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4Feb/100

Computer Science: Study Notes [Outsourcing] – yr 12

Advantages
Give business freedom to focus on core compentencies Cost an efficiency savings
Access to cheaper labour Allows the company to focus on core operations'
Access world class help desk support The company doesn't have space to accomidate a new employee and building onto an existing building is costly or cannot be done because of lack of space.
Access state of the art technology Staff flexibility, allows the company to access additional resources
Disadvantages
Wages of Australian workers may be pushed down. Loss of control over the outsourced task
Quality of services recieved from outside sources may not be of the same standard Hidden cost  - one may sign a contract that contains hidden costs
Local workers have to compete on the global market Threat to security and confidentiality - outsourcing propietry or knowledge, drawings, formulas. - may be at risk as these would have to be sent to the outsoucing company
Security issues in relation to sensitive data
language and cultural barriers
Alternatives to outsourcing
Provide pathways for students to develop in these ICT areas
Provide incentives to business to take on trainees
Provice accredited training organisations to deliver ICT cources to a set standard
Scholarships
Tax benefits to Australian businesses to emply australian ICT workers over outsourced workers
4Feb/100

Computer Science: Study Notes [Types of Computers] – yr 12

Handhelp Computers Single User computers that provice ease of portability because of their small size.
Such as PDA's, mobiles phones so forth
Portable Computers Can be caried around easily eg laptops, notebooks, sub-notebooks or tablet computers
Thin client computers Low-cost centrally managed computer with no extra drives, such as CD/DVD or expansions slots. They have limited capabilities and perform only essential applications. Thin clients download software from a network when needed making support, distribution and updating of software easier and less expensive - one example of this is cloud computing.
Desktop Computers Relatively small, inexpensive single-user computer systmes that are highly versatile. Desktop computers can provide sufficient memory and stoage for most business computing desks.
Workstations Workstations are more powerfull than PC's but still small enough to fit on a desk. They are used to support engineering and technical users who perform heavy mathematical computing, computer aided design (CAD). Users need powerful CPUs large amounts of main memory and high resolution graphics displays.
Servers Servers are computers used by many users to perform a specific task, such as running nework or internet applications. Servers usually have large memory and stoage capacities along with fast and efficient communications abilities. Servers offer scalability easy to increase the processing capability so it can handle more users data in a given period.
Scaling up adds more powerful processors
Scaling out adds many more equal or even less powerful processors to increase the total data procession capacity.
Web Server Handles traffic and communications -- needs to be refined..
Internet Caching Server Stores websites that are used frequently by an organisation
Enterprise server Stores and provides access to programs that meet the needs of an entire organisation.
File server Stores and coordinates program and datafiles
Transaction Server processes business transactions
Blade server houses many computer motherboards that include one or more processors, computer memory and computer storage and computer network connections. They all share a common power supply and air cooling source with a a single chassis. This makes the blade server more powerful and less expensive than a traditional system.
Server Farm When an organisation houses a lage number of servers in the same room where the access to the machines can be controleld easil managed and maintained the facility is called a server farm.
Mainfraae Computers A large powerful computer shared by doezens or hundres of concurrent users connected to the machine over a network. The mainframe computer much reside in a data center with special heating, ventilation and air conditioning equipment to control the remperature, humidity and dust levers. Most mainframes are kept in a secure data center with limited access to room.
Mainframes can handle the millions of daily transactions associated with airline hotel/motel reservation systems.
Supercomputers The most powerful computers with the fastest processing speed and highest preformance.
Microcomputer Small personal computers PC's that are based on an intergrated circuit or chip called a microprocessor and are designed for use in homes and small organisations.
4Feb/100

Computer Science: Study Notes [Programming Def's] – yr 12

Reference http://4dahl.com/howto/programdevelopmentsteps.html
Word Definition
Algorithm A set of simple instructions that combine to accomplish a task.
Data Validation
Global data Data that can be addressed by any process while in kernel mode for example tables such as open file table
and process tavle and other data maintained by the kernel such as buffer
Local data
Algorithm A detailed outline
A recipe
Pseudo code Pseudo English is an intended outline with key words showing structure.
Modular design Modular design involves grouping tasks together because they perform the same function.
Top-down development IN the top-down development of a program design, a general solution to the problem is outlined first. This outline is then divided gradually in to more detailed steps until finally the most detailed levels have been completed. It
Types of programming
Procedure Driven Programming The procedure-driven design bases on the idea that the most important feature of a program is 'what' it does.
Event Driven Programming The event driven program design is based on the idea that an event or interaction with the outside world can
cause a program to change from one know state to another.
Data driven Programming The data driven program design is based on the idea that the data in a program is more stable that the processes
involved.
Object oriented programming object oriented programming breaks the problem into a set of separted objects that perform actions and relate to each other.
4Feb/100

Computer Science: Study Notes [OSI Model + Summerised ] – yr 12

The OSI Model
Definiton Protocols
7. Application layer This layer interacts with the software -> closest to the end user ftp, http
6. Presentation responisble for delivery and formatting of information ASCII, LPP
Host
Layers
5. Session Controls the connections between computers. Establishes, manages
and terminates the connection between local and remote applications
ADSP, ZIP, PAD
4. Transport Provides transfer between users, reliable services to the upper layers
controls the flow, segmentation/ desegmentation and error control.
TCP, UDP, SPX
3. Network Provides the functional means of transferring data from source to
the destination as well as amintain qaulity of service requested by the transport layer.
IPv4, IPv6
Media
Layers
2. Data-link Provides the function and procedural means to transfer between
network devices as well as finding possilbe errors in the physical layer.
Ethernet, ATM
1. Physical The physical devices that make up the network - such as hubs, switchs
and calbes
OSI MODEL All People Seem To Need Data Processing
Summerised OSI Model Protacals
7. Aplication Layer User Application Services DNS, FTP, HTTP, SMTP
6. Presentaion Layer Data Translation; Compression and Encryption SSL
Host
Layers
5. Session Layer Session Establishment, Management and Termination NetBIOS
4. Transport Layer Flow control, Connections TCP, UDP
3. Network Layer Logical addressign; Routing; error handling and diagnostic IP, NAT, IPv6
Media
Layers
2. Data-Link Error detection and handling of the physical layer; Addressign; Data Framing Logical Link Control ATM, PPP
1. Physical The network topology and design, hardware specifications. Ethernet
4Feb/100

Computer Science: Study Notes [Some Hardware Def's] – yr 12

Here are some more study notes, not sure where I got the definitions from (might have changed it around a bit as well) - if you find the site I might have got this from please send me the link so that I can reference it.

Hardware
CPU Central processing unit
ALU Arithmetic logic unit - a digital circuit that performs arithmetic and logical operations
Bus a bus is a subsysem that transfers data between components inside a computer or between computer.
Multi core processor architectures Multical core processors combine two or more independent cores into on package. Thus allowing the cores to process different instructions in a singal cycle.
GPU Graphics processing unit
Switch Allows compatiable devices connect and share data amongst each other
Router A most sophisticated network device then either a switch or a hub, as router maintains a list of tables of devices and paths to those devices, thus allowing
optimum network efficentcy as the router is able to directly transmit signals to the device, whether the device is on a LAN or WAN. The router also acts as a barrier between the internet and LAN's or MAN's and so forth - thus the router eliminates communcation from the internet  to these devices. The router maintians a list of current connections and from the internal LAN to the External WAN (i.e. the Internet) thus multiple devices from within the network are able to share the same ip address as well as commmunicate simaltaniously.
Wireless modem A device that converts digital signals from a PC to analog for transmission on public telephone networks.
Wireless access point A device which allows wireless communication devices to connect to wired networks.
Router VS Switch A router is a more sophisticated network device then either a switch or a hub. Router pupose, to join multiple network subnets - switch connects different network segments