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AceDSE · Paper · 2026.07

資訊及通訊科技
Information and Communication Technology

Compulsory Systems Case with Elective Module

minutes90 minutes
marks40 marks
Attempted componentEnglish
Candidate name
Date

Sample-paper basis

sample compulsory structured pages and separate database, multimedia, networking and programming modules, with response-sheet style working

Scope of this paper

Complete the compulsory case and ONE elective diagnostic. In the full examination, follow the exact elective combination in your annual framework. SBA remains separate.

Candidate instructions

  1. Answer the compulsory case and ONE elective option.
  2. Pseudocode must be unambiguous; SQL keywords are not case-sensitive.
  3. Security answers must link threat, control and residual limitation.

Compulsory case — School wellbeing platform

25 marks
1(a)
Each daily sensor record stores student ID (8 bytes), timestamp (8 bytes), four 2-byte readings and a 1-byte status flag. Estimate storage for 1,200 students over 180 days, ignoring overhead. Give the answer in MiB.
[5 marks]
1(b)
The platform uses a web client, application server and database server. Explain two benefits of this three-tier design and one potential bottleneck.
[5 marks]
1(c)
A phishing email steals a teacher's password. Propose three controls from different stages: prevention, detection and recovery. State one limitation of each.
[7 marks]
1(d)
Write pseudocode that reads seven integer wellbeing scores (0–100), rejects and re-reads invalid values, then outputs the mean and the number below 40.
[8 marks]

Elective diagnostic

15 marks

Answer ONE option that matches your elective preparation.

Option A — Databases

2A(a)
A single table stores Booking(StudentID, StudentName, TutorID, TutorName, Slot, Room), with key (StudentID, TutorID, Slot). Identify two update anomalies and decompose it into relations in Third Normal Form, showing keys.
[8 marks]
2A(b)
Write SQL to list each TutorID and number of bookings on '2026-09-14', showing only tutors with at least 3 bookings, highest count first.
[7 marks]

Option B — Algorithm and programming

2B(a)
Trace the values printed by: x←3; FOR i←1 TO 4: x←x+i; IF x MOD 2=0 THEN OUTPUT x; ENDIF; NEXT i. Show x after every iteration.
[5 marks]
2B(b)
Write an algorithm that receives an unsorted array of positive integers and returns the second-largest distinct value, or reports that it does not exist. Use one pass and no sorting.
[10 marks]

Option C — Multimedia and networking

2C(a)
An uncompressed 1920×1080 image uses 24-bit colour. Calculate its size in MiB. A JPEG file is 0.62 MiB; find the compression ratio in the form original:compressed.
[6 marks]
2C(b)
A live class needs low delay while a recorded lecture needs high visual quality at unstable bandwidth. Compare suitable delivery/compression choices and explain how buffering, bitrate adaptation and lossy compression affect user experience.
[9 marks]

Every question and figure is original AceDSE work; official samples were used only to calibrate format, complexity and reasoning depth.
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