A.B = A and B
de morgan's theorem
Sunday, 13 November 2011
Thursday, 10 November 2011
logic gates
AND gate: only outputs 1 if both inputs are 1.
NOT gate: changes 1 to 0 and 0 to 1.
OR gate : outputs 1 if has 1 as any input.
NAND gate: only outputs 0 if both inputs are 1.
NOR gate : only outputs 1 if both inputs are 0.
XOR gate : only outputs 1 if the inputs are 1 and 0 pair.
XNOR gate : only outputs 1 if the inputs are the same.
NOT gate: changes 1 to 0 and 0 to 1.
OR gate : outputs 1 if has 1 as any input.
NAND gate: only outputs 0 if both inputs are 1.
NOR gate : only outputs 1 if both inputs are 0.
XOR gate : only outputs 1 if the inputs are 1 and 0 pair.
XNOR gate : only outputs 1 if the inputs are the same.
Thursday, 6 October 2011
key words about the internet.
Internet : It is a world wide “network of networks” which directs information in the subsidized form called packets. There are many different routes that these packets may possibly take from computer to computer. Has all protocols.
Web: A small part of the internet that portrays graphics, text and multi media. It uses HTTP and HTML.
Intranet: A closed off network that can not be accessed by the public. Uses the same technologies as the internet. Often used by businesses and organisations.
Extranet: A small piece of the intranet that is accessible via the internet. This available to the public.
Packet: A piece of a larger piece of information. It contains a header, the IP address of the clients and of the target server and its sequence number, a payload – the information wishing to be transmitted and a trailer, this is used for error checking.
Router: Sends packets in the general direction of its destination. This is a specialised piece of computer.
Domain Name: An easy to remember sequence of characters. This can be translated into an IP address. It is generally the top level and first level domain.
IP Address: A unique twelve digit number that is divided up into three digit with a point in between. Each three digit can be defined by a byte of information. On 32 bit operating systems the maximum IP can be 255.255.255.255.
Domain Name Server (DNS): Translates domain names into IP addresses. Constantly updates for new domain names.
Internet Registries and Registrars: Registries manage sections of IP addresses defined by countries. Registrars allow access to the distribution of these IP addresses.
ISP: Internet Service Provider. Provides internet connection.
URI: Uniform Resource Identifier. Gives a unique identifier, can either be a URN (name) or URL (location).
URN: Uniform Resource Name. Unique name of something, (can’t find its location from this).
URL: Uniform Resource Location. Unique location of something, (no name).
Client: A computer that is trying to access a network and receive information from it, eg a web page.
Server: A computer on the network that gives the client the information it requires, eg the web page.
TCP/IP: Both protocols. TCP breaks it down into packets and sends it off. IP finds where it needs to go next. They work in conjunction.
Wednesday, 21 September 2011
What is HTML? What is CSS
HTML stands for HyperText Markup Language, it is the markup language for programing webpages it is divided up by tags. All tags fall in the Head or Body main tag. All tags have <> around them e.g. <title>. to stop using that or Closing as it's called is when you repeat the tag a part from after you put < you put a / as well, but if you wish to close the tag in the tag put the / before the >. e.g. </title> or <br/>.
