[ArinN_]

a) List the steps in a GA. Suggest use pseudo code to show the steps, the iterative nature and exit criteria

Define algorithm {
* Choose an initial population of individuals: P(0)
* Evaluate the fitness of all individuals of P(0)
* Choose a maximum number of generations: t_max
* Loop while not satisfied and t < t_max:
– t = t + 1;
– Select parents for offspring production
– Apply reproduction and mutation operators
– Create a new population of survivors: P(t)
– Evaluate P(t) <– #Must meet with exit criteria#
* end loop
* Return the best individual of P(t)
}

[ArinN_]

a) Describe the 4 listed approaches to Selection.
– roulette wheel selection
– stochastic universal sampling
– tournament selection
– truncation selection

b) Discuss the characteristics of a good selection approach
– Doesn’t lead to premature convergence and doesn’t lead to local minima convergence
– Meets with the situation (For example, Truncation selection isn’t popular unless the population size is large)
– Assures genetic diversity

[ArinN_]

1 ) Describe with an example how run Run Length Encoding can be used to compress an image
– This is the basic idea behind run-length encoding (RLE), which is used to save space when storing digital images.
– In run-length encoding, we replace each row with numbers that say how many consecutive pixels are the same colour, always starting with the number of white pixels.

[ArinN_]

1) What Is File Compression? Why Is It Necessary To Compress Files?
– Compression refers to reducing the original file size.
– Compressed files reduce the time takes to attach, upload and download files. It also helps reduce disk space usage.

2) describe the differences between lossless and lossy compression and give examples
– Lossy compression reduces file size by permanently eliminating certain information. Specifically, it eliminates redundant information, even though the user may not notice it. For example, JPEG is a format that uses lossy compression.
– However, lossless compression retains raster values during compression. At the same time, it still ma ages to reduce file size. For example, LZ77 is a lossless compression file type.

3) Give examples of lossy and lossless image and video file formats
– Lossy: JPEG, MP3
– Lossless: FLAC, ALAC, PNG

[ArinN_]

Temp = […]
int highest = T[0]
int lowest = T[0]

for T[1] to n-1
if T[i] > highest:
max = T[i]
else if T[i] < lowest:
min = T[i]

end loop

print (highest – lowest)

—
Part b:

loop i from 0 to n-1
if inventory[i] < 10:
prices[i] = prices[i]*1.2 (Increase price by 20%)

end loop

[ArinN_]

1. Human interaction with the computer system includes a range of usability problems.

(a) Define the term usability. [1]
– Usability is how well a system could be used.

(b) Identify two methods that could be used to improve the accessibility of a computer
system. [2]
– Text-to-Speech could help people with visibility issues.
– Voice Recognition and Touch screens could help users to navigate and use the system.

4. A small hotel buys a software package to manage their bookings.

(a) Describe two types of documentation that should be provided with the software package. [4]
– Statements that identify attributes and characteristics and the documentation of code and interface of the software.
(b) State two methods of delivering user training. [2]
– Online training & Classrooms (i.e Lecturing)

7. A hardware shop supplies a wide variety of bathroom equipment. There are 15 shop
assistants who serve customers, 3 office staff who handle the administration, and a manager.

A specialized company is asked to design and implement a new computer system for
the shop.

(a)
(i) Identify two different types of users of the system. [2]
– Admin and General user
(ii) Explain the role of users in the process of developing the new computer system. [3]
– Admin users are like the shop owners who has full access/control over the system while a general user might be the shop’s employees using a cashier or an accountant loging datas.

(b) Describe why it is useful to produce more than one prototype of the new system. [2]
– By producing multiple prototypes, the owner of the shop could choose their favourite one thus improves customer’s satisfaction but moreover, by producing multiple prototypes the company could develop ones that are considered good and possibly sell it.

(c) Outline two problems that may occur when transferring data from the old system to the new system. [4]
– 1. New interfaces could be troublesome and takes time to get used to.
– 2. Datalost could occur if there’s a need to transfer data from the old system.

The new system is implemented using parallel running.

(d)
(i) Outline what is meant by parallel running. [2]
– Parallel running is when both the new and old system runs at the same time so the change to the new system would occur over a period of time.

(ii) Outline one reason for choosing parallel running as opposed to a direct changeover. [2]
– By running a parallel system, there would be more time for users to get used to the new interfaces so there would be no loss of momentum in the work amount as the old system is still in place and the change wouldn’t suddenly interrupt the work flow.

