Computers in the real worldObjectives

• Look at what roles computers lead in our lives.• Understand the uses of computers in different

areas of society• Look at how our lives have changed as a result

of computers

Computers in the real worldThe main areas of computing

• Entertainment• Business• Financial / banking• Education• Government • Commerce / shopping

Computers in the real worldEntertainment

• Technology has changed the way we are “entertained”

• This includes– TV / video– Gaming– Communication / socializing – Reading!!!– Music

Computers in the real worldQuick quiz ... Cookie for winner!

• 1 . What does HDMI stand for?– A. Heavy duty multimedia interface– B. Hairy Dave must be interesting– C. High definition multimedia interface

• 2. What does HDMI do?– A. Allows TV’s to connect to the internet– B. Connects high definition devices to a TV– C. Allows PS3 to be connected to a TV

Computers in the real worldQuick quiz ... Cookie for winner!

• 3 . What is the difference between 1080p and 1080i?– A. 1080p displays all lines in order while 1080i displays

only odd lines– B. 1080p displays all lines in order while 1080i displays

only even lines– C. 1080p displays all lines in order while 1080i displays

odd lines and then even lines.• 4. When will analogue TV be switched off?– A. 2010– B. 2012– C 2016

Computers in the real worldAnswers

• 1 . What does HDMI stand for?– C. High definition multimedia interface

• A HDMI cable is capable of transmitting a 1080p video and audio.

• It can not send surround sound!• The resolution of 1080p is 1920 x 1080• 1080p is known as “full HD”.• Not all devices support full HD– The Nintendo Wii is 480p

Computers in the real worldAnswers

• 2 . What does HDMI do?– B. Connects high definition devices to a TV

• You can also connect HD by– SVGA (same as used by your computer)– Component (uses lots of connections!)

• HDMI carries both video and audio– But you would normally connect audio separately

to use surround sound!

Computers in the real worldAnswers

• 3 . What is the difference between 1080p and 1080i?– C. 1080p displays all lines in order while 1080i displays

odd lines and then even lines• P stands for progressive while I stands for interlace• Interlace will do odd lines first and then even

lines. This results in motion which is less smooth.• Progressive does each line in order. This results in

a much smoother image but obviously costs more.• Full HD is 1080p while HD can mean 480, 720 or

1080i!

Computers in the real worldAnswers

• 4 . When will analogue TV be switched off?– B. 2012

• Analogue TV in the UK only has 5 channels • By using digital we can fit more channels into

the same transmission• HD signals will soon be transmitted, these will

NOT be 1080p! Most likely 480p or at a push 720p

• A lot of areas in the UK have already been switched off

Computers in the real worldEntertainment

• How has ICT changed the way we enjoy ourselves?– TV – Social networking– Gaming– Music and films

Computers in the real worldPause live TV

• A lot of devices can “pause” live tv• Inside the device is a– TV receiver– A micro-processor– A hard drive– Outputs to connect to the TV

Computers in the real worldHow does it work?

1. Pause is pressed and a signal is beamed to the device

2. TV signal is then saved onto a hard drive

3. When play is pressed another signal is sent to the device

4. Video will play back from the hard drive until it has caught up

to the live signal!

Computers in the real worldSocial networking

• View facebook in plain english

Computers in the real worldSocial networking

• Twitter is a micro-blog• A micro-blog allows people to post what they

are doing or thinking onto the internet.• Twitter is now a great tool for monitoring fast

moving situations quickly.

Computers in the real worldTwitter case study

• Twitter uses a tagging system to allow people to “tweet” about the same topic.

• #getmehome was used when thousands of people were stranded.

• People would tweet that were stranded, that a airport was closed or even that seats were available on a train!

• People used this to find to arrange alternative arrangements

• Link to story

Computers in the real worldCommunicating on the internet

• Communication using technology is rapidly changing. We have– Instant messaging– Micro-blogging– Texting– Forums + comments– Email– Voice over IP (like skype)– Collaboration software (like google wave!)

Computers in the real worldActivity

• Choose either– Google wave OR– Voice over IP (VoIP)

• Decide in small groups how you would use the technology for yourselves.

• Prepare a 1 min (MAX!!!) presentation to persuade the rest of the group to use the technology– For example you may use google wave to organise the

ultimate 16th birthday party– Or use VoIP to reduce calls to your mates to get your

parents off your back!

Computers in the real worldTUNES!

