资源描述：
《Introduction to cellular automata》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、IntroductiontocellularautomataJean-PhilippeRennardPh.D.12/2000IntroductiontoCellularautomataThereisawealthofliteratureaboutcellularautomata,aswellasmanyInternetresources(you'llfindsomeoftheminthelinkssection).Theaimisheremuchmorelimited.Thissitebeingdevotedtolaymen,Iwill
2、contentmyselfwithansweringbothmainquestionsanypersondiscoveringCAoftenask,generallyafteraperiodofintenseperplexity:1.Whatmightthisbe?2.Whatcouldbetheapplicationsforsuchathing?Theanswertothesequestionsisunfortunatelyfarfrombeingsimple.CAareabstractconstructionswithquiteco
3、mplexpropertiesnotveryaccessible.A-HistoryThehistoryofCAdatesbacktothefortieswithStanislasUlam.Thismathematicianwasinterestedintheevolutionofgraphicconstructionsgeneratedbysimplerules.Thebaseofhisconstructionwasatwo-dimensionalspacedividedinto"cells",asortofgrid.Eachofth
4、esecellscouldhavetwostates:ONorOFF.Startingfromagivenpattern,thefollowinggenerationwasdeterminedaccordingtoneighbourhoodrules.Forexample,ifacellwasincontactwithtwo"ON"cells,itwouldswitchontoo;otherwiseitwouldswitchoff.Ulam,whousedoneofthefirstcomputers,quicklynoticedthat
5、thismechanismpermittedtogeneratecomplexandgracefulfiguresandthatthesefigurescould,insomecases,self-reproduce.Extremelysimplerulespermittedtobuildverycomplexpatterns.Onthatbasis,thefollowingquestionwasasked:cantheserecursivemechanisms(i.e.inthatcasedependingontheirownprev
6、iousstate)explainthecomplexityofthereal?Isthiscomplexityonlyapparent,thefundamentalrulesbeingthemselvessimple1?Asasideline,JohnvonNeumann,relyingonA.Turing'sworks,interestedhimselfonthetheoryofself-reproductiveautomataandworkedontheconceptionofaself-reproductivemachine,t
7、he"kinematon".Suchamachinewassupposedtobeabletoreproduceanymachinedescribedinitsprograms,includingacopyofitself2.Themostfamousofhismachinesisthemonolithoftheseries"2001SpaceOdyssey".TochangeJupiterintoastar,afirstmonolithself-reproduces,aswellasitsdescendants,thepopulati
8、onsoincreasesexponentiallytoquicklyreachthesizenecessarytorealizesuchagigantictask.UlamsuggestedvonNeum
