What is the role of an operating system?
To manage the hardware and resources
To provide software
To provide a nice looking interface
To make the computer easier to use
To provide a virtual machine
What is an intractable problem?
An unsolvable problem
A problem that can be solved
A problem that cannot be solved within a reasonable amount of time
A problem that is too big
A problem that is too abstract
How might we be able to solve an intractable problem?
The way we would solve any other problem
Using a heuristic approach
By ignoring some of the contraints and producing a non-optimal solution
By guessing randomly
Using an algorithm
What are the features of an embedded operating system?
Lower hardware requirements
High processing power
Limited or no user interface
Designed to run many different types of software
Designed to operate mostly on its own from within other hardware
Manages power consumption in battery-powered devices
What are the features of a desktop operating system?
Must be able to support a wide range of peripherals
Able to run on a wide range of hardware
Limited memory capacity
Supports a wide range of software
Must work on mobile devices
Must manage security
Customisable by the user
Hard to upgrade
Supports networking protocols
What is overflow?
Where a number is too large to be stored in the available number of bits
Where a number is too large
Where a number is too small to be stored in the available number of bits
Where a number is too small
Where a number overflows the boundary
Which of these situations might cause overflow?
Multiplying two numbers together
Dividing by a small number
Converting a number from one type to another
Adding two numbers
Dividing by zero
What does Third Normal Form mean?
No repeating groups of attributes
They don't rely on eachother
No non-key attribute depends on another non-key attribute
All attributes depend on a non-key attribute
They all depend on eachother
Why is putting a database in Third Normal Form important?
Minimise data duplication
Eliminate update anomalies
To save space
To keep the database from getting too big
When is an adjacency matrix appropriate?
When there are more edges than vertices
When there are a fewer edges than vertices
When there lots of nodes
When there are lots of edges
What are the properties of a tree?
Every node must be connected
There must be no cycles
It must be branched
It has cycles
Every node must be connected by more than one edge
No computing device can be more powerful than a Turing machine
If a Turing machine cannot solve a problem then it is still possible that it could be solved
What is the purpose of a subnet mask?
identifies which other computers are on the same segment
tells the computer where it is
shows which computers can have packets sent directly to them
identifies which computers are on a different segment
shows which computers must have packets sent to them via the router
What measures could be put in place to increase the security of a WiFi network?
Reduce the power of the transmitter
Check the MAC addresses trying to connect and only allow computers on a certain list to connect
Require a password to connect to the network
Send data unencrypted
Use a router
Allow all MAC addresses to connect
What is meant by overriding when writing programs that involve inheritance?
redefining methods that are defined in the parent class
using the same name for a method used in the parent class, but assigning new attributes to it
defining a new method
changing attributes of a class
using a method that is defined in the parent class