Обща дефиниция
Italsoreferstothecharacteristicsofdifferentlevelscoexistinginthesamecupofcoffee.Thehighcomplexitymeansthattherearemoretypesofsensorystimulationthatcanbefelt;whatshouldbepaidattentiontoisthesefeelingsIncludingtheafter-rhyme,itisnotnecessarilylimitedtothepresentfeelingwhendrinking.
Алгоритъм
Сложност (теория на компютърната сложност)
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.
Сложност (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)Първият характер винаги0·;
(2)S=0,Q=0,SQ=00,SQv=0,Qпринадлежи на изречениетоSQv,0·0;
(3)s=0,Q=01,sQ=001,sQv=00,Qне принадлежи на изречениятаQv,0·01·;
(4)S=001,Q=0,SQ=0010,SQv=001,Qпринадлежи къмдуматаSQv,0·01·0.
Така че броят на шаблоните в тази последователност е 3, тоест сложността c(4)=3. Последователността от символи 0000...трябва да бъде най-простата,0·000...,c(n)=2.В допълнение, като 010101...трябва да бъде 0.1.0101...,c(n)=3 .
Както бе споменато по-горе, символният низ е разделен на сегменти с "·". Броят на сегментите е дефиниран като сложностc(n). Почти всички "0,1" последователности иматvec(n)Склонни към фиксирана стойност, което е:
limc(n)=b(n)=n/ln(n)
И така, b(n)е прогресивното поведение на случайна последователност, можете да го използвате за нормализиранеc(n)до относителна сложност:
C(n)=c(n)/b(n)
UsethisfunctionToexpressthecomplexchangesofthetimeseries,itcanbeseenthattheC(n)ofacompletelyrandomsequencetendsto1,whileotherregularandperiodicmotionstendto0,whilethec(n)ofanincompleterandomsequenceisbetweenthetwo.between.
Процесът на едрозърнеста обработка не е непременно ограничен до бинаризация и кватернизация (SunHongetal.2002) или също може да се използва метод, наречен фино зърнеста (ChenHongwei и ChenYazhu, 2004). Този резултат е по-точен от едрозърнестата сложност.