAM chips
are more widely used but SRAM chips are faster.
computer programs
are the software of the computer. the sequence of instructions developed by a software programmer is called a computer program.
byte
bits are combined into groups of 8 bits called a ___. it represents one character, digit, or other value.
dumb terminal
cannot do any processing on its own; it is used only to input data or receive data from a main or host computer.
sensors
collect data directly from the environment and transmit them to a computer. they are sued to detect things such as wind speed or temperature.
application programs
computer programs that are written by a computer manufacturer, by a software manufacturer, or by the users themselves to guide the computer to perform a specific task are called ___.
binary number system
computers operate on the simplest number system of all. counting in the binary number system starts with 0 to 1 and then counts over again. 0 is 0 and 1 is 1.
assemblers, compilers, and interpreters
computers ultimately understand only 0s and 1s. to relieve humans from the task of writing programs in this form, other programs called ___ have been written.
output hardware
consists of devices that translate computer information into a form that humans can understand
software
consists of the computer programs that tell the hardware what to do and how to store and manipulate data.
data files
contain data, not programs
image files
contain digital images
audio files
contain digitized sound
video files
contain digitized video images.
program files
contain software instructions
C++
contains the entire C language, as well as many additions designed to support object-oriented programming
tracks
data are recorded on a CD in rings called __, which are invisible, closed concentric rings.
bit
describes the smallest unit of measure, a binary digit 0 or 1.
communications or telecommunications
describes the transfer of data from a sender to a receiver across a distance.
human biology input devices
detect specific movements and characteristics of the human body.
ink-jet printers
form images with little dots. they electrically charge small drops of ink that are then sprayed onto the page. they are quieter and less expensive and can also print in color.
intelligent terminal
has built-in processing capability and RAM but does not have its own storage capacity.
laser printers
have built-in RAM chips to store output from the computer; ROM chips that store fonts; and their own small, dedicated processor
RAID systems
have greater reliability because if one disc drive fails, others can take over. it is a redundant array of independent disc system that consists of two or more disc dives in a single cabinet that collectively act as a single storage system.
toner
images are created with dots on a drum, are treated with a magnetically charged ink-like substance called ___, and then are transferred from drum to paper.
central processing unit
in a computer is the primary element that allows the computer to manipulate data and carry out software instructions. it contains a control unit, an arithmetic unit, and sometimes memory.
bit
in computer language, a single binary digit, 0 or 1, and it is called a ___.
operations
include input processing, memory, storage, output, and communications.
source data entry devices
include scanners, fax machines, imaging systems, audio and video devices, electrons cameras, voice-recognition systems, sensors, and biologic input devices.
input hardware
includes keyboards, mice, trackballs, touchpads, and source data entry devices. it converts data into a form that the computer can use.
terabyte
is 1024 gigabytes and approximately 1 thousand billion bytes and higher capacity hard drives are often measure in terabytes.
assembler
is a computer program that recognizes symbolic instructions such as subtract, load, and print, and translates them into the corresponding binary code.
Pascal
is a high-level, general purpose programming language that was developed in 1971 by Nicklaus Wirth of the Federal Institute of Technology.
storage
is an archival form of memory
transistor
is an electronic switch that alternately allows or does not allow electronic signals to pass. it made possible the development of the stored program computer and thus the continuing explosion in computer science.
terminal
is an input/output device that uses a keyboard for input and a display screen for output.
gigabyte
is approximately 1 billion bytes and is used to measure the capacity of hard disc drives and sometimes RAM memory
megabyte
is approximately 1 million bytes
half a byte
is called a nibble and two words is called a chomp
C
is considered by many to be the first modern programmer's language.
computer memory
is distinguished from storage by its function. whereas memory is more active, storage is more archival.
hardware
is everything about the computer that is visible; the physical components of the system that include the various input and output devices.
digital
is now almost synonymous with computer.
secondary memory
is required in the form of compact discs, digital video discs, hard disc drives, and solid-state storage devices. It functions similarly to a filing cabinet--you store information there until you need to retrieve it.
operating system
is that series of instructions that organizes the course of data through the computer to the solution of a particular problem.
