AnnalsofFuzzyMathematicsandInformaticsVolumex,No. x,(Month201y),
pp.
1xxISSN:20939310(printversion)ISSN:22876235(electronicversion)http://www.afmi.or.kr@FMIc
KyungMoonSaCo.http://www.kyungmoon.comSinglevaluedneutrosophicmultisetsRajashi
Chatterjee, P.Majumdar,
S.K.SamantaReceived2December2014;Revised17January2015;Accepted25March2015Abstract.
In this paper, we have investigated single valued
neutrosophicmultisets in detail. Several operations have been dened
on them and theirimportant algebraic properties are studied.We have
further introduced
thenotionofdistanceandsimilaritymeasuresbetweentwosinglevaluedneu-trosophic
multisets. An application of single valued neutrosophic
multisetsinmedicaldiagnosishasbeendiscussed.2010AMSClassication:
03E72,03E75Keywords:
Neutrosophicsets,SingleValuedNeutrosophicSets,Multisets,Simi-larity,SingleValuedNeutrosophicMultisets.CorrespondingAuthor:
S.K.Samanta([email protected] )1. IntroductionTheconceptof
multisetsstemmedfromtheviolationof oneof thebasicprop-ertiesof
classical settheory,
whichstatesthatanelementcanoccurinasetonlyonce. The term multiset
was rst introduced by N. G. Bruijn [8]. Multisets,
oftenreferredtoasbags, arecollectionsof
objectsthatmaycontainanitenumberofduplicates.
Multisetsaremathematicalstructuresthatcomehandyinareaslikedatabase
enquiries relatedtocomputer science. Also, indealingwiththe
prob-lemsofconstructingmathematicalmodelsforreal-lifesituations,
thedataathandaremainlyimpreciseandindeterministic. In1965,
Zadeh[31] cameupwithhisremarkabletheoryof
fuzzysetswhereheintroducedthenotionof partial belong-ingness of
anelement inaset. Later
thesetwoconceptshavebeencombinedtogenerateFuzzyMultisets[18]andwereappliedinmanyareasofcomputerscience.Aftertheintroductionof
IntuitionisticfuzzysetsbyAtanassov[4, 5] in1986, thetheoryof
Intuitionistic FuzzyMultisets [21] have beendeveloped. Onthe
otherhand, in1995, FlorentinSmarandache incorporatedthe concept of
NeutrosophicLogic [22, 23] which sprouted from a branch of
philosophy, known as Neutrosophy,meaningthestudyof
neutralitiesandgavebirthtothetheoryof
NeutrosophicRajashiChatterjeeetal./Ann. FuzzyMath. Inform.
x(201y),No. x,xxxxSets. Unlike intuitionistic fuzzysets
whichassociate toeachmember of the setadegreeof
membershipandadegreeof non-membership; , [0, 1], neutro-sophic sets
characterize each member x of the set with a truth-membership
functionTA(x), an indeterminacy-membership function IA(x) and a
falsity-membership
func-tionFA(x),eachofwhichbelongstothenon-standardunitinterval]0,
1+[. Thus,although in some cases intuitionistic sets consider a
particular indeterminacy or hes-itation margin, = 1 , neutrosophic
sets are capable of handling uncertaintyinabetter waysinceincaseof
neutrosophicsets indeterminacyis takencareofseparately. Further,
in2005, Wanget al, introducedthenotionof
Single-ValuedNeutrosophicSets(SVNS)[25],whichdierfromneutrosophicsetsonlyinthefactthat
inthe formers case, TA(x), IA(x), FA(x)[0, 1] andcanbe
appliedtosolvemanypractical problems.
Researchinvolvingsinglevaluedneutrosophicsetsandinterval
neutrosophicsets together withtheir applications arenowonfull
swing.Notionsof similarity, entropy, subsethoodmeasureetc. of
neutrosophicsetshavebeenintroducedandtheirapplicationsinseveralareas[7,17,20,28,29]arebeingexecutedbymanyauthors.Again
the theory ofsoft sets was initiated byD. Molodstov[19] in 1999 for
mod-elling uncertainty present in real life. Roughly speaking, a
soft set is a parameterizedclassicationoftheobjectsoftheuniverse.
Molodstovhadshownseveral applica-tionsof
softsetsindierentareaslikeintegration, gametheory,
decisionmakingetc. LaterMaji etal. [11] denedseveral
operationsonsoftsets. Perhapsthisisthe only theory available with a
parameterization tool for modelling uncertainty. H.AktasandN.
Cagman[1] haveshownthatfuzzysetsarespecial
casesofsoftsets.Latermanyauthors[12,13,16]havecombinedsoftsetswithothersetstogeneratehybridstructureslikefuzzysoftsets,intuitionisticfuzzysoftsets,generalizedfuzzysoftsets,vaguesoftsetsetc.
andappliedtheminmanyareaslikedecisionmaking,medical diagnosis,
similaritymeasureetc. Fewauthors[2, 3, 6, 14, 15] havealsodened the
notions of soft multisets,fuzzysoft multisets,neutrosophic soft
sets etc.VeryrecentlyS. YeandJ. Ye[30] combinedtheconceptsof
singlevaluedneutro-sophicsetsalongwiththetheoryofmultisetsandproposedanewtheoryofSingleValuedNeutrosophicMultisets(SVNMSinshort).InthispaperwehaveslightlymodiedthedenitionofSVNMSandstudieditsproperties.
