Obecná definice
Italsoreferstothecharacteristicsofdifferentlevelscoexistinginthesamecupofcoffee.Thehighcomplexitymeansthattherearemoretypesofsensorystimulationthatcanbefelt;whatshouldbepaidattentiontoisthesefeelingsIncludingtheafter-rhyme,itisnotnecessarilylimitedtothepresentfeelingwhendrinking.
Algoritmus
Složitost (teorie počítačové složitosti)
Computationalcomplexitytheory(Computationalcomplexitytheory)iscomputationaltheoryThefirstpartisabouttheresourcesneededtostudycomputingproblems,suchastimeandspace,andhowtosavetheseresourcesasmuchaspossible.
Themostcommonresourcesstudiedbycomputationalcomplexitytheoryaretimecomplexity(howmanystepsmustbetakentosolvetheproblem)andspacecomplexity(howmuchmemoryisneededtosolvetheproblem).Otherresourcescanalsobeconsidered,suchashowmanyparallelprocessorsareneededinparallelcomputingtosolvetheproblem.
Timecomplexityreferstothetimerequiredtocompleteanalgorithminthefieldofcomputerscienceandengineering,andisanimportantparametertomeasuretheprosandconsofanalgorithm.Thesmallerthetimecomplexity,thehighertheefficiencyofthealgorithm,andthemorevaluablethealgorithm.
Spacecomplexityreferstothestoragespacerequiredtocompleteanalgorithminthefieldofcomputerscience,whichisgenerallyafunctionofinputparameters.Itisanimportantmeasureoftheprosandconsofanalgorithm.Generallyspeaking,thesmallerthespacecomplexity,thebetterthealgorithm.WeassumethatthereisaTuringmachinetosolveacertainprobleminacertaintypeoflanguage.Xwordsbelongtothisproblem.PutXintotheinputofthisTuringmachine.ThisTuringmachineneedstosolvethisproblem.Thetotalnumberofgridsintheworkzoneiscalledspace.
Complexitytheoryisdifferentfromcomputabilitytheory.Thefocusofcomputabilitytheoryiswhethertheproblemcanbesolved,nomatterhowmanyresourcesareneeded.Asabranchofcomputationaltheory,complexitytheoryistosomeextentconsideredtobea"spear"and"shield"relationshipwithalgorithmtheory,thatis,algorithmtheoryfocusesondesigningeffectivealgorithms,whilecomplexitytheoryfocusesonunderstandingwhyForcertaintypesofproblems,thereisnoeffectivealgorithm.
Složitost (CPX):
TheconceptofcomplexitywasfirstproposedbyKolmgorov.Toputitsimply,thecomplexityofathingcanbemeasuredbythelengthofthecomputerlanguageusedtodescribeit.Itisgenerallybelievedthatthelongerthelengthofthecomputerlanguagedescribingathing,themorecomplexthething.Inthe1970s,Lempleetal.gaveadefinitiontothecomplexityofrandomsequencesintheresearchofinformationtheory.Theybelievedthatcomplexityreflectstherateatwhichnewpatternsappearinatimeseriesasitslengthincreases,andshowshowclosethesequenceistorandomness.Inthelate1980s,Kasperetal.studiedthecomplexityofrandomsequencesintheLem-Zivsense,andproposedspecificalgorithmsformeasuringthecomplexityofrandomsequences.ThecomplexitymeasureobtainedbythisalgorithmiscalledKccomplexity,anditispointedoutthatthisalgorithmissuperiortotheLyapunovexponent.Sincethecomplexityanalysismethoddoesnothavestrictrequirementsonthelengthofthesequence,itiswidelyusedinthefieldofsignalprocessing.
BeforecalculatingKc,thesequencetobeprocessedisfirstcoarse-grained,andtherandomsequenceisbinarizedhere,thatis,eachpointofthesequenceisrepresentedbyabit,soyoucanTheresearchedsignalinformationiscoarse-grainedtoforma"0,1"sequence.Assumingthatthetimetransmissionsequencetobeprocessedis{xi)(i=1,2,...,n),findtheaveragevalue.Ifxi≥averagevalue,setxi=1; ifxi
Kciscalculatedtofindthenumberofpatternscontainedinthesequencex,thespecificmethodistopassoneofthe“0,1”timeseriesAfterthestringofcharacterss(s1,s2,...,s.),addoneorastringofcharactersQtoseeifthecharacterQbelongstoSQv(SQvisobtainedbysubtractingthelastcharacterfromtheSQstring),ifitappearsThewordingofhasalreadybeenmentionedbefore,thatis,QisasubstringofsQ,thenthecharacteriscalled"copy".Itisconsideredthatthereisnonewpatterninthisprocess.Addthecharactertotheendofthestring,continuetoincreaseQ,andthenproceedJudgment;ifithasnotappearedbefore,then"insert"thischaracter,usea"·"toseparatethecharactersbeforeandafter"insert",andthinkthatanewpatternhasappeared:thenlookatallthecharactersbeforethelast"·"Tos,reconstructQ,repeattheaboveoperationuntiltheendofthesequenceandcalculatethesumofthenumberofpatternsfound.Forexample,thecomplexityofthesequence(0010)canbeobtainedbythefollowingsteps:
(1)První znak je vždy0·;
(2)S=0,Q=0,SQ=00,SQv=0,Qpatří do větySQv,0·0;
(3)s=0,Q=01,sQ=001,sQv=00,Qnepatří do větQv,0·01·;
(4)S=001,Q=0,SQ=0010,SQv=001,Qpatří ke slovuSQv,0·01·0.
Takže počet vzorů v posloupnosti je 3, tedy složitostc(4)=3.Posloupnost symbolů0000...by měla být nejjednodušší,0·000...,c(n)=2.Sčítání,jako je 010101...by měla být0.1.0101...,c(n) .
Jak je uvedeno výše, řetězec znaků je rozdělen na segmenty pomocí "·". Počet segmentů je definován jako složitostc(n). Téměř všechny sekvence "0,1" mají (n) tendenci k pevné hodnotě, což je:
limc(n)=b(n)=n/ln(n)
Takže, b(n)je progresivní chování náhodných posloupností,můžete použíttonormalizovat(n)k relativní složitosti:
C(n)=c(n)/b(n)
UsethisfunctionToexpressthecomplexchangesofthetimeseries,itcanbeseenthattheC(n)ofacompletelyrandomsequencetendsto1,whileotherregularandperiodicmotionstendto0,whilethec(n)ofanincompleterandomsequenceisbetweenthetwo.between.
Proces hrubého zrnění není nezbytně omezen na binarizaci a kvarternizaci (SunHongetal. 2002) nebo lze použít metodu zvanou jemnozrnné (ChenHongweiand ChenYazhu, 2004). Tento výsledek je přesnější než hrubozrnná složitost.