Analogical models From Wikipedia, the free encyclopedia
Analogical models are a method of representing a phenomenon of the world, often called the ‘target system’ by another, more understandable or analysable system. They are also called dynamical analogies.Contents [hide] 1 Explanation 2 Creating an analogical model 3 Mechanical analogies 4 Hydraulic analogy 5 Physiological analogies 6 Formal analogies 7 Dynamical analogies 7.1 Table of equivalents 8 Electronic circuit analogies 8.1 Hydraulic Analog 8.2 Analogue computers 9 Philosophical conundrum 10 Quotation 11 References 12 See also 13 External links
[edit] Explanation
Analogizing is the process of representing information about a particular subject (the analogue or source system) by another particular subject (the target system). A simple type of analogy is one that is based on shared properties (Stanford
Encyclopedia of Philosophy). Analogical models, also called "analog" or "analogue" models, therefore seek the analog systems that share properties with the target system as a means of representing the world. It is often practicable to construct source systems that are smaller and/or faster than the target system so that one can deduce a priori knowledge of target system behaviour. Analog devices are therefore those in which may differ in substance or structure but share properties of dynamic behaviour (Truit and Rogers, p. 1-3).“ dynamical analogies establish the analogies between electrical, mechanical, acoustical, magnetic and electronic systems ”
(Olson 1958, p.2).
For example, in analog electronic circuits, one can use voltage to represent an arithmetic quantity; operational amplifiers might then represent the arithmetic operations (addition, subtraction, multiplication, and division).Through the process of calibration these smaller/bigger, slower/faster systems are scaled up or down so that they match the functioning of the target system, and are therefore called analogs of the target system. Once the calibration has taken place, modellers speak of a one-to-one correspondence in behaviour between the primary system and its analog. Thus the behaviour of two systems can be determined by experimenting with one.
[edit] Creating an analogical model
Many different instruments and systems can be used to create an analogical model. A mechanical device can be used to represent mathematical calculations. For instance, the Phillips Hydraulic Computer used the flow of water to model economic systems (the target system); electronic circuits can be used to represent both physiological and ecological systems. When a model is run on either an analog or digital computer this is known as the process of simulation.