The initial contributions of this paper involve the introduction of
variousnewset-theoreticoperatorsonSVNMSandtheirproperties. Later,
thenotionofsingle valued neutrosophic sets has been applied in
solving a decision making problemregardingmedicaldiagnosis.2.
PreliminariesIn this section we give the denition and some
important results regarding
singlevaluedneutrosophicsets[25]andmultisets.Denition2.1([25]). Let
Xbeaspaceof points, withagenericelement inXdenotedbyx.
AsinglevaluedneutrosophicsetAinXischaracterizedbyatruth-membershipfunctionTA,
anindeterminacy-membershipfunctionIAandafalsity-membershipfunctionFA.
ForeachpointxinX,TA(x), IA(x), FA(x)[0,
1].2RajashiChatterjeeetal./Ann. FuzzyMath. Inform. x(201y),No.
x,xxxxWhenXiscontinuous,aSVNSAcanbewrittenasA =_XT(x), I(x), F(x)
x, x XWhenXisdiscrete,aSVNSAcanbewrittenasA =n
i=1T(xi), I(xi), F(xi) xi, xi XDenition2.2([25]). Thecomplement
of aSVNSAisdenotedbyc(A) andisdenedbyTc(A)(x) = FA(x),Ic(A)(x) = 1
IA(x)andFc(A)(x) = TA(x),x X.Denition2.3([25]). ASVNSAis
containedinanother SVNSBi.e.ABiTA(x) TB(x),IA(x) IB(x)andFA(x)
FB(x), x X.Denition2.4([25]). TwoSVNSAandBaresaidtobeequal iA BandB
A.Denition 2.5 ([25]). The union of two SVNMS A and B is a SVNMS C,
written as,C= A
B,whosetruth-membership,indeterminacymembershipandfalsitymem-bershipfunctionsarerelatedtothoseofAandBasTC(x)=max(TA(x),
TB(x)),IC(x) = max(IA(x), IB(x))andFC(x) = min(FA(x), FB(x)), x
X.Denition2.6([25]). The intersection of two SVNMS A and Bis a SVNS
C, writ-tenas,C=
AB,whosetruth-membership,indeterminacymembershipandfalsitymembership
functions are related to those of Aand B as TC(x) = min(TA(x),
TB(x)),IC(x) = min(IA(x), IB(x))andFC(x) = max(FA(x), FB(x)), x
X.Denition2.7([25]). ThedierencebetweentwoSVNMSAandBis aSVNSC,
writtenas, C=AB, whosetruth-membership,
indeterminacymembershipandfalsitymembershipfunctions are relatedto
those of AandBas TC(x) =min(TA(x), FB(x)), IC(x) = min(IA(x), 1
IB(x)) and FC(x) = max(FA(x), TB(x)),x X.Denition2.8([25]).
Thetruth-favoriteof aSVNSA, denotedby A, whosetruth-membership,
indeterminacy-membership and falsity-membership functions
aredenedas TA(x) =min(TA(x) +IA(x), 1), IA(x) =0andFA(x) =FA(x),x
X.Denition2.9([25]). Thefalsity-favoriteof aSVNSA, is
aSVNSdenotedbyA, whosetruth-membership,
indeterminacy-membershipandfalsity-membershipfunctionsaredenedasTA(x)
= TA(x),IA(x) = 0andFA(x) = min(FA(x) +IA(x), 1), x X.Denition 2.10
([24]). Let U= {x1, x2, ..., xn} be the universal set. A crisp bag
ormultiset Mof Uis characterized by a function CM (.), (CM: U N)
correspondingtoeachx U , knownasthecountfunction.
AmultisetMisexpressedasM=_k1x1,k2x2,
...,knxn_suchthatxiappearskitimesinM.3RajashiChatterjeeetal./Ann.
FuzzyMath. Inform. x(201y),No. x,xxxx3.
SingleValuedNeutrosophicMultisetsThe notion of single valued
neutrosophic multisets were rst dened in [30]. Herethe three count
functions are real valued but in this paper we have redened the
no-tion of SVNMS with positive integer valued count functions for
the sake of practicaluse.Denition3.1.
ASingleValuedNeutrosophicMultiset(SVNMS)A,
denedonauniverseXissuchthatcorrespondingtoeachelementof
thesetthereexistsafunction, namely, the count functionCf: XN,
whichdenotes the numberof timesthatparticularelementoccursintheset,
suchthateachx
Xischarac-terizedbythreesequencesoflengthsCf(x),namely,atruth-membershipsequence_T1A(x),
T2A(x), ..., TkA(x)_, an indeterminacy-membership sequence_I1A(x),
I2A(x), ..., IkA(x)_andafalsity-membershipsequence_F1A(x), F2A(x),
..., FkA(x)_.Whentheuniverseunder considerationX= {x1, x2, ...,
xn}, is discrete,
aSingleValuedNeutrosophicMultisetAoverXisrepresentedasA=n
i=1__T1A(xi), T2A(xi), ..., TkiA(xi)_,_I1A(xi), I2A(xi), ...,
IkiA(xi)_,_F1A(xi), F2A(xi), ..., FkiA(xi)__wheretheelementxi
Xisrepeatedki= Cf(xi)timesinX.Remark3.2.
