Unconventional computing: Difference between revisions

Revision as of 23:05, 14 February 2025

Revision as of 23:18, 14 February 2025

Line 12:

{{main|Model of computation}}

A model of computation describes how the output of a mathematical function is computed given its input. The model describes how units of computations, memories, and communications are organized.<ref>{{cite book|last=Savage|first=John E.|author-link = John E. Savage|title=Models Of Computation: Exploring the Power of Computing|year=1998|publisher=Addison-Wesley|isbn= {{Format ISBN|978-0201895391}}0-201-89539-1}}</ref> The computational complexity of an algorithm can be measured given a model of computation. Using a model allows studying the performance of algorithms independently of the variations that are specific to particular implementations and specific technology.

A wide variety of models are commonly used; some closely resemble the workings of (idealized) conventional computers, while others do not. Some commonly used models are [[register machine]]s, [[random-access machine]]s, [[Turing machine]]s, [[lambda calculus]], [[rewriting system]]s, [[digital circuit]]s, [[cellular automaton|cellular automata]], and [[Petri net]]s.

Line 30:

{{main|analog computer}}

An analog computer is a type of computer that uses ''[[analog signal]]s'', which are continuous physical quantities, to model and solve problems. These signals can be [[Electrical network|electrical]], [[Mechanics|mechanical]], or [[Hydraulics|hydraulic]] in nature. Analog computers were widely used in scientific and industrial applications, and were often faster than digital computers at the time. However, they started to become obsolete in the 1950s and 1960s and are now mostly used in specific applications such as aircraft flight simulators and teaching control systems in universities.<ref name="Johnston">{{cite book | url=https://books.google.com/books?id=iPfU_powAgAC&q=%22through%20the%201980s%22&pg=PA90 | title=Holographic Visions: A History of New Science | publisher=OUP Oxford | author=Johnston, Sean F. | year=2006 | page=90 | isbn={{Format ISBN|978-0191513886}}0-19-151388-6}}</ref> Examples of analog computing devices include [[slide rule]]s, [[nomogram]]s, and complex mechanisms for process control and protective relays.<ref name="9HtsB">{{cite web|url=https://arstechnica.com/information-technology/2014/03/gears-of-war-when-mechanical-analog-computers-ruled-the-waves/|title=Gears of war: When mechanical analog computers ruled the waves|date=2014-03-18|access-date=2017-06-14|archive-url=https://web.archive.org/web/20180908173957/https://arstechnica.com/information-technology/2014/03/gears-of-war-when-mechanical-analog-computers-ruled-the-waves/|archive-date=2018-09-08}}</ref> The [[Antikythera mechanism]], a mechanical device that calculates the positions of planets and the Moon, and the [[planimeter]], a mechanical integrator for calculating the area of an arbitrary 2D shape, are also examples of analog computing.

===Electronic digital computers===

Line 124:

{{main|Microelectromechanical systems|Nanoelectromechanical systems}}

Microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) are technologies that involve the use of microscopic devices with moving parts, ranging in size from micrometers to nanometers. These devices typically consist of a central processing unit (such as an integrated circuit) and several components that interact with their surroundings, such as sensors.<ref>{{cite book|title=Nanocomputers and Swarm Intelligence|vauthors=Waldner JB|publisher=[[ISTE Ltd|ISTE]] [[John Wiley & Sons]]|year=2008|isbn={{Format ISBN|9781848210097}}978-1-84821-009-7|place=London|page=205|author-link=Jean-Baptiste Waldner}}</ref> MEMS and NEMS technology differ from molecular nanotechnology or molecular electronics in that they also consider factors such as surface chemistry and the effects of ambient electromagnetism and fluid dynamics. Applications of these technologies include accelerometers and sensors for detecting chemical substances.<ref name = Ventra2004>{{cite book |title=Introduction to Nanoscale Science and Technology (Nanostructure Science and Technology) |publisher=Springer |___location=Berlin |date=2004|isbn=978-1-4020-7720-3 | url = https://books.google.com/books?id=mccEGiaPEJwC|author1 = Hughes, James E. Jr.|author2 = Ventra, Massimiliano Di |author3 = Evoy, Stephane |author-link2 = Massimiliano Di Ventra}}</ref>

==Chemistry approaches==