OCR A level computer science 2.2.2

What is pattern recognition?

A computational problem used in hundreds of different of applications such as:

- medical diagnosis

- speed cameras

- detecting a dangerous overcrowded platform on an underground railway

- spam email filtering

Methods of problem solving

- Trial and error

- Enumeration

- simulation

- Theoretical approach

- creative solution

Enumeration

Listing out all possible options or cases one by one

Simulation problems

Process of designing a model of a real system in order to understand the behaviour of the system and to evaluate various strategies for its operation

Simulation applications include

- Financial risk analysis

- Amusement park rides

- Population predictions

- Managing inventory systems

- Queueing problems

Simulation of queueing systems

A queueing system is described by:

- the arrival rate

- time between arrivals

- number of servers

- service time

divide and conquer

- A very efficient strategy

- involves finding a solution to a sequence of smaller, related problems until the instance is small enough to be solved directly

What is backtracking?

Where you go some way along one route and then backtrack to see if there is a better route

What are heuristic methods used for?

Rapidly finding a solution that is 'good enough', even though it might not be the optimal solution

What applications are heuristic methods used in?

- transportation

- AI

- DNA analysis

- virus checking

Examples of heutristic methods

- 'rules of thumb'

- educated guesses

- intuitive judgement

- common sense

What is data mining?

The process of collecting and then analysing huge amounts of data

Applications of data mining

- increasing response rates to marketing campaigns by being able to target them more accurately to the needs of each customer

- Detecting fraud

- finding connections between seemingly unconnected events

Big Data

Often used in connection with data mining,

Huge amounts of data are collected and stored.

The 3V's for Big data

- Volume

- Variety

- Velocity

Performance of sorting algorithms

- The bubble sort is the slowest of the well-known algorithms

- The quicksort is very fast for a large number of items

What is pipelining?

An implementation technique in which multiple instructions are overlapped in execution, much like assembly line.