Thetruth-membershipsequenceisalwaysadecreasingsequenceofmembershipvalueswhereastheindeterminacy-membershipandfalsity-membershipsequencesaresuchthattheycanassumethemembershipvaluesinanyorderand0
TrA(xi) + IrA(xi) + FrA(xi) 3, xi X, i=1, 2, ..., nandr=1, 2, ...,
ki.
ThishasbeendonetokeepparitywiththedenitionsofFuzzyandIntuitionisticfuzzymultisets.Denition3.3.
Thelengthof anelement xi Xof
asingle-valuedneutrosophicmultisetA,denedonthesetX,isdenedasl(xi:
A) = Cf(xi), i = 1, 2, ..., n.Denition 3.4. The cardinality of a
single-valued neutrosophic multiset A is denedasCard(A) =
ni=1
l(xi:A)j=1_TjA(xi) +IjA(xi)_,xi X,i = 1, 2, ..., n.Example3.5.
Suppose X= {x1, x2, x3} denotes three shirts displayed for sale in
aparticularshop.
Wenowsetforthtoregistertheopinionofadomainofcustomersabout the
quality of shirts based on whether the shirts are made up of good
fabric,a level of indeterminacy on the part of the customers and
whether they feel that theshirtismadeupofanotsogoodfabric.
Basedontheopinionofthedomainofcustomersconcerned,asingle-valuedneutrosophicmultisetcanbedenedonXasfollows:A
= (0.6, 0.4) , (0.5, 0.3) , (0.2, 0.3) /x1 +0.2, 0.4, 0.7 /x2+(0.8,
0.6, 0.5) , (0.2, 0.2, 0.3) , (0.1, 0.3, 0.4) /x3Also,l (x1: A) =
2,l (x2: A) = 1,l(x3: A) = 3andCard(A) = 5.Denition3.6.
Anabsolutesingle-valuedneutrosophicmultisetAis aSVNMSwhereTi(x) =
1,Ii(x) = 1andFi(x) = 0, x X,i = 1, 2, ..., l(x :A).Denition3.7.
Anull single-valuedneutrosophicmultisetisaSVNMSwhereTi(x) = 0,Ii(x)
= 0andFi(x) = 1, x X,i = 1, 2, ..., l(x
:).4RajashiChatterjeeetal./Ann. FuzzyMath. Inform. x(201y),No.
x,xxxx4.
OperationsoverSingleValuedNeutrosophicMultisetsInthissectionwehavedenedseveral
settheoreticandalgebraicoperationsonSVNMS.Theseoperationsaredierentfromtheoperationsthathavebeendenedin
[30]. Moreover, in our case the behaviour of indeterminacy
membership is similarto the behaviour of truth membership whereas
in [30] the indeterminacy
membershipissimilartothebehaviouroffalsitymembership.4.1.
Set-theoreticoperationsoverSinglevaluedneutrosophicmultisets.Denition4.1.
ASVNMSAis saidtobe containedinanother SVNMSBixi X,i = 1, 2, ...,
n,(i)l(xi: A) l(xi: B)(ii)TrA(xi) TrB(xi)(iii)IrA(xi)
IrB(xi)(iv)FrA(xi) FrB(xi), xi X, i = 1, 2, ..., nandr = 1, 2, ...,
l(xi: A).Denition4.2.
TwoSVNMSAandBaresaidtobeequalitheyaresubsetsofoneanother.Remark4.3.
LetAandBbetwoSVNMSovertheuniverseX.
Inordertocarryoutanyoperation(set-theoreticoralgebraic)betweenAandBitisveriedatrstwhetherl(xi:
A)=l(xi: B), xi X. If l(xm: A) =l(xm: B)foranyxm
Xthenwithoutanylossof generality, asucientnumberof
0sareappendedwiththetruth-membershipandtheindeterminacymembershipvalues
andasucientnumberof1sareappendedwiththefalsity-membershipvaluesrespectivelytothesequences
of smaller lengththerebymakingthelengths equal
andfaciltatingtheexecutionofoperations.Example4.4.
SupposetwoSVNMSAandBaregivenby,A = 0.5, 0.4, 0.4 /x1 +(0.3, 0.2) ,
(0.5, 0.4) , (0.6, 0.7) /x2 +0.8, 0.3, 0.2 /x3B= (0.8, 0.6) , (0.4,
0.5) , (0.1, 0.3) /x1 +(0.5, 0.4) , (0.7, 0.7) , (0.5, 0.3) /x2
+0.9, 0.5, 0.2 /x3HereA B.Denition4.5.
TheunionoftwoSVNMSAandBoverX, denotedbyAB, isa SVNMS over Xwhose
truth-membership,indeterminacy-membership and
falsity-membershipvaluesaregivenbyTrAB(xi) = max(TrA(xi),
TrB(xi))IrAB(xi) = max(IrA(xi), IrB(xi))FrAB(xi) = min(FrA(xi),
FrB(xi))xi X,i = 1, 2, ..., n;r = 1, 2, ..., lwherel = max{l(xi:
A), l(xi: B)}.Denition4.6. The intersectionof twoSVNMSAandBover X,
denotedbyA B, isaSVNMSoverXwhosetruth-membership,
indeterminacy-membershipandfalsity-membershipvaluesaregivenbyTrAB(xi)
= min(TrA(xi), TrB(xi))IrAB(xi) = min(IrA(xi), IrB(xi))FrAB(xi) =
max(FrA(xi), FrB(xi))xi X,i = 1, 2, ..., n;r = 1, 2, ..., lwherel =
max{l(xi: A), l(xi: B)}.5RajashiChatterjeeetal./Ann. FuzzyMath.
