Turing Machine by mark wood

Past Paper Questions

mark_wood — 2017-02-25 13:59:12 UTC

A Level AQA - Click here to download all of the Past Paper Questions from the AQA on Turing Machines

What is a Turing Machine?

mark_wood — 2017-02-25 14:01:07 UTC

Watch this video for a good explanation of a Turing Machine, which links in nicely to the 'Busy Beaver' problem (See Busy Beaver Video)

Busy Beaver Video

mark_wood — 2017-02-25 14:02:18 UTC

This video explains the Busy Beaver problem and how a Turing Machine is used to prove that this is an unsolvable problem

Turing Machine Explained

mark_wood — 2017-02-25 14:04:19 UTC

Another video to explain the Turing Machine

What would a Turing Machine look like?

mark_wood — 2017-02-25 14:04:55 UTC

This guy has made one so take a look

Turing Machine Summary

mark_wood — 2017-02-25 14:05:36 UTC

The Turing Machine is a theoretical/ abstract model / a concept to determine what problems are computable.

The Turing Machine is a Finite State Machine (FSM) that has an infinite memory/storage.

Every Turing Machine needs to be represented with:

A Start State
A Halting State
An Alphabet (usually 0,1,space)
Movement (the read/write head)
A Transition Function (what should be written at each cell and whether to move left or right)

Turing Machine Terminology

mark_wood — 2017-02-25 14:49:37 UTC

You could use this resource to revise definitions of the keywords associated with Turing Machines

Turing machines in detail

mark_wood — 2017-02-25 15:52:44 UTC

This document goes into great detail how the transition functions are defined and how failed computations are managed

Introduction to Turing Machines

mark_wood — 2017-02-25 15:56:41 UTC

This detailed written tutorial introduces Turing Machines as well as outlining the formal definition for a Turing Machine:

Transition Rules

mark_wood — 2017-02-25 16:15:38 UTC

δ (Current State, Input Symbol) = (Next State, Output Symbol, Movement)

e.g.
δ(S0, _ ) = (SH, 1, R)
δ(S0, 0 ) = (S0, 0, R)
δ(S0, 1 ) = (S1, 1, R)
δ(S1, _ ) = (SH, 0, R)
δ(S1, 0 ) = (S1, 0, R)
δ(S1, 1 ) = (S0, 1, R)

The above are the transition rules for an odd parity generator.

The Point

craig7659 — 2017-02-26 15:49:56 UTC

This webpage explains the components of a Turing Machine, gives some useful diagrams and then explains the point of them.

The Halting Problem

mark_wood — 2017-03-07 14:35:09 UTC

The Halting problem can be used to prove that some functions cannot be computed. This video although VERY annoying explains this as well as it can be explained. This is a concept that requires you to apply a deep understanding in order to gain knowledge on this topic. If you don't get it from this video then try and see if this one helps: https://goo.gl/8HSpx3

Create a Truing Machine

mark_wood — 2017-03-07 14:44:55 UTC

Here is a great resource from the University of Cambridge, which explains the Turing Machine concepts and then elaborates on how you might use a RaspberryPi to create one.

Universal Turing Machine (UTM)

mark_wood — 2017-03-07 14:47:18 UTC

This article introduces the idea of a Universal Turing Machine, which can be defined as:

> A Turing Machine that can execute the behaviour of any other Turing Machine

OR EVENT BETTER

> A UTM, U, is an interpreter that reads the description of any arbitrary Turing Machine M; and faithfully executes operations on data D precisely as M does; the description is written at the beginning of the tape, followed by D.

The Halting Problem in Python

mark_wood — 2019-10-26 12:43:07 UTC

Another Computerphile video, this time using Python to explain the concept of the Halting Problem