Network issues and communication

Security issues and regarding data transfer

Security issues with using a computer network:

["If your computer is connected to a network, other people can connect to your computer."]

There are several security issues that you computer might get to face when using or connecting with a computer network such as:

• Hacking....A person who gains unauthorized access to a computer system are called HACKER. They usually discovered and exploited computer system failure. 
• Viruses....Software that can 'infect' a computer (install itself) and copy itself to other computers, without the users knowledge or permission.
• Malware...is short for malicious software. Malware is the name given to any software that could harm a computer system, interfere with a user's data, or make the computer perform actions without the owner's knowledge or permission. 

Sometimes the internet is not policed; and you might existence to the unappropriated websites. 

Physical security:

• Don't let an unauthorized sit in front of your computer.
• Keep your office door lock.
• Use password

You can prevent these by: using anti-malware software; using firewall; secure your network, etc.

Avoiding password interception:

• Use anti-spyware
• Change the password regularly...[The password should be strong and hard to identify, with lowercase and uppercase alphabets and numbers (number should not be easy to guess e.g. date/month/year of birth or age etc). You also can use the symbols show on the keyboard if they allow].
• Preventing unauthorized access
• Securing your data...Encrypt
• Installed firewall

Authentication Techniques (security):

• Biometric methods: refers to metric related with human characteristics such as fingerprint recognition,  iris recognition, face recognition, voice authentication, retina scan etc.......
• Magnetic stripes: 
• Id cards: 
• Passports:   
• Physical tokens: e.g. security token, hardware token, authentication token, USB token, cryptography token, software token, virtual token, or key fob are used to prove one's identity electronically.

Antivirus software and avoiding viruses:

There are some simple ways to prevent your computer from getting viruses:

• Install antivirus software;-detect and prevent viruses from getting into your computer
• Download and install software from internet can infected your computer with viruses
• Don't open attachment from strangers in the email.
• Install firewall to protect your computer. 

Data Encryption:

Encryption is a process of converting information into a form that is meaningless to anyone except holders of a ‘key’. 

Uses; 

• Secure the important or personal data.
• Encrypt data.
• Prevent the data from the hacker.

Typical data protection act:

Many governments have realized the need to protect peoples' data from misuse, and have created Data Protection Acts. These are a legal rules that must be followed by any business of organisation that keeps a database containing peoples' personal data.

A typical Data Protection Act might include the following rules;

• Data must only be kept if it is necessary for the business / organisation (e.g. a store shouldn't keep details of your political or religious views - they don't need to know this!)
• Data must be accurate and kept up-to-date (it is the duty of the business / organisation to make sure the data has no errors)
• Data must not be kept longer than necessary (e.g. you can't keep a customer's details forever - only whilst they are still your customer)
• Data must be kept secure (e.g. databases should be encrypted, firewalls should be used for networks, etc.)
• Data must not be transferred to any country that does not have a similar data protection laws

KEEP YOUR NETWORK SAFE:)

Networks

Network Devices:

• NIC (Network Interface Card); The small circuit board, which use to add to the motherboard. A computer that is to be connected to the network need to have this. 
• Hub; A device that connects a number of computers to make a LAN. It sent the message that it receive to every computers on the network.
• Switch; A device that connects number of computers to make a LAN, like a hub, but it only sent the message to the address that the message addressed to.
• Bridge; A device that links together two different parts of a LAN.
• Modems; A device that use to converts from analogue to digital or digital to analogue.

Router:

Router; A network device that connects together 2 or more networks.

Router is commonly use to connect your LAN to the internet (WAN) by the cable or wireless LAN connection (WiFi) with wireless router.

WiFi and Bluetooth:

WiFi

WLAN is a LAN that use radio signals (WiFi) to connect the computers to the network instead of cables. There is a wireless switch or router at the centre of the WLAN, which used to receive and sent data to the computer.

Bluetooth

Bluetooth device contain low power transmitters and receivers. When there is another Bluetooth devices that are in range, they will detect each other and can be paired (connected).

Comparing&Contrast 

• Bluetooth has a short-range connections (only a few metres), but WiFi range wireless connections is about 50 m.
• Bluetooth is design to get rid of the cables e.g. USB cables. When using bluetooth to connect to the keyboard or mouse or the printer, there won't be any wires or cable around. However, using WiFi is for connecting to the network, but when using keyboard, mouse and printer there need to have the USB cables to connect.

Internet:

Internet is a inter global connection (connections that are linked together), which connects millions of computers together. This type of network are generally public.

Intranet:

A private network is called 'Intranet', which mean only an intranet users that can access. This type of network provides similar services to the Internet such as email, web page, etc. 