2021 Paper

12 A school has a cabled network and wishes to add wireless networking access for the whole campus.

Describe 2 hardware components the school will need to implement the network
– Router & Network Switch (Preferably a firewall switch)
Identify 2 advantages to the students of the new wireless network
– 1. Easy access to the internet and knowledge while on the go.
– 2. No need to stick to using computers in the computer lab.
There are concerns that unauthorized people may gain access to the data on the network

(c) Outline 2 methods that the school could employ to prevent network data being accessed over the wireless network. ( see https://mecsunlimited.com/top-5-ways-to-secure-your-schools-wireless-network-in-a-byod-era/
– Use a firewall with role based access with encryption
– Create security practices and protocols

Review Computer Architecture
2.1.1 Outline the architecture of the central processing unit
– Control Unit, ALU (Arithmetric Logic Unit) & Cache
2.1.2 Describe primary memory.
– Primary memory is the main memory where data are stored while the computer is turned on (such as cache and ram)
2.1.3 Explain the use of RAM, ROM and Cache memory.
– Cache memory is attached to the central processing unit (CPU) and is the fastest memory unit. Cache predicts sets of data the CPU would used next from the past repetition of data requested from RAM.
– A RAM or Random Access Memory is where programs processes resides in while it is running.
– A ROM or Read-only Memory is usually hard-mounted onto the mainboard and is where the BIOS is stored. (ROM would be the first thing a computer access when turning on)
2.1.4 Explain the machine instruction cycle ( Fetch Decode Execute )
– Fetch: Firstly, the instruction is fetched from the PC and copied into the memory address register then the address is sent down the address bus to the main memory then the instruction is sent back down the data bus to the memory buffer register and from the memory buffer register, the instruction is copied to the current instruction register
– Decode: The contents of the current instruction register are sent to the control unit which makes all the necessary changes to logic gates and communication channels.
– Execute: The tweaked instruction then get executed by the ALU (Arithmetric Logic Unit)
– Store: The result generated by the operation is then stored in the main memory, sent to an output device, or saved in the accumulators. Based on the condition of any feedback from the ALU, Program Counter may be updated to a different address from which the next instruction will be fetched.

[ArinN_]

1) Discuss the differences between usability and accessibility.
– Usability is a measure of how well a user can use a product/design to achieve a goal effectively and efficiently while accessibility is how accessible a product or application is to a user.

2) List 6 examples of assistive technology.
– Magnifiers
– Text-to-Speech softwares
– Phones
– Personal hearing amplification system
– Reminder apps
– Audiobooks

3) Select an operating system, example Windows 10 and describe the accessibility features for vision and hearing. Link for Windows 10, but you may choose a different operating system https://www.microsoft.com/en-us/accessibility/
– Windows 10 support speech search, magnifier, brighter screen, narrator, dictation, and Windows Hello sign-in for those who live with dyslexia, seizures, autism, or other cognitive differences.

4) What is neurodiversity?
– Neurodivergent refers the an individual who has a less typical cognitive variation such as Autism, ADHD, dyslexia, dyspraxia etc.

5) Briefly describe some ways that the operating system selected in number 3 caters to neurodiversity.
– Windows 10 help constructing sentences with text suggestions, supports Fluent Sitka Small and Fluent Calibri fonts and other features which reduce visual crowding and make reading easier for people with dyslexia.

6)Choose a device and identify a range of usability problems that can occur in that system. Device can be PCs, digital cameras,
cell phones, games consoles, MP3 players or other commonly used digital device
– Cell phones:
– Mobile phones usually have small screens thus it is hard to see for some individuals.
– Blind people can’t look at screens.
– Calling on phones are useless for people with hearing disability.

7) Select a system from ticketing, online payroll, scheduling, voice recognition. For selected system identify a range of usability problems
that can occur in your system.
– Ticketing
– Usability Problem: Maybe inefficient and slow.

8)For the moral, ethical, social, economic and environmental implications of the interaction between humans and machines. For each one briefly discuss the pros and cons

Moral/ethical implications of the interaction between humans and machines:
– Robots and AI could be used in warfare, for example, drone attacks in Afghanistan, etc.
– Robots and AI could be used for criminal purposes
Social implications of the interaction between humans and machines:
– Less human-to-human interaction; not getting to meet people in the shop for example; rather, interact with robots instead
– More leisure time, since the robot is cleaning up the kitchen etc.
Economic implications of the interaction between humans and machines:
– A new area of manufacturing and business, and employees that go with that.
– Un-skilled and repetitive-task workers lose their jobs to robots
Environmental implications of the interaction between humans and machines:
– Carbon emissions through excessive travel could be lowered since much more can be done/made in the home by robots and 3d printers.

[ArinN_]

System backup
What is data redundancy and how can it be used to prevent data loss.
– Data redundancy is when there are two identical sets of data stored in a server or in the same network. This could help prevent data loss as the second set of data would act as a backup for the primary data.