Inform. x(201y),No. x,xxxxExample 4.7. Let two SVNMS A and B, dened
over the universe X= {x1, x2, x3}begivenby,A = (0.5, 0.3) , (0.1,
0.1) , (0.7, 0.8) /x1 +(0.7, 0.68, 0.62) , (0.3, 0.45, 0.5) ,
(0.34, 0.28, 0.49) /x2+(0.67, 0.5, 0.3) , (0.2, 0.3, 0.4) , (0.4,
0.5, 0.7) /x3B= 0.75, 0.2, 0.15 /x1 +(0.43, 0.37, 0.28, (0.5, 0.2,
0.3) , (0.7, 0.8, 0.9)) /x2+(1.0, 0.86, 0.79) , (0.01, 0.1, 0.2) ,
(0.0, 0.3, 0.2) /x3 A B= (0.75, 0.3) , (0.2, 0.1) , (0.15, 0.8)
/x1+(0.7, 0.68, 0.62) , (0.5, 0.45, 0.5) , (0.34, 0.28, 0.49)
/x3+(1.0, 0.86, 0.79) , (0.2, 0.3, 0.4) , (0.0, 0.3, 0.2)
/x3Denition 4.8. The truth-favorite of a SVNMS A, denoted by A, is
a SVNMS andischaracterizedbythetruth-membership,
indeterminacy-membershipandfalsity-membershipvalueswhicharerespectivelydenedasTrA(xi)
= min(TrA(xi) +IrA(xi), 1)IrA(xi) = 0FrA(xi) = FrA(xi)xi X, i = 1,
2, ..., n; r = 1, 2, ..., lwherel = max{l(xi: A), l(xi:
B)}.Denition4.9. Thefalsity-favoriteofaSVNMSA,denotedby
A,isaSVNMSand is characterized by the truth-membership,
indeterminacy-membership and
falsity-membershipvalueswhicharerespectivelydenedasTrA(xi) =
TrA(xi)IrA(xi) = 0FrA(xi) = min(FrA(xi) +IrA(xi), 1)xi X,i = 1, 2,
..., n;r = 1, 2, ..., lwherel = max{l(xi: A), l(xi:
B)}.Example4.10. ConsideringtheSVNMSAofexample4.7wehave,A = (0.6,
0.4) , (0.0, 0.0) , (0.7, 0.8) /x1+(1.0, 1.0, 1.0) , (0.0, 0.0,
0.0) , (0.34, 0.28, 0.49) /x2+(0.87, 0.8, 0.7) ,(0.0, 0.0, 0.0)
,(0.4, 0.5, 0.7) /x3A = (0.5, 0.3) , (0.0, 0.0) , (0.8, 0.9)
/x1+(0.7, 0.68, 0.62) , (0.0, 0.0, 0.0) , (0.64, 0.73, 0.99)
/x2+(0.67, 0.5, 0.3) , (0.0, 0.0, 0.0) , (0.6, 0.8, 1.0)
/x3Proposition4.11. It hasbeenobservedthat
single-valuedneutrosophicmultisetssatisfythefollowingpropertiesunderset-theoreticoperations:1.
CommutativeProperty(i)A B= B A(ii)A B= B A2.
AssociativeProperty(i)A (B C) = (A B) C(ii)A (B C) = (A B)
C6RajashiChatterjeeetal./Ann. FuzzyMath. Inform. x(201y),No.
x,xxxx3. IdempotentProperty(i)A A = A(ii)A A = A(iii) A = A(iv) A =
A4. AbsorptiveProperty(i)A (A B) = A(ii)A (A B) = A5. (i)AA
=A(ii)AA = A(iii)A = A(iv)A =Proof. Theproofsarestraight-forward.
4.2. AlgebraicOperationsoverSVNMS.Denition4.12. The addition
between two SVNMS A and Bover the universe X,denotedbyA B,
isaSVNMSoverX, whosetruth-membership,
indeterminacy-membershipandfalsity-membershipvaluesaredenedasTrAB(xi)
= TrA(xi) +TrB(xi) TrA(xi).TrB(xi)IrAB(xi) = IrA(xi) +IrB(xi)
IrA(xi).IrB(xi)FrAB(xi) = FrA(xi).FrB(xi)xi X,i = 1, 2, ..., n;r =
1, 2, ..., l.Denition4.13.
ThemultiplicationbetweentwoSVNMSAandBovertheuni-verse X, denoted by
AB, is a SVNMS over X, whose truth-membership,
indeterminacy-membershipandfalsity-membershipvaluesaredenedasTrAB(xi)
= TrA(xi).TrB(xi)IrAB(xi) = IrA(xi).IrB(xi)FrAB(xi) = FrA(xi)
+FrB(xi) FrA(xi).FrB(xi)xi X,i = 1, 2, ..., n;r = 1, 2, ...,
l.Example4.14.
