I asked a question from my cousin and said make it simple these terms
baffle me and make it plain as mud. Eric's plain as mud Email to Dorothy
claire
----- Original Message -----
From: "Eric Archer" <archer4491@xxxxxxxxxxx>
To: "Claire Ingram-Gorban" <user@xxxxxxxxxxxxxxxxxxxxxx>
Sent: Thursday, October 06, 2005 9:57 PM
Subject: *** SPAM *** RE Definitions Of Computing Terms etc
Dear Claire
Here as promised are some well known, but little understood computing terms:
Firstly there is the term ALGORITHM:
"In mathematics and computer science an algorithm (the word is derived from the name of the Persian mathematician Al-Khwarizmi) is a finite set of well-defined instructions for accomplishing some task which, given an initial state, will terminate in a corresponding recognizable end-state (contrast with heuristic). The concept of an algorithm is often illustrated by the example of a recipe, although many algorithms are much more complex; algorithms often have steps that repeat (iterate) or require decisions (such as logic or comparison) until the task is completed. Correctly performing an algorithm will not solve a problem if the algorithm is flawed or not appropriate to the problem. For example, a hypothetical algorithm for making a potato salad will fail if there are no potatoes present, even if all the motions of preparing the salad are performed as if the potatoes were there.
Different algorithms may complete the same task with a different set of instructions in more or less time, space, or effort than others. For example, given two different recipes for making potato salad, one may have peel the potato before boiling the potato while the other presents the steps in the reverse order, yet they both call for these steps to be repeated for all potatoes and end when the potato salad is ready to be eaten.
Certain countries, such as the USA, controversially allow some algorithms to be patented, provided a physical embodiment is possible (for example, a multiplication algorithm may be embodied in the arithmetic unit of a microprocessor)."
Algorithms are often associated with FLOW CHARTS:
A Flow Chart is a diagrammatic representation of all the processes & decisions required to produce an end result.
So if the flow chart shows all the necessary decisions & data input required to produce a result it is a visual & of course logical way to show this. Each little box or action being represented by an algorithm.
Now to our next term which is the word HEURISTIC:
"Heuristic is the art and science of discovery and invention. The word comes from the same Greek root as "eureka": εὑρισκω, which means "I find". A heuristic is a way of directing your attention fruitfully. The term was introduced by Pappus of Alexandria in the 4th century.
The mathematician George Polya popularized heuristic in the twentieth century in his book 'How to Solve It'. He learned mathematical proofs as a student, but didn't know how mathematicians think of proofs, nor was this taught. 'How to Solve It' is a collection of ideas about heuristic that he taught to math students: ways of looking at problems and casting about for solutions.
Some commonplace heuristics, all from 'How to Solve It' are:
* If you are having difficulty understanding a problem, try drawing a picture. * If you can't find a solution, try assuming that you have a solution and seeing what you can derive from that ("working backwards"). * If the problem is abstract, try examining a concrete example. * Try solving a more general problem first (the "inventor's paradox": the more ambitious plan may have more chances of success).
Grammatical note: The name of the topic is heuristic (not "heuristics"), a particular technique of directing your attention toward discovery is a heuristic, two or more of these are heuristics, and the adjective for "pertaining to how something is discovered" is heuristic."
Now I'm sure that was as clear as mud, but listen to the definitions again & perhaps you'll begin to realise that they are all about "means to an end". That is an algorithm is avery specific computing piece of software which is in a sense a self-contained miniature program. When this is joined up to other algorithms a network or pattern of steps is produced to enable decisions based on variable information being treated logically.
Whereas HEURISTIC is how to set out those logical steps in the first place in order to produce a result from a series of repeated or iterative mini-decision making programs.
Well to end this long & quite difficult journey into the concepts & means whereby complex instructions are made into "bite-sized" chunks that a machine such as a computer can deal with, I'll briefly mention the mathematics of BINARY:
"The binary numeral system represents numeric values using two symbols, typically 0 and 1. More specifically, binary is a positional notation with a radix of two. In other words a binary number can only contain a '0' or a '1' in each of the places along its length. It's usually read from the digit on the far right of the number to the left.
It's essentially increasing by the power of 2 to the 0,1,2,3 etc ie 2 to the 0 = 1, 2 to 1 = 2, 2 to the 2 = 4 & 2 to 3 = 8 etc.
Owing to its relatively straightforward implementation in electronic circuitry, the binary system is used internally by all modern computers.
The modern binary number system was first fully documented by Gottfried Leibniz in the 17th century in his article 'Explication de l'Arithmétique Binaire'. Leibniz's uses 0 and 1, like the modern binary numeral system.
In 1854, British ( Irish) mathematician George Boole published a landmark paper detailing a system of logic that would become known as Boolean algebra. His logical system proved instrumental in the development of the binary system, particularly in its implementation in electronic circuitry.
In 1937, Claude Shannon produced his master's thesis at MIT that implemented Boolean algebra and binary arithmetic using electronic relays and switches for the first time in history. Entitled A Symbolic Analysis of Relay and Switching Circuits, Shannon's thesis essentially founded practical digital circuit design."
Suffice it to say that there is a lot more about binary & how computers use it on the WIKPEDIA site at : "http://en.wikipedia.org/wiki/Binary_numeral_system";
In other words computing is a hierachical system which begins with small pulses of ON/OFF voltages ie the 0's & 1's, through binary arithmetic which computers can handle, but man finds difficult to, to the next stage which condenses these extremely long binary numbers to a mathematical form called HEXADECIMAL.
These are letters & numbers which can express anything from a memory address to a piece of data.
Next comes a program that "compiles" statements partly in maths & partly in English which endeavours to carry out those ALGORITHMS we spoke about earlier into logical sequences of instructions we ultimately we see or hear from our computers.
This is of course a very potted account & hasn't mentioned OPERATING SYSTEMS & the hardware side that is software driven, by them.
Operating systems are "basic" programs that need to be set up & running before the computer can in any way communicate with us.
This includes programs such as Windows XP & earlier, LINUX, UNIX etc.
When we have an operating system up & running then & only then can we import new programs into the computer's hard drive to carry out all the many things such as wordprocessing, spread sheets, video clips, games etc which modern computers are able to deal with.
The probs start when these complex programs have to interact with one another. That's when the fun really starts !!
They are almost like insects vying for supremacy, sometimes there are fights to the death & at other times peace reigns supreme !!
End Of Homily
Hope you enjoyed that canter through some of the terminolgy used in computing, but as you've probably guessed we've really only scratched the surface.
Kind Regards To You
Eric
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