Activity A list a range of causes that can result in data loss. Choose 4 and explain by giving an example. Example user error.. User hits exit without saving and suggest how that might have been prevented
– Software corruption for example, poorly managed data system of Software. Suggestion: Inform the developers.
– System/Hardware Malfunction for example, Old hard disk failed to correctly read or write the data on the disk or the reader-head is broken. Suggestion: Use raid on hard drives and make sure to keep regular backups.
– Computer Viruses for example, the most recent largest ransomware attacks (WannaCry) or zero-day exploits. Suggestion: Always keep servers and computers updated and if necessary, use anti-viruses.
– Natural Disaster for example, Flood, Fire, Earthquakes, etc. Suggestion: Store backups off-sites in multiple locations if possible.

Activity B Using an example other than school records outline the consequences of data loss.
– One example is, Adobe’s Lightroom update. They lost all the assets and data for iphone users thus a lot of people stopped using their services and there are people starting to post alternative applications that are cheaper and does the same thing as Adobes’.

Activity C You have been tasked with Implementing a set of procedures to limit the risk of data loss. Details these with an explanation of why they are necessary ( use the same scenario) as in Activity B
1. Backup.
2. Make sure that the updates are correct.
3. Have a way to reverse back.

Components of a computer system
Past Paper Question

A small company has a LAN connecting its various desk-top computers and peripheral devices.

The company is going to provide Internet access to its LAN.

(a) State the name of an additional hardware device that would be required to permit
Internet access. [1 mark]
Lan Cable
Router
Network switch or Hub

(b) Explain how a firewall would help to provide security for the LAN. [3 marks]
– Because on a Lan network, typically every computer could access each other and thus a firewall would prevent unauthorized access between each computers on the network but moreover, a firewall would prevent unwanted access from outside the network and limit the number of ports opened in that network.

(c) Suggest, with reasons, two further measures that the company should take to safeguard its data from unlawful access via the Internet. [4 marks]
1. Do not click suspicious links.
2. Only use computers for work.

Q What hardware component is needed to extend a LAN to a WAN?
– Network switch

Q Outline 3 key differences between a Switch and a Router.
– A router stores and use IP addresses while a switch stores MAC addresses.
– A router lets the network access to outside while the switch is located after the router and only packet routes to each devices connected to it.
– a switch connects multiple devices to create a network, a router connects multiple switches, and their respective networks, to form an even larger network.

Q What is the key difference between a HUB and a Switch?
– A hub just disperse the packets received to all the ports while a switch directly finds and sends the data to the destination.

Q We looked at hardware components to set up a LAN what are the hardware components need to set up WLAN
Wireless router
Network card

[ArinN_]

A bank is rolling out a new payroll system to replace a system that is no longer supported.

A) Discuss reasons why the system may not be supported by the original vendor.
– Due to reasons like compatibility, ease of use, times took to learn about the new system, etc.

B) The waterfall approach is very rigid. Can you suggest another approach that will provide end users and other stakeholders better insight to how the new system will function at an earlier stage.
– Spiral Approach

B1) Describe the 6 stages of this approach. In your view which stage is the most important and why

1. Identification: In this phase, there is continuous communication between the client and the development team in order to gather as much information as possible.
2. Design: The design stage involves architectural design, design of modules, physical product design, and final design.
3. Construct: In this stage, the actual software product is developed and while the design is being developed a Proof of Concept is made to get customer feedback.
model is developed and sent to the customer for feedback.
4. Evaluation and Risk analysis: This stage involves identifying, estimating, and monitoring the technical feasibility and management risks. At the end of each iteration, the customer tests the software and provides
evaluation.

B2) From a system development viewpoint under what circumstances would you recommend the use of the Waterfall method
– The waterfall method is the best to use when the customer’s requirements are rigid and well understood.

C) Testing is carried out to ensure the final system meets the original requirements.

C1) What is the difference between beta and alpha testing
– Beta testing is when the testing process is conducted by users while alpha testing is conducted by developers.

C2) What is the difference between black box and white/glass box testing
– Black-box testing tests the total output and input as well the UI of the system which is usually conducted by the end-user. White box testing tests specific codes and their functions by other developers.

C3) Who would carry out white box testing?
– The developers

C4) Can end users carry out white box, explain your answer.
– Yes, but only if the end users have enough knowledge about programming and past experiences building projects.

D) The bank has still to decide on the best approach to setting the new payroll system live, what advice would you give them. Their main requirement is that everyone gets paid even if the new system fails.

D1) List the alternative approaches to making a system live and discuss the advantages and possible pitfalls of each
– Direct Changeover
Disadvantages: If the system fails and there is no backup all data will be lost
Advantages: The form of change is very fast in terms of time and it is also cost-effective to do.

