JPJC 2024 JC2 Year-End Exam H2 Computing Paper 1

Name:____________________________________ Class:_____________ JURONG PIONEER JUNIOR COLLEGE JC2 Year – End Examination 2024 COMPUTING 9569/01 Higher 2 11 September 2024 Paper 1 (Written) 3 hours Additional materials: 12-page Answer Booklet Answer all the questions. Approved calculators are allowed. You are reminded of the need for clear presentation in your answers. Answer papers will be provided with the question paper. Write your name and civics class on all the work that you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Write your answers to every question on a fresh page of paper. Approved calculators are allowed. The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 100. This document consists of 10 printed pages and 2 blank pages. [Turn over

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3 1 The in-house IT department of JP Hospital was tasked to design a data structure that can store details of patients who have registered and sought medical treatment at their Accident & Emergency (A&E) department. A patient record contains information related to the patient like the national identity number, name, gender, address etc, that can be uniquely identified by a four-digit patient number. The IT department has decided to use a zero-based array data structure that is made up of 500 ordered memory blocks of equal sizes with each memory block capable of storing at most two patient records. The four-digit patient number is used as input to a hash algorithm where the hashed result gives the location to the memory block the patient record is stored. The hash algorithm is defined as follows: 1. Divide the three rightmost digits of the four-digit patient number by 2. 2. The integer result obtained in step (1) will be the location of memory block used to store the patient’s record. Using the hashing algorithm above, the patient record with patient number 0317 will be stored in memory location 158. If a patient record is hashed to a memory block that is full, a sequential search will be performed repeatedly until a free area is found into which the patient record is written. (a) State and justify a suitable data type for the four-digit patient number. [2] (b) What is meant by a collision in this context and state the method used to resolve collisions. [2] (c) Four new patients with patient numbers 1422, 1425, 2422, 3423 are added into the system in the order given above. Given that the memory blocks are all empty before the insertion, use a diagram to show where the patient records are stored in the memory blocks of the data structure after every single successful insertion. [3] (d) Explain why a patient record can be deleted without re-organising the memory block. [2] (e) Describe how a new patient record with a unique patient number gets inserted into a memory block. Your answer should answer how collisions are handled. [4] [Turn over

4 To strengthen the security of patients’ information, JP Hospital has decided not to store the national identity number of a patient. Instead, a new patient ID that is made up of eight alphanumeric characters will be used. The leftmost three characters of the new patient ID is obtained from the result of applying the four-digit patient number to the hash algorithm given above, followed by the rightmost four-digit taken from the patient’s national identity number. The rightmost character of the new patient ID will be used as the check digit. For instance, a patient with a four-digit patient number 3425 and national identity number S1234567A has a new patient ID 21245673 as shown below: Example: Patient’s number: 3425 hash(425) = 212 Patient’s national identity number: S1234567A Therefore new patient ID with c as check digit = 2 1 2 4 5 6 7 c Check digit c can be obtained using the following rules: 1. Label every character of the new patient ID with a digit position, with the leftmost character as digit at position 8 and the rightmost character as digit at position 1 2. Except for the check digit, multiply each character digit of the new patient ID with its respective digit position 3. Sum all the multiplication results obtained in step (2) 4. Divide the product sum obtained in step (3) by 11 to obtain the remainder 5. Subtract the result obtained in step (4) from 11 6. Divide the result in step (5) by 11 and obtain the remainder as the check digit. Digit position 8 7 6 5 4 3 2 1 New Patient ID 2 1 2 4 5 6 7 c Product 16 7 12 20 20 18 14 c Sum of products = 16 + 7 + 12 + 20 + 20 + 18 +14 = 107 Remainder of 107 divided by 11 = 8 11 – 8 = 3 c = 3 MOD 11 = 3 Therefore, new patient ID = 2 1 2 4 5 6 7 3

5 (f) With workings shown clearly, find the new Patient ID for the following patients with the following details: Patient A: Patient Number = 1246, National Identity Number = S7654301Z, Patient B: Patient Number = 5323, National Identity Number = S8563222B. Using the same assignment of digit position to every character of a new patient ID, the new patient ID can be validated by first obtaining the sum of product of every digit of the new patient ID and its digit position, including the rightmost check digit. The new patient ID can only be valid if the product of sum is exactly divisible by 11. [5] (g) With workings shown clearly, validate Patient’s C ID = 21167892. [2] 2 With virtual healthcare becoming increasingly popular, medical data is also growing in volume. Health data management, or the practice of collecting, sharing, and managing data in networked medical systems has become more crucial than ever. (a) Describe how a cybercriminal can carry out a distributed denial-of-service (DDoS) attack and explain its impact. [3] (b) Explain how medical confidentiality can be breached when patient’s information gets transmitted over the internet from one device to another without any forms of encryption. [2] (c) A digitally signed message that contains patient’s medical information is to be sent over the network, (i) Describe the steps involved in the sender’s process of sending the digitally signed message. (ii) Explain how integrity and authenticity can be ensured when the receiver receives the digitally signed message. [3] [4] (d) Explain the purpose of having a backup file and an archive file in this context. [2] Patient’s information will be subjected to validation and verification whenever it is entered into a health data management system. (e) Explain the difference between data validation and data verification. [2] (f) Use one example in each instance to describe how data validation and data verification can be applied to the patient’s information before it gets keyed into a health data management system. [2] [Turn over

6 3 The IT department of JP Hospital decides to write a program using object-oriented programming language to store billing information of its patients. The following information will be stored each time a patient is billed Patient ID Name Address Contact number Cost of doctor’s consultation Cost of medicine The hospital further classifies patients into two different subsidised categories, Tier-1 subsidised patients and Tier-2 subsidised patients. Tier-1 patient subsidy offers a 40% discount off the total medical bill. Tier-1 subsidised patients need to be referred to the hospital by a local polyclinic, have an average household monthly income per person not more than $1200 and the annual value of the patient’s home must be less than $20000. If a patient has a referral