CD drive
is the device that holds, spins, reads data from, and writes data to a CD.
Pascal
is the most popular programming language for teaching programming concepts, partly because its syntax is relatively easy to learn and closely resembles that of the English language in usage.
soft copy
is the term that refers to the output seen on a display screen
teleradiology
is the transfer of images and patient reports to remote sites
power of 2 notation
is used in radiologic imaging to describe image size, image dynamic range (shades of gray), and image storage capacity.
electric current, radiofrequency, or light
is used to transfer data through a physical medium, which may be a cable, a wire, or even the atmosphere (wire-less).
systems software and applications programs
it is useful to distinguish two classifications of computer programs:
secondary storage devices
most common types are CDs, DVDs, Blu-ray discs, hard discs, and flash drives.
macros
most spreadsheet and word processing applications offer built-in programming commands called ____. they are used to carry out user-defined functions or a series of functions in the application.
Excel
one application that offers a very good library of macro commands is ___, a spreadsheet.
COBOL
one high-level, procedure-oriented language designed for coding business data processing problems is ___.
mother board
or system board is the main circuit board in a system unit. this board contains the microprocessor, any coprocessor chips, RAM chips, ROM chips, other types of memory, and expansion slots, which allow additional circuit boards to be added.
algorithms
problems that can be expressed in terms of formulas and equations are sometimes called ___. it's a step by step process used to solve a problem.
analog
refers to a continuously varying quantity
computer
refers to any general purpose stored program electronic digital computer.
kilobyte
represents 1024 bytes
flash drive
sometimes called a jump drive or jump stick, is the newest of the small portable memory devices. it has a capacity of sever GB; it connects through the USB port and transfers data rapidly.
registers
special high-speed circuitry areas called ___ are found in the control unit and the ALU. they are contained in the processor that hold information that will be used immediately.
control unit
tells the computer how to carry out software instructions, which direct the hardware to perform a task. it is part of the central processing unit that is directly connected with additional primary memory and various input/output devices.
operating system
the computer program most closely related to the system hardware is the __.
processor
the electronic circuitry that does the actual computation and the memory that supports this together are called the ____.
UNIVAC
the first commercially successful general-purpose, stored program electronic digital computer.
electronic computer
the first general-purpose ____ was developed in 1946 called ENIAC (electronic numerical integrator and calculator), it contained more than 18,000 vacuum tubes that failed at an average rate of one every 7 minutes.
transmission speed
the speed at which a modem transmits data, is measure in bits per second or kilobits per second.
internal system clock
the speed of tasks are determined by an ____. the faster the clock, the faster the processing. microcomputer processing speeds usually are defined in megahertz.
file
the word ___ is used to refer to a collection of data or information that is treated as a unit by the computer.
two types of nonimpact printers
they are used with microcomputers are laser printers and ink-jet printers
binary digits
to encode is to translate from ordinary characters to computer-compatible characters
scanners
translate images of text, drawings, or photographs into a digital format recognizable by the computer.
all computer languages
translate what the user inputs into a series of 1s and 0s that the computer can understand. the computer can accept and report alphabetic characters and numeric information in the decimal system, it operates in the binary system.
audio input devices
translates analog sound into digital format.
integrated services digital network
transmits over regular phone lines up to five times faster than basic modems.
third generation computers
used integrated circuits which consist of many transistors and other electronic elements fused onto a chip in 1964.
digital system
uses only two values that vary discretely though coding.
RAM capacity
usually is expressed as megabytes, gigabytes, or terabytes. referring to millions, billions, or trillions of characters stored.
fourth generation computers
was an extension of the third generation and incorporated large-scale integration. this has now been replaced by very large scale integration, which places millions of circuit elements on a chip that measures less than 1cm, in 1975.
second generation computers
were based on individually packaged transistors in 1958
first generation computers
were vacuum devices in 1939-1958.
bootstrap
when the computer is first turned on, nothing is in its temporary memory except a program called a ___. this loads the operating system into primary memory, which in turn controls all subsequent operations.
barcode readers
which translate the vertical black and white striped codes on retail products into digital form, are a type of scanner.
