Date | May 2019 | Marks available | 3 | Reference code | 19M.1.HL.TZ0.16 |
Level | HL | Paper | 1 | Time zone | no time zone |
Command term | Explain | Question number | 16 | Adapted from | N/A |
Question
A mobile phone has been developed with its own dedicated operating system and is to be used as part of a smart home system in Singapore. The smart home system includes a centralized air conditioning system, a burglar alarm and a surveillance system.
Identify two functions of an operating system.
Explain one benefit of using a dedicated operating system on the mobile phone instead of a generic operating system.
Explain how sensors and microprocessors are used to ensure that the air conditioning system is able to maintain a constant temperature in the smart house.
The developers of the smart home system are considering developing a smart home system that uses a distributed control system to manage the temperature.
Contrast the use of a distributed air conditioning system with a centralized air conditioning system for maintaining a constant temperature in the smart home.
Markscheme
Award [2 max].
Managing memory;
Managing peripherals;
Processor management;
Scheduling;
Note to examiners: allow any valid feature of an operating system
Award [3 max].
Example 1
A dedicated operating system for a mobile phone will take up less storage space than a full-sized operating system;
This will allow the device to function more quickly;
Because it doesn’t contain features that aren’t needed;
Example 2
A dedicated operating system for a mobile phone can be customized;
Benefits the end users;
As they deal with a familiar interface;
Example 3
The dedicated OS is designed specifically for the mobile phone (hardware equipment);
This avoids compatibility issues;
While a generic operating system is designed for multiple types of hardware (which can lead to compatibility / various issues);
Award [5 max].
A desired temperature is input/pre-set by the user;
Sensors detect temperature;
And regularly/continuously send (temperature) readings to the microprocessor;
The microprocessor compares the actual readings with the pre-set (by the user) / input temperature;
If the temperature is too hot/too cold the microprocessor sends signal to actuator;
To adjust temperature (no need for complex details regarding actions of a heating/cooling system);
Note to examiners: Award [1] for evidence of the use of analogue-to-digital converter (sensors) and/or digital-to-analogue convertor(actuators).
Award [3 max].
Award [1] for each contrast/comparison, up to [3].
Centralized system allows control at a central point, which is then transmitted to the various rooms whilst distributed system allows individual control of settings at each unit / room so is more flexible // Centralized system will have same or constant temperature throughout the home whilst distributed system allows individual control of setting at each room;
Easier to control settings centrally whilst distributed system is more complicated to control remotely (due to limited / no connectivity of the control system);
Centralized system is more difficult to install due to the connectivity required between the various components whilst distributed system is easier to install due to fewer connection issues;
If a computer system / or any connection fails in the centralized system, the whole system is not able to function correctly whilst the distributed system as whole would still function correctly;
Centralized system is cheaper / has lower operational cost whilst distributed system is expensive as it requires additional hardware / software;
Centralized systems are difficult to expand whilst distributed systems are easily expandable because self-sufficient systems can be added or removed at any point in time without affecting the overall system;
Examiners report
All parts were mostly well answered although many candidates lost marks for repetition and using vague common-sense terminology, rather than technical and complete terminology.