Useful tags:
<head>
<body>
<h1>
<title>
<p>
<br/>
<strong>
<ol>
<ul>
<li>
<tr>
<a href="">
<img src="">
<i>
CSS stands for Cascading Style Sheets, it allows for more flexibility in the coding of webpages in tags you can add a "style=" in the tag followed by an variable e.g. <p style="colour:blue">hello </p>. To a another variable just add a ; after the previous one. e.g. <p style="colour:blue;font-size:small">hello </p> . you can define a set of variables, to run for all tags of that type. This is done by nameing the type then put in the varibles as previously in {} right after <style type="text/css"> all of this should be put in the <head> tag. e.g. <style type="text/css">p{color:blue;font-size:small}</style>. You can also add your own "class", which is a custom interchangeable variable, by haveing the same tag as before but instead of useing a already exsiting tag put anyword you wish to use but put a full stop in front of that word. e.g. <style type="text/css">.anyword{color:blue;font-size:small}</style>. when you wish to use it put in the desired tag put class="word". e.g. <p class="anyword"> hello </p>
Useful tags:
<head>
<body>
<h1>
<title>
<p>
<br/>
<strong>
<ol>
<ul>
<li>
<tr>
<a href="">
<img src="">
<i>
CSS stands for Cascading Style Sheets, it allows for more flexibility in the coding of webpages in tags you can add a "style=" in the tag followed by an variable e.g. <p style="colour:blue">hello </p>. To a another variable just add a ; after the previous one. e.g. <p style="colour:blue;font-size:small">hello </p> . you can define a set of variables, to run for all tags of that type. This is done by nameing the type then put in the varibles as previously in {} right after <style type="text/css"> all of this should be put in the <head> tag. e.g. <style type="text/css">p{color:blue;font-size:small}</style>. You can also add your own "class", which is a custom interchangeable variable, by haveing the same tag as before but instead of useing a already exsiting tag put anyword you wish to use but put a full stop in front of that word. e.g. <style type="text/css">.anyword{color:blue;font-size:small}</style>. when you wish to use it put in the desired tag put class="word". e.g. <p class="anyword"> hello </p>
Tuesday, 6 September 2011
Computing is a fascinating field of study which has produced some incredible innovations.
A recent innovation is 3D technology, this has caused 3D in cinemas, television and gaming, to take off like is has never done before.
Filming in 3D is very easy as all you need is two cameras and then all you need to do is have them apart from each other by about 65mm (closer or further, depending on the shot) which is the average distance between the eyes. Displaying 3D is where it gets trickier as you have three different ways you can display it within the cinema environment. The first way and the cheapest is anaglyph. Anaglyph is displaying an image as having both the left image and right image as one image but the left image is displayed in red and the right image is displayed in blue which is then filtered out by the left lens in the 3D glasses by being blue and the right one being red. This for obvious reasons is not the most realistic 3D image. The next choice is the one currently used in cinema which are in their original colour unlike anaglyph. It works in a similar way but requires two projectors and each projector displays a different polarized image where the lenses in the glasses are also polarized allowing you to see the left image with the left eye and the right image with the right eye. The third and most expensive way is using active 3D glasses which compared to the ones before are passive 3D glasses. This uses LCD lenses which can black out the lenses alternatively in conjunction with the projector which would display the left and right images alternatively at about 50 frames per second. This is credited as being the best form of 3D but due to the fact that the glasses require batteries to run and are expensive to produce this is not the most financially viable for cinemas to display 3D.
3D in gaming has gone with option 3 as the only option as the higher quality image is worth it. But recently Nintendo has released the first hand held console in 3D in addition it’s the first hand held console that features glasses-free 3D screen. The way this works is shown in the graphic below:
The revolution in 3D has been led by and is still pretty exclusive to the cinema. They had started to get a fewer people visiting the cinema, because of things such as illegal viewing of films on the internet and people had quite a lot of films at home and the cheap price for rental films and the fact consumers were then willing to wait for it to come out on DVD or BLUERAY. This meant the cinemas had to once again restructure the “experience you can only experience at the cinema” and to make the visit to the cinema a notable event which they pushed with 3D as it costs too much for everyone to have it in their homes at the moment.
I think that 3D still has a long way to till it reaches its prime but it’s the only way to go as we live our lives in the realm of 3D.
What is the difference between Computing and ICT?
ICT is learning how to uses of programs and putting that knowledge in to practice a business context and involves a lot of analysing and evaluating. Computing covers the way computers and programs work. Computing involves a lot programming. The skills i would expect from an ICT expert that if you could not work out how to use a programme they would help you. The skills i would expect from an computing expert is that if there was an hardware problem (blue screen of death) or software error e.g. bad installation or bug which will need to be solved (reprogrammed). In simple terms ICT is using a computer and programmes where as computing is working out how to make computers and programmes work.
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