LettheSVNMSunderconsiderationbethosestatedinexample4.7ThenwehaveAB=
(0.875, 0.3) , (0.28, 0.1) , (0.105, 0.0) /x1+(0.829, 0.7894,
0.7264) , (0.65, 0.56, 0.65) , (0.238, 0.224, 0.441) /x2+(1.0,
0.93, 0.853) , (0.208, 0.37, 0.52) , (0.0, 0.15, 0.14) /x3AB=
(0.375, 0.0) , (0.02, 0.0) , (0.745, 0.8) /x1+(0.301, 0.252, 0.174)
, (0.15, 0.09, 0.15) , (0.802, 0.856, 0.949) /x2+(0.67, 0.43,
0.237) , (0.002, 0.03, 0.08) , (0.4, 0.65, 0.76) /x35.
ProposeddistancemeasurebetweentwoSVNMSInthissection, thenotionof
distance, denotedbyd(A, B), ingeneral,
betweentwoSVNMSAandBdenedovertheuniverseX= {x1, x2, ...,
xn}hasbeenpro-posedinthesenseofHamming, NormalizedHamming,
EuclideanandNormalizedEuclidean.7RajashiChatterjeeetal./Ann.
FuzzyMath. Inform. x(201y),No. x,xxxxSupposethat,li= maxi{l(xi: A),
l(xi: B)}andL = maxi{li},i = 1, 2, ..., n.Denition5.1.
TheHammingdistancebetweenAandBisgivenby,dN(A, B) =n
i=1li
r=1(|TrA(xi) TrB(xi)| +|IrA(xi) IrB(xi)| +|FrA(xi)
FrB(xi)|)Denition5.2.
TheNormalizedHammingdistancebetweenAandBisgivenby,lN(A, B)
=13nLn
i=1li
r=1(|TrA(xi) TrB(xi)| +|IrA(xi) IrB(xi)| +|FrA(xi)
FrB(xi)|)Denition5.3.
TheEuclideandistancebetweenAandBisgivenby,eN(A, B) =_n
i=1li
r=1_TrA(xi) TrB(xi)2+IrA(xi) IrB(xi)2+FrA(xi)
FrB(xi)2_Denition5.4.
TheNormalizedEuclideandistancebetweenAandBisgivenby,qN(A, B)
=_13nLn
i=1li
r=1_TrA(xi) TrB(xi)2+IrA(xi) IrB(xi)2+FrA(xi)
FrB(xi)2_Remark5.5.
Ithasbeenobservedthattheproposeddistancemeasuresasstatedabovesatisesthefollowingproperties:(i)dN
(A, B)[0, 3nL](ii)lN (A, B)[0, 1](iii)eN (A, B)_0,3nL_(iv)qN (A,
B)[0, 1]Proof. Theproofsarestraight-forward. Proposition 5.6. It
has been observed that in general, whatever might be the
notioninwhichthe distance betweenany twoSVNMSbe dened, the distance
measured (A,
B)betweenanytwoSVNMSAandBsatisesthefollowingproperties:(i)d (A, B)
0andtheequalityholdsiA = B.(ii)d (A, B) = d (B, A)(iii)d (A, B) d
(A, C) +d (B, C),whereCisaSVNMSoverX.Proof. Theproofs of (i)
and(ii) arestraightforward. Wegivetheoutlineof
theproofsof(iii)only.ConsiderthreearbitrarySVNMSA, BandC. Thenforr
= 1, 2, ..., liwehaveTrA(xi) TrB(xi) =TrA(xi) TrC(xi) +TrC(xi)
TrB(xi)TrA(xi) TrC(xi)+TrB(xi)
TrC(xi)Similarlyitcanbeshownthat,IrA(xi) IrB(xi)IrA(xi)
IrC(xi)+IrB(xi) IrC(xi)FrA(xi) FrB(xi)FrA(xi) FrC(xi)+FrB(xi)
FrC(xi)8RajashiChatterjeeetal./Ann. FuzzyMath. Inform. x(201y),No.
x,xxxxHenceitfollowsthat,
ni=1
lir=1_TrA(xi) TrB(xi)+IrA(xi) IrB(xi)+FrA(xi) FrB(xi)_
ni=1
lir=1_TrA(xi) TrC(xi)+IrA(xi) IrC(xi)+FrA(xi) FrC(xi)_+
ni=1
lir=1_TrB(xi) TrC(xi)+IrB(xi) IrC(xi)+FrB(xi)
FrC(xi)_Again,weseeTrA(xi) TrB(xi)2=TrA(xi) TrC(xi) +TrC(xi)
TrB(xi)2TrA(xi) TrC(xi)2+TrB(xi) TrC(xi)2SimilarlywehaveIrA(xi)
IrB(xi)IrA(xi) IrC(xi)+IrB(xi) IrC(xi)FrA(xi) FrB(xi)FrA(xi)
FrC(xi)+FrB(xi) FrC(xi)andhence,
ni=1
lir=1_TrA(xi) TrB(xi)2+IrA(xi) IrB(xi)2+FrA(xi) FrB(xi)2_
ni=1
lir=1_TrA(xi) TrC(xi)2+IrA(xi) IrC(xi)2+FrA(xi) FrC(xi)2_+
ni=1
lir=1_TrB(xi) TrC(xi)2+IrB(xi) IrC(xi)2+FrB(xi)
FrC(xi)2_Thustheproofsfollowautomaticallyfromtheaboveresults.