• The way we listen to music has changed!• Consider the following services– Last.fm (or music on demand)– Squeeze box (music around the home)– Itunes (MP3 music download)– Jamglue (edit and mix music online)

• This is not a definitive list!

Computers in the real worldTUNES!

• The way we listen to music has changed!• Consider the following services– Last.fm (or music on demand)– Squeeze box (music around the home)– Itunes (MP3 music download)– Jamglue (edit and mix music online)

• This is not a definitive list!

Computers in the real worldKey technologies

• Streaming• Peer-to-peer technology• MP3 music compression

Computers in the real worldYour activity will be...

• You will be adding these technologies to your revision power point!

• Make sure you understand them!

Computers in the real worldStreaming

• Streaming is a special way of listening to music or watching video.

• You tube uses steaming to send you video.• This means you do not have a copy of the

video but you get to watch it.

Computers in the real worldHow streaming works

1. A request is sent to you tube’s server

2. Video data is sent back to the user

Computers in the real worldHow streaming works

3. Your web browser will buffer the video. The symbol on the shows buffering is occurring

4. Data is continuously sent until the video has completed or the

user stops watching.

Computers in the real worldStreaming

• Streaming allows you to watch/listen to media as it is being downloaded.

• It is buffered which means that you download a bit first before watching.

• Buffering aims to stop “stutters”– A stutter occurs because your browser has run out

of video to play!– The faster your internet connection the higher the

quality of video you can stream– We will look at this in detail later in the course!

Computers in the real worldP2P

• Peer to peer (or P2P) has a really bad rep!• Essentially it is a tool to allow you to

download large files quickly without relying on a single server to host it.

• The idea is that the more people who have the file the faster it will be for others to download.

• This is known as seeding (hosting a file) and leaching (downloading a file)

Computers in the real worldP2P – how does it work

1. A file is split into lots of different parts.

Computers in the real worldP2P – how does it work

2. Computers accessing the file will download different parts of

the file

Computers in the real worldP2P – how does it work

3. Computers will then download the rest of the file

from each other

Computers in the real worldAdvantages of P2P

• As computers download from each other this means that everyone will get the file faster

• It can cope with interruptions to the download (e.g. Crashes or switching PC off)

• It puts less strain on the host (seed) which saves them money

• All the computers working together is known as a swarm!– It is an example of distributed computing!

Computers in the real worldDisadvantages of P2P

• People do not like having their internet connection used by others to download a file.

• It is used to share illegal content• If there is no seed then people may not be

able to download the whole file.• A lot of viruses can be found in P2P networks.

Especially in illegal content.

Computers in the real worldMP3

• Music files tend to be MP3• This stands for MPEG layer 3 or• Moving Picture Experts Group Layer 3• Yes it is based on videos!!! Odd isn't it!• A MP3 can reduce the size of a CD – Normally 10% of the original size!

Computers in the real worldCompression

• When a file has it’s files size reduced we call this compression.

30 Megabytes 30Megabytes

Computers in the real world30 second explanation of MP3 compression

• MP3 uses lossy compression. • This means that parts of the file are thrown

away! – I.e. It looses quality which is why it is called lossy

• If you convert a MP3 back (decompression) it will not be the same file!

• The bit rate of an MP3 means less information is thrown away. – The higher the bit rate the better the quality

Computers in the real worldActivity

• Choose either– Streaming– MP3– P2P

• Create a podcast explaining how the technology works

• Ensure that your podcast explains the idea as simply as possible

• Research the technologies to ensure you fully understand it.

Computers in the real worldweb technologies

• The most use software on the web is...

• A DATABASE!!!

Computers in the real worldContent management

<php>.....</php>

1. Page content is loaded from the database and combined using a

template written in a programming language

2. The result is converted to HTML (web page) and sent to the user. This means that a content can be

built on demand!

Computers in the real worldcontent management

Watch video on content management

Computers in the real worldCase study

Title

Body / main text

Main image

Related links

Computers in the real worldBBC case study

• Journalists will use a web-form to upload their story.

• They will set their own – Title– Story– Image – Related links

• This then is uploaded and will be part of the main website.

• This means that all pages look the same and do not require any programming knowledge.

Computers in the real worldOnline shopping

• Online shops use content management.• Additionally you will have an account with

them to store your details.– This will be stored in the database!

• A purchase is also stored in a database. This allows them to easily track orders and manage stock.

Computers in the real worldActivity

• Content management is used in blogs!• Create a blog (https://www.blogger.com/)• Write a case study explaining how you can

make a blog entry using the content management software of blogger.