Intranet and Internet

• Intranet is an private network.
• Internet is a public space, a world-wide network. 
• Intranet limited the number of users.
• Number of people using Internet is unlimited.
• Intranet only contain specific group information.
• Internet contain many different source of information and is available for all.
• Internet contains a large number of intranets.
• Intranet can be accessed from internet but protected by a password and accessible only authorized users.

LAN:

LAN stand for Local Area Network, which interconnect in an local/limited area such as school, resident and office building. 

WAN:

WAN stand for Wide Area Network, is a computer network that can be connect in a large area distance.

WLAN:

WlAN stand for Wireless Local Area Network or WiFi, which links two or more devices using wireless distribution method within a limited area such as home, school or office building. 

Using different types of computer to access to internet:

Desktop computer:

Advantages

• Big screen
• Fast processor
• Lots of memory space
• No battery

Disadvantages

• Not portable
• Big and heavy
• Requires a separate monitor
• Needs keyboard and mouse
• Probably without wireless connection

Laptop:

Advantages

• Easy to carry
• Small and light weight
• Portable 
• Powered by battery
• Can connect with wireless network

Disadvantages

• Less memory space than a desktop computer
• Can  go over heat easily
• Easy to be steal or loose

Tablet:

Advantages

• Small and light weight
• Recognizes handwriting
• Long battery life time
• Can connect to internet from anywhere
• Multi-touch screen
• Portable

Disadvantages

• Easy to be damage
• Weak capability
• Small screen
• Can't work with massive amount of data

Phone:

Advantages

• Constant internet access
• Lots of application are in one device
• Portable
• Touchable screen
• Small, can be put in pocket
• Allow easy and quick access to information

Disadvantages

• Small screen
• Weak capability
• Not able to work with massive amount of data

Storage Devices

Magnetic backing storage; 

• Magnetic tapes (type of magnetic backing storage media);  large capacity, serial access medium.

Uses: data back-up, some batch-processing
Advantage: can store large amount of data
Disadvantage: slow (rarely access in an emergency)
-Magnetic tape drive; data storage device that reads and writes data on a magnetic tape.
Uses; offline, archival storage
Advantage: long archival stability, favorable unit cost
Disadvantage: slow sequential access




CD R/DVD R (Recordable); data can be burnt onto them, but not erased. You can keep adding data until the disc is full, but you cannot remove any data or re-use a full disc.
Uses: record audio and another form of data e.g. music, spreadsheet, document video file etc.
Advantage: mass storage capacity
Disadvantages: easily broken, data can't be read properly if there are scratches.

CD RW/DVD RW (ReWritable); data can be burnt onto them and also erased, so that the discs can be re-used.
Uses: record audio and another form of data
Advantage: high data stability
Disadvantages: require special drive to read and write, most of CD players can not play CD-RW


Solid state drives; uses integrated circuit assemblies as memory to store data persistently. It contain no moving parts.
Uses: store data
Advantage: faster, better performance and reliability than HDD, low energy consumption
Disadvantage: expensive

Input and Output Devices

Input Devices:

Sensor; convert a real world properties into data that computer can process e.g.

• temperature sensor-detect temperature (to control the temperature e.g. in science experiments)
• pressure sensor-detect pressure (e.g. someone standing on it)
• light sensor-detect light (control light e.g. in music concert)

Radio Frequency Identification (RFID) readers; used to gather information from an RFID tag, which is used to track individual objects. This performed by the radio waves which use to transfer data from the tag to a reader

 

Uses:

• passports
• smart cards
• airplane luggage
• toll booth passes
• home appliances etc

Magnetic Ink Character reader (MICR);  allows details from bank cheques to be read into a computer quickly and accurately.  

Optical Mark Reader; allows the data from a multiple-choice type form to be read into a computer. 

Uses:

• multiple-choice exam answer sheets 
• lottery forms etc

Optical character reader (OCR); can convert different types of documents, such as scanned paper documents, PDF files or images captured by a digital camera into editable and searchable data.  

Bar code reader; allow the data from bar code (simply numeric code) to be read into a computer.

Uses: Point of sale (POS) etc 

Chip&PIN readers;  use to access the chip on the card.

Magnetic stripe readers; hardware device that reads the information encoded in the magnetic stripe located on the back of a plastic badge. 

Output devices:

Monitor; screen that put up peripheral output to the user e.g. 

• CRT monitor-cathode ray tube-display screen; the type that has been around for years and is large and boxy. 

Uses; design industry

Advantages: colour accuracy andbrightness of CRT monitors is excellent

Disadvantages: heavy and they take up a lot of desk space

• TFT (Thin Film Transistor)/LCD (Liquid Crystal Display) monitor; flat screen monitor, they replaced CRT monitor.