Remark5.7.
Fromtheaforementionedobservationsitcanbeconcludedthattheproposed
notion of distance measures actually dene metrics over the set of
all
single-valuedneutrosophicmultisetsandhenceifNmdenotesthecollectionofallSVNMSoverauniverseXthen(Nm,
d)denesametricspaceoverX.Example 5.8. Let us consider the SVNMS A
and Bas stated in example 4.7. ThenwehavedN (A, B) = 7.83,lN (A, B)
= 0.29,eN (A, B) = 1.772andqN (A, B) = 0.3418.6.
SimilarityMeasurebetweentwoSVNMSInthissectionthenotionof
similaritymeasurebetweentwoSVNMShasbeenstated.
ThevarioustypesofsimilaritymeasuresbetweentwoSVNMSareproposedasfollows:Denition6.1.
TheDistanceBasedSimilarityMeasureisdenedas,Sd (A, B) =11 + d (A,
B)wherethedistancemeasurecanbetakeninanyof
themethodsasmentionedinSection5.Denition6.2.
TheSimilarityMeasurebasedonmembershipdegreesisdenedas,Sm (A,
B)=
ni=1
lir=1{min(TrA(xi), TrB(xi)) + min(IrA(xi), IrB(xi)) +
min(FrA(xi), FrB(xi))}
ni=1
lir=1_max_TrA(xi), TrB(xi)_+ max_IrA(xi), IrB(xi)_+ max_FrA(xi),
FrB(xi)__9RajashiChatterjeeetal./Ann. FuzzyMath. Inform.
x(201y),No. x,xxxxRemark6.3. Insomecases,
especiallywhiledealingwithreal lifeproblems, theelements of the
universe under consideration are associated with weights in order
tospecifythevaryingdegreesofimportanceoftheelementsathand.
Inthiscasewehave considered this possibility and accordingly the
similarity measure between
twoSVNMShavebeendenedwheretheuniverseoverwhichthesetsaredenedhaveweightsassociatedtoitsconstituentelements.Denition6.4.
Theweightedsimilaritymeasureinthesenseof Majumdar
andSamanta[17]isdenedas,Sw (A, B)=
ni=1 wi_
lir=1{TrA(xi).TrB(xi)+IrA(xi).IrB(xi)+FrA(xi).FrB(xi)}_
ni=1
wi[(TrA(xi)2+IrA(xi)2+FrA(xi)2).(TrB(xi)2+IrB(xi)2+FrB(xi)2)]._1
ni=1 wi_where0 wi 1,i=1, 2, ...,
nandwiaretheweightsassociatedwiththexisrespectivelywherexi
X.Denition 6.5. The proposed weighted similarity measure in the
sense of
DengfengandChuntian[9]isdenedasfollows:LetAbeaSVNMSoverauniverseX.
WedeneafunctionA: X [0, 1]as,A(x) =
lr=1{TrA(x) + IrA(x) + (1 FrA(x))}3lwherel = l(x :
A)isthelengthofanelementx X.Dene the weightedsimilaritymeasure
betweentwoSVNMSAandBover thesameuniverseXas,S
w (A, B) = 1 p
ni=1 wi |B(xi) A(xi)|p
ni=1 wiwhere0 wi 1, i =1, 2, ...,
nandwiaretheweightsassociatedwiththexisrespectivelywherexi
X.Herepisapositiveintegercalledthesimilaritydegree.Example6.6.
WeconsidertheSVNMSAandBasstatedinexample4.7.
ThentakingintoconsiderationtheresultlN (A, B) =
0.29fromexample5.8wehave,Sd (A, B) = 0.775andSm (A, B) =
0.485.Proposition6.7. 1.
Thedistancebasedsimilaritymeasuresatisesthefollowingproperties:(i)0
Sd (A, B) 1andequalityoccursiA = B(ii)Sd (A, B) = Sd (B,
A)(iii)ForA B C,Sd (A, C) Sd (A, B) Sd (B, C)2.
Thesimilaritymeasurebasedonmembershipdegreessatisesthefollowingprop-erties:(i)0
Sm (A, B) 1andequalityoccursiA = B(ii)Sm (A, B) = Sm (B,
A)10RajashiChatterjeeetal./Ann. FuzzyMath. Inform. x(201y),No.
x,xxxx(iii)ForA B C,Sd (A, C) Sd (A, B) Sd (B, C)3.
Theweightedsimilaritymeasuressatisfythefollowingproperties:(a).(i)0
Sw (A, B) 1andequalityoccursiA = B(ii)Sw (A, B) = Sw (B, A)(b).(i)0
Sw(A, B) 1andequalityoccursiA = B(ii)Sw(A, B) = Sw(B, A)(iii)ForA B
C,Sw(A, C) Sw(A, B) Sw(B,
C)(iv)CorrespondingtoanytwoSVNMS,foranascendingsequenceofintegralvaluesofpadecreasingsequenceofsimilaritymeasuresisobtained.Proof.
