| Date | November 2018 | Marks available | 4 | Reference code | 18N.1.HL.TZ0.10 |
| Level | HL | Paper | 1 | Time zone | no time zone |
| Command term | Explain | Question number | 10 | Adapted from | N/A |
Question
An oil and gas company has a networked computer system for use of their employees in the Head Office.
The company also uses the internet to enable communication with employees working on exploration and production in many remote geographical areas.
The sub-sea oil and gas exploration and production unit of the company relies on thousands of kilometres of pipeline which are monitored by a computer control system which can detect leaks.
The process of detecting leaks is carried out by sensors which are continuously monitoring changes in the flow and pressure of the liquids in the pipes.
This data is processed on a computer in the office.
If any of sensor values are outside of the acceptable parameters stored on a disk in the office, the following error routines are performed:
- an alarm is sounded on the computer at the office
- an email message is sent to managers in the Head Office.
Identify one hardware security measure that will ensure that confidential data from the Head Office cannot be accessed.
Identify one software security measure that will ensure that confidential data from the Head Office cannot be accessed.
Identify one network security measure.
Explain the environmental benefit of using a computer control system to monitor the pipeline.
Explain the relationship between sensors, output transducers and processor in this situation.
Construct a system flowchart to represent the process described above.
Markscheme
Award [1] for each hardware security measure identified up to [1 max].
Retina scans;
Locked doors;
Alarms;
Protection of equipment within the building;
Award [1] for each software security measure identified up to [1 max].
Use of passwords;
Different access rights;
Encryption;
Award [1] for each network security measure identified up to [1 max].
Encryption;
UserID;
Trusted MAC addresses;
Award [3 max].
In case of leaks (depending on severity of problem) which could cause pollution (any environmental problem);
Computer control system can react quickly/turn on and off appropriate devices immediately/many times in a short interval of time/(increased efficiency);
Computer control systems are very reliable (will not be tired / will not lose concentration);
(can continue to operate reliably 24 hours a day, 7 days a week) (increased level of safety);
Control systems are reasonably cheap to run comparing to the cost involved in situations which can harm environment (and human health) (reduction of costs);
Award [4 max].
Input from flow/pressure sensors is analog;
AD convertors are used to convert this analog data into digital form;
Processor performs / logical and arithmetical / operations;
The result of processing is in digital form so it should be converted (by AD convertors) into analog form;
This signal is sent to output transducers (a device that converts energy from one form to another) (for example, alarm sounds in the office);
Award [5 max].
Award [1] for sensor input.
Award [1] for manual input and validation/configuration.
Award [1] for a disk (which is holding data).
Award [1] for a monitoring process / checking whether input values exceed the allowed range or not.
Award [1] for error routines performed.
Example 1
Example 2