– Pilot
Disadvantages: The changeover is time-consuming and there is still a risk of data loss.
Advantages: It is cost-effective and if an area within the system fails, the rest of the system won’t be affected thus there is only limited data loss.

– Phased changeover
Disadvantages: Extremely time-consuming.
Advantages: Very limited data loss and limited risk of failure since small parts of the system are implemented at a given time.

– Parallel
disadvantages: It requires a large storage capacity to accommodate both systems, and can be expensive and time-consuming.
advantages: very less to no risk of data loss and if the system fails the old system is still running. this method is recommended for crucial systems.

D2) Which implementation method would you advise the Bank and why?
– Probably a pilot system because they can test out different locations and vendors to see what works. Then they can get feedback to make iterations before making the implementation to all locations. However, when they make the final implementation, the big-bang method would be recommended as it’s faster and more cost-efficient.

E) The payroll contains sensitive data should they host in-house or on the cloud and why. Discuss the merits of both and provide recommendations.
– The payroll should be hosted in-house for maximum security as storing data on a cloud can make that data more prone to data leaks and hacking thus, an in-house or local server would lessen the chance of these risks. However, an in-house server isn’t perfect as it has the risks of physical damage such as fire, water, and data corruption which if backups haven’t been made, all the data stored would be gone.

Please note for some of these there is not always a correct and wrong answer, if you are asked for a view provide it, but with justifications.

[ArinN_]

1 Of what would be involved and any possible risks in migrating to a new software system
– When migrating into a new system, data loss or data corruption could occur due to reasons like human errors and/or system errors.

2 Would you recommend developing a bespoke system explain the reason for your advice given
– Not really. If it isn’t a must I don’t think developing a bespoke system would be necessary as it would cost more than off-the-shelf software you could find online which for example, you wouldn’t try to develop a new search engine if google exists already unless you really wanted more privacy but for most people or even companies, google is good enough.

3 Discuss merits of implementing an off the shelf system VS cloud based solution.
– Off-the-shelf software would be safer in terms of storing data as it would be stored on physical drives locally while Cloud storage would cost less in terms of space needed and it would be more scalable at a lower cost. It would also be more well protected if there is a disaster/issues that could damage physicals drives as data would be stored in a cloud.

4. The existing power school is hosted in house, discuss the advantages of moving to cloud hosting and any negatives.
– An advantage of moving toward a cloud hosting system is that there would be less risk of data loss from physical damage to in-house locations such as a fire, water, etc. Also, A cloud system makes it easier to share files among users.

[ArinN_]

What is the difference between local computing and cloud or remote computing?
– Local computing is running your computer software in-house (locally) and cloud computing is running your computer software through the internet or remotely (not in house).
Why is remote hosting called cloud computing?
– Because the remote system being hosted is accessed through a cloud or the internet.
Give some examples of cloud applications/software?
– Dropbox, Google Drive, Google Docs, Youtube, Instagram, Microsoft office, etc.

Software Updates
What is the difference between a patch and a software release?
– A patch is an update with a purpose to fix bugs or other issues within the system and a software release is usually when a completely new software with new functions is released. Also usually in a release, theres going to be multiple patches.
What is the difference between manual and automatic updates?
– Manual updates require the user to physically update (usually by clicking the update button within settings), and automatic updates usually by itself without needing user approval.
What is end-of-life software?
– It’s software that will no longer be supported by its developer, meaning there would not be updates or patches.
Create a company policy for Software Updates ( what you should and should not do )
– Update reminders within the software, not by emails
– Ensure data is backed up before any major updates
– Be clear with terms of services.

End-User Training
Choose 2 methods of delivering software training and compare and contrast the advantages and disadvantages.
– Remote/Online learning:
Advantages: Can be scheduled for an ideal time and can be done anywhere.
Disadvantages: Classes may be difficult to stay focused and this method could possibly be expensive.
– Formal classes
Advantages: There is a professional that can guide you through difficult challenges and someone you can ask when you are confused or have issues.
Disadvantages: It has a scheduled time and location which not all students can attend and could miss a few classes. Additionally, self-motivation could be a problem for some people.

Data Loss
Best Practice
The Power school application at Wells is hosted in-house. A weekly backup is taken, which is stored in the cloud.
What are the dangers of this policy? Formulate a new fail-safe backup policy, money is no obstacle.
– If there is a hack or damage to the system before the weekly backup, then all data from that week can be lost.
– If the backup server locally fails, the data would be gone.
– An alternative system can be a daily backup to the cloud every few hours, and to ensure extra safety an external drive can be used to back up data alongside cloud backup or just store backups in multiple off-sites.
Will your new policy make data 100% safe?
– Yes because it is being backed up into a cloud and a physical drive at the same time, if the cloud is breached and so is the system, the physical drive would have the backed up data.

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