Weonlyprove3(b)(iii)and3(b)(iv)sincetheremainingproofsarestraight-forward.LetA
B Cthenitiseasytoprovethat{C(xi) A(xi)} {B(xi) A(xi)}sinceTrC(xi)
TrB(xi),IrC(xi) IrB(xi)andFrC(xi) FrB(xi), xiX,i = 1, 2, ...,
nandr= 1, 2, ..., max{l (xi: B) , l (xi: C)}.Thus,
l(xi:C)r=1_TrC(xi) +IrC(xi) +_1 FrC(xi)__
l(xi:B)r=1_TrB(xi) +IrB(xi) +_1 FrB(xi)__andhence,{C(xi) A(xi)}
{B(xi) A(xi)} = {C(xi) B(xi)} 0.So,|{C(xi) A(xi)}|p |{B(xi)
A(xi)}p|
ni=1wi|{C(xi) A(xi)}|p
ni=1wi|{B(xi) A(xi)}|pSw (A, C) Sw (A,
B)Similarly,itcanbeshownthatSw (A, C) Sw (B, C).Next, suppose that
for aparticular pN, ai= |B(xi) A(xi)| andqi=wi,i = 1, 2, ...,
n.Thus,p
ni=1 wi |B(xi) A(xi)|p
ni=1 wi=
ni=1 qi (ai)p
ni=1 qi1p= f(p), say.Hence, f(p) is a power meanfunction[10]
therebybeing strictlymonotonicallyincreasinginnaturei.e. forp1, p2
Nwithp1< p2, f(p1) < f(p2)._ni=1qi (ai)p1
ni=1qi_1p1 1 _ni=1qi (ai)p2
ni=1qi_1p211RajashiChatterjeeetal./Ann. FuzzyMath. Inform.
x(201y),No. x,xxxxThis proves the fact that as p increases, the
value of the similarity measureSw (A,
B)decreasesandhenceitmaybeconcludedthatforasequenceofascendingintegralvalues
for pweobtainadecreasingsequenceof similaritymeasures
betweentwoSVNMSAandB,whichcompletestheproof. Remark6.8. Fromthe
aforementionedproperties it is clear that the weightedsimilarity
measure Sw (A, B) in the sense of [17] is not an actual similarity
measure inthe actual sense of the term since it does not satisfy
all the properties of the axiomaticdenitionof asimilaritymeasure
[26]. Wethus termthis particular measure
ofsimilarityaweightedquasi-similaritymeasure.7.
AnapplicationofSinglevaluedneutrosophicmultisetsinmedicaldiagnosisSince
real-life situations involve uncertainties, while constructing a
mathematicalmodel ofpractical
importanceweneedtoincorporatevariablesthatcandeal
withuncertainties. Inthis
sectionwestateanexamplewithaviewtoshowhowthetheoryofsingle-valuedneutrosophicmultisetscanbeusedindiagnosingamedicalcondition.Afeverisoneof
themostcommonmedical
signsanditischaracterizedbyanelevationofbodytemperatureabovethenormal
rangeof97.7F 98.5F. Itcanbecausedbymanymedical
conditionsrangingfrombenigntopotentiallyserious.Besidesanelevatedbodytemperaturethereareadditionalsymptomssuchasshiv-ering,
sweating, loss of appetiteetc. whichareassociatedwithfever.
Moreover,there are specic patterns of temperature changes during a
fever according to whichafever maybeclassiedas Continuous fever,
Pel-Ebsteinfever, Remittent feverand Intermittent fever, which in
turn may be classied into Quotidian fever,
TertianfeverandQuartanfever.
Thesefeverpatternsalongwiththeassociatedsymptomsaidinthediagnosisofaparticulardisease.Consider
the case of apersonprimarilydiagnosedwithfever
associatedwithshivering, headache, muscleandjointache, cough,
runningnoseaccompaniedwithsneezing, lossof appetite,
chestpainandfatigue. Theassociatedsymptomsthatare prominent in the
person hint at the fact that the person might be suering
fromTuberculosis,InuenzaorCommonCold.Tuberculosisisaninfectiousdisease,
typicallyof thelungsandischaracterizedbyremittent fever
accompaniedbybadcough, at times accompaniedbyblood,paininthe chest,
fatigue, loss of appetite, chills andnight sweating. Inuenzaor
Fluis characterizedbyremittent fever, extremechills, shivering,
cough,
nasalcongestionandrunnynoseaccompaniedbysneezing,bodyache,particularlyinthejoints,fatigueandheadache.
Ontheotherhand,CommonColdischaracterizedbyremittentfeveraccompaniedbyrunnynose,shivering,cough,bodyache,headacheandsneezing.Forthesakeofdiagnosis,thepatientiskeptundersupervisionforadayandhisfeverpatternalongwiththeothersymptomsaremonitoredthrice,
atintervalsof8 hrs, starting from 6:00 hrs in the morning, then at
14:00 hrs and nally at 22:00 hrs.12RajashiChatterjeeetal./Ann.
FuzzyMath. Inform. x(201y),No.
x,xxxxThemedicalndingsofthepatientarerepresentedinatabularformasfollows:SymptomsTimings
T Sh Sw H MJ C LA CP F RNS6:00hrs 97.5F - - - m m m - m m14:00hrs
100F m - m m m m - m m22:00hrs 101.2F h - m m m m - m mTable7.1.
