問21
頻出度★☆☆
炊飯器やエアコンなどの家電製品に内蔵される, 機器の特定の機能を実現するためのシステムを何というか。
平成24年度 春期 ITパスポート試験 問21
This question's explanation and your answers so far.
解説
問 21
Incorrectア
An expert system is an artificial-intelligence application system that stores the knowledge and decision rules held by experts in a particular field as a knowledge base, and then has an inference engine use them to derive judgements or advice close to those of an expert. Typical applications include medical diagnosis support, equipment fault diagnosis, and credit screening, and its purpose is to support the specialized decision-making of human beings. It is not a term for a mechanism that is built into a home appliance to realize a specific function of the device, so it is wrong. Note that fuzzy control or learning functions may indeed be used to control a rice cooker or an air conditioner, but that is merely one of the control techniques used inside an embedded system, and it does not make the form of the system an expert system.
Incorrectイ
An enterprise system is a large-scale information system that covers an entire company and supports core business operations such as accounting, human resources, production, sales, and inventory in an integrated way; ERP packages are a representative example. Its target is the business processes of an organization and its scale is that of a company, and it carries no meaning at all of a small system built into a device. What the question describes is a mechanism inside each individual device such as a rice cooker or an air conditioner, so the target, the scale, and the purpose all fail to match, and this choice is wrong.
- ウ
正解 The correct answer is ウ, “Embedded system”. An embedded system is a computer system built into the inside of a device such as a home appliance, a car, industrial equipment, or medical equipment, and designed exclusively to realize the specific function required of that device. A major characteristic is that a microcontroller (MCU), sensors, and the software that controls them are integrated into the device as one unit, so it operates without the user ever being aware that a computer is inside. Taking the rice cooker in the question as an example, an internal temperature sensor reads the temperature of the inner pot, and the built-in microcontroller finely adjusts the output of the heater according to a predetermined cooking program, automatically advancing through steps such as water absorption, heating, and steaming. In the case of an air conditioner, it reads the values of the room-temperature sensor and the human-presence sensor, and controls the rotation speed of the compressor and the direction of the louver in order to maintain the set temperature. In both cases the system is designed to reliably carry out only the processing specialized for the purpose of that device; it is not intended to be used for general purposes with the user freely adding applications, the way a PC or a server is. These two points, “built into a device” and “realizes a specific function”, match the wording of the question exactly. In an embedded system, the software that controls the operation of the device is often supplied written into ROM or flash memory, and such software is called firmware. In recent years, IoT (Internet of Things), in which such embedded devices are connected to a network and exchange information with each other, has spread widely, and embedded systems are becoming even more important as the foundational technology that supports IoT. For these reasons, the term that fits the description in the question is ウ, the embedded system.
Incorrectエ
A simplex system is a term about the redundant configuration of computer systems, referring to a configuration that has no backup line and is operated with only a single line. It is used in contrast with a duplex system, which prepares two lines and keeps one of them on standby, and a dual system, which runs the same processing in parallel on two lines and compares the results; the point at issue is the difference in configuration methods, that is, how far reliability and availability are secured. What the question asks about is the properties of being built into a device and being specialized for a function, not the topic of redundancy such as how many lines are prepared, so this term does not apply.
ここがポイント
- Embedded system — a computer system built into devices such as home appliances, cars, and industrial equipment, and designed exclusively to realize the specific function that the device needs. A microcontroller, sensors, and control software are integrated into the device as one unit, and the user is not aware that a computer is present. The control software is often supplied as firmware stored in ROM or flash memory, and it is not intended to be used by freely adding applications the way a general-purpose PC is. What develops from this by adding network connectivity so that devices exchange information with each other is IoT.
- Organize the confusing terms that end in “system” along clear axes — an expert system imitates an expert’s judgement using a knowledge base and inference (an application of artificial intelligence); an enterprise system is a large-scale information system that integrates the core business operations of an entire company (such as ERP); a simplex system is a redundant configuration with only a single line and no backup line (in contrast with duplex and dual systems). When the question text describes “where it is placed” and “what it is for”, the clues of being inside a device and having a specific function let you choose the embedded system.
用語