Uses: television sets, monitor screen, mobile phones etc

Advantages: light in weight and they take up very little desk space, also has picture quality that is as good as CRT monitors. 

Disadvantages: the colors are not always correctly transcribed.

• IPS (In Plane Switching)/LCD monitor ; screen technology used for liquid crystal displays (LCDs)

Uses: main limitations of the twisted nematic field effect (TN) matrix LCDs in the late 1980s

Advantages: wide viewing angles, better colour accuracy

Disadvantages: required 15% more power than TN monitor.

• LED (Light Emitting Diode) monitor; semiconductor device that emits visible light when an electric current passes through it.

Advantages: perfectly flat screen, produce very bright image, 

Disadvantages: limited viewing angle, bad pixel and screen uniformity 

Printers:

Dot matrix printer; a type of computer printing which uses a print head that moves back-and-forth, prints by impact, striking an ink-soaked cloth ribbon against the paper.

Uses: multi-part forms and address labels

Advantages:  thicker media better than laser and inkjet printers

Disadvantages: lowest printing costs per page, ink is running out, the printout gradually fades.

Wide formate printer; prints on large paper, which can range from two to more than 15 feet in width.Uses: print banners, posters, trade show graphics, wallpaper, murals etc
Advantages: high quality printing
Disadvantages: taking more time and reducing productivity, increases waste, uses more materials

3D printers;  print out the process that builds layers to create a three-dimensional solid object from a digital model.
Uses : print organs from a patient's own cells, print 3D model
Advantages: can print out 3D shapes, no storage cost
Disadvantages: limitations of size, limitations of raw material

Biometrics
- is refers to technologies that measure and analyze human body characteristic such as DNA and fingerprints  

Producers: Apple, 3M Cogent, Access IS etc

Uses...; Authentication purposes and Identification   

1. Airport security
2. building access - finger print
3. cars- voice recognition
4. blood bank-iris recognition
5. school; recording attendance, checking out library books  and paying for meals 
6. Accessing private room; finger print or eye scanner (iris recognition)

Biomatric can make lot of activities easier like; making the teachers signing in the morning easier, when they arrived at school they just put their thumbs to the scanner....and also paying for meals.

This emerging technology might affected some technologies like the number pad lock at the door because they will use the finger print or eye scanner instead.
Biometrics is a good technology. However, they may affect people's everyday lives; it can erase your finger print if you use the machine(sliding) for a long time. Also it can make people lazy because people will use to the easy machine like this, so when it come the situation like people need to write down the registration instead of using finger print, it would be hard for them. 

3D and holographic imaging 

-Holography is a photographic technique that records the light scattered from an object, and then presents it in a way that appears three-dimensional.

Producers: Ford Motor company, Holographic Marketing System P.Ltd, HOLO 3D Srl, (IHMA) etc
Uses.....

1. Bio medical imaging - digital holograms...DNA, human body, cells, full sized organs, etc
2. Car industry and consumers  - 3D car from transparent
3. Movies - Star Wars and Iron Man
4. Rainbow holograms - security purposes...credit card, car licenses etc

Holograms imaging can make the medical system easier because the digital holograms will help to picture the DNA, cells, inside human body and other things else, so the doctors can see the pictures easier and so the patient.

This technology may affect many other technologies such as; projector that used to put pictures up the big screen.

Holographic imaging is a good technology, but they might affect people's everyday lives, many company that sell projectors might need to close down because the hologram coming up instead of them. However, the holograms help the community secure support and funding for development for increasing regional manufacturing in Illinois.

User interface: is a system that allow the user to interact (command) with the computer.
There are 2 types of the user interface:

• Graphical user interface (GUI)
• Command line interface (CLI)

Graphical user interface (GUI)

GUI is quite easy to use due to the visual nature interface, but this type of user interface use up a lot of power, so the computer must be quite powerful.

• Windows - regions of the screen use to display information (operating system e.g window XP)
• Icons - small pictures used to represent folders and software...
• Menus - lists of options that user can select from
• Pointer - arrow that used to select icons or menus or other things and it also can move around the screen

GUI is sometime called WIMP

-Windows

-Icons

-Menus

-Pointer

Command line interface (CLI)

• User will see the black screen 
• Need to type in the commands to make anything happen e.g. To copy a text file called NOTES from a floppy disc to the hard drive the user would have to type:
  > COPY A:\NOTES.TXT C:\
• Need to learn the whole set of commands 
• There is no visual clue to tell you what to do next!?
• It is quite difficult to use