Tablerepresentingthemedicalndingsofthepatient.HereT, Sh, Sw, H, MJ,
C, LA, CP, FandRNSdenotebodytemprature, shiv-ering, sweating,
headache, muscle and joint pain, cough, loss of appetite, chest
pain,fatigueandrunningnosewithsneezingrespectivelyandthesesymptomsaltogetherconstitute
the univrsal set. On the other hand, the symbols m and h are
abbrevi-ations for moderate and high respectively which denote the
qualitative intensityoftheelementsoftheuniversalset.The above
ndings of the patient can be summarized and represented with the
helpof a SVNMS, denoted by Pf(symbolic representation for the
patients ndings) overtheabovementioneduniverseasfollows:A = (0,
0.5, 0.7) , (0.2, 0.1, 0) , (0.9, 0.1, 0) /T+(0, 0.5, 0.9) , (0.1,
0.1, 0) , (1, 0.3, 0) /Sh+(0, 0, 0) , (0.1, 0, 0) , (0.9, 0.9, 1)
/Sw +(0, 0.5, 0.4) , (0.1, 0.2, 0.2) , (0.8, 0.3, 0.3) /H+(0.5,
0.5, 0.5) , (0, 0.1, 0) , (0.2, 0.3, 0.4) /MJ+(0.55, 0.5, 0.4) ,
(0.2, 0, 0) , (0.5, 0.4, 0.5) /C+(0.5, 0.5, 0.45) , (0.2, 0.2, 0.1)
, (0.4, 0.3, 0.4) /LA+(0, 0, 0) , (0.1, 0.1, 0) , (0.8, 0.9, 0.9)
/CP+(0.58, 0.5, 0.5) , (0.3, 0.2, 0.1) , (0.3, 0.3, 0.4) /F+(0.5,
0.4, 0.4) , (0.1, 0.1, 0) , (0.2, 0.3, 0.4)
/RNSSupposethestandardsymptomaticcharacteristicsof
thediseasesarerepresentedbythefollowingSVNMSas,TB= (0, 0.5, 0.6) ,
(0, 0.1, 0) , (0.9, 0.4, 0.2) /T+(0.6, 0.6, 0.5) , (0.1, 0.1, 0) ,
(0.2, 0.1, 0.1) /Sh+(0.5, 0.5, 0.7) , (0.1, 0.2, 0.1) , (0.4, 0.3,
0.1) /Sw +(0, 0, 0) , (0, 0.1, 0) , (0.8, 0.8, 0.9) /H+(0, 0, 0) ,
(0.1, 0.1, 0.1) , (0.9, 1, 0.9) /MJ+(1, 0.9, 0.9) , (0.1, 0, 0.1) ,
(0, 0, 0.1) /C+(0.6, 0.6, 0.5) , (0.3, 0.2, 0.2) , (0.4, 0.5, 0.4)
/LA+(0.7, 0.6, 0.6) , (0.2, 0.1, 0.1) , (0.2, 0.3, 0.1) /CP+(0.5,
0.4, 0.3) , (0.4, 0.4, 0.3) , (0.4, 0.5, 0.3) /F+(0.4, 0.3, 0.3) ,
(0.3, 0.3, 0.2) , (0.5, 0.4, 0.5) /RNSInf= (0.8, 0.7, 0.7) , (0,
0.1, 0.1) , (0.1, 0.1, 0.2) /T+(0.9, 0.8, 0.8) , (0, 0, 0.1) ,
(0.1, 0.2, 0.1) /Sh+(0, 0, 0) , (0, 0, 0) , (0.9, 0.9, 0.1) /Sw
+(0.6, 0.6, 0.5) , (0.2, 0.1, 0.1) , (0.3, 0.3, 0.2) /H+(0.9, 0.8,
0.8) , (0.1, 0.1, 0) , (0.1, 0, 0) /MJ+(0.6, 0.6, 0.5) , (0.1, 0.2,
0.1) , (0.3, 0.4, 0.2) /C+(0.6, 0.5, 0.5) , (0.2, 0.2, 0.1) , (0.4,
0.3, 0.3) /LA+(0, 0, 0) , (0.1, 0.2, 0.1) , (0.8, 0.9, 0.8)
/CP+(0.5, 0.4, 0.3) , (0.4, 0.4, 0.3) , (0.4, 0.5, 0.3) /F+(0.4,
0.3, 0.3) , (0.3, 0.3, 0.2) , (0.5, 0.4, 0.5) /RNSCC= (0.1, 0.5,
0.7) , (0.1, 0.1, 0.2) , (0.9, 0.4, 0.3) /T+(0.9, 0.8, 0.8) , (0.1,
0, 0.1) , (0, 0.2, 0.1) /Sh+(0, 0, 0) , (0.2, 0.1, 0.1) , (0.9,
0.4, 0.3) /Sw +(0.6, 0.6, 0.5) , (0.2, 0.1, 0.1) , (0.3, 0.2, 0.2)
/H+(0.7, 0.6, 0.6) , (0.3, 0.1, 0.1) , (0.2, 0.3, 0.3) /MJ +(0.6,
0.6, 0.5) , (0.1, 0.2, 0.1) , (0.3, 0.4, 0.2) /C+(0.6, 0.5, 0.5) ,
(0.2, 0.2, 0.1) , (0.4, 0.3, 0.3) /LA+(0.5, 0