• Sequential
• Random
• Serial
• Indexed-sequential

1. Use a humidifier: Using a humidifier can help maintain a consistent level of humidity in the computer lab, which can prevent the negative effects of low humidity.

2. Avoid dry air: Avoid creating a dry environment in the computer lab by opening windows or using fans to increase air circulation.

3. Regular maintenance: Ensure that all computer components are properly maintained and cleaned to prevent damage due to static electricity.

4. Backup data: Regularly backup all important data to avoid data loss in case of hardware failure caused by low humidity.

5. Monitor humidity levels: Use a hygrometer to monitor the humidity levels in the computer lab and take corrective measures if the levels fall below a safe range.

6. Use anti-static materials: Use anti-static mats or wristbands when handling computer components to prevent static electricity buildup.

Many components that go into computer systems are toxic and dangerous to the environment if released or disposed of inappropriately.
Heavy metals are used in batteries and circuits and these can pollute groundwater or kill animals if left exposed on landfill. Large quantities of plastics are used in systems, which take a long time to break down, some of the plastic will eventually break down into toxins as it degrades.

• where the new system is completely different from the old one
• if there has been extensive testing of the system and the system analyst has confidence in its functionality
• If the system is not critical

A primary key is a table field that uniquely identifies each record and ensures that duplicate entries are not allowed

A foreign key is primary key of a parent table placed in a child table to ensure that any record added to a child table is related to the one in parent table.

A foreign key is a field (or a set of fields) in one table that refers to the primary key of another table. It is used to establish and enforce a link between the data in the two tables, ensuring referential integrity.

(a) \(F C_{16}\)

(b) \(8 A_{16}\)

(c) \(93_{10}\)

• user changes his mind
• new government legalisation/company policy company changes
• changes in hardware
• changes in software/upgrades/new versions
• improved operating efficiency/ease of use

• problem recognition involves the system analyst identifying and accepting the existence of a problem in the current system
• problem definition involves the analyst studying the system to understand its operations and shortcomings

• It transfers data signals from one node directly to another in the network without broadcasting

A file is a collection of related data given a unique name while a folder is named storage location on a storage media that contains related files

• Fibre optic cable would be used because it has a higher bandwidth, allowing faster communication in the main part of the network. It is also more secure as it cannot be tapped.
• Firewalls filter the data in and out of a network. Each packet is examined against the filter rules and if a packet is flagged, it is dropped. Only data packets that satisfy the filter rules are allowed through the firewall, thus providing a layer of security for the network.
• A satellite system would be better as it does not rely on wifi, cellular etc. It is not subject to interference and is reliable in remote conditions
• Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder, a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods..

Manages memory (RAM) 

• Allocates memory to programs currently executing •

Ensures programs/data do not corrupt each other: Ensures all programs and data including itself is stored in correct memory locations

Manages processes: Ensures different processes can utilise the CPU and do not interfere with each other or crash •

Allows a user to run programs : On a multi-tasking O/S ensure that all tasks appear to run simultaneously

• Allocates time slices 
• Scheduling of programs
• Handles interrupt
• Allows a user to configure hardware

1. Operating system manages the computer hardware thus without it the programs cannot communicate directly to the hardware
2. Provide a user interface through which a user can give instructions to the computer. Without a user interface, it would be difficult to load or run programs
3. other programs depend on the operating system to load them into the memory , allocate resources and schedule processor time, Without operating , there would be nothing to co-ordinate the execution of multiples programs
4. The OS organizes data in files and directories, making it possible for programs to save, retrieve, and modify data.
5. Without it, programs wouldn’t know where or how to store data.
6. The OS controls access to files, memory, and devices, ensuring that one program doesn’t interfere with another.

input

• from sensors
• from camera images [Max 2]

processing

• analyse data from sensors
• calculate average traffic flow/speed
• send signals to adjust change lights/timing

output

• change lights at the junction
• change timing plan

Acme company needs to ensure that if they are reselling the drives they wipe the drive (this should be done regardless of the destruction of the drive) to the DoD standard.

• Disassemble the drive by pulling it apart the drive so that the data would not be accessed
• Destroy the metal disk either by drilling holes so it cannot be read
•  Encrypt drives with passwords that are not accessible
• Degaussing the hard drives
• Use specialized overwriting software

This would ensure that any software cannot be used to locate files.

• Security
• Installation cost
• bandwidth the medium can support
• Flexibility e.g wireless media
• Distance

• VM is used when RAM is full  i.e part of the secondary storage used as (temporary) RAM/VM
• Data from RAM is moved to the secondary storage/VM (to make space in RAM)
• RAM can then be filled with new data
• When data in VM is needed it is moved back to RAM

• It ensures that each row has a unique and non-null primary key

• Used to resize the image
• Used to rotate the image
• Used to move the image

• Resizing using resize handles
• Rotating
• Cropping
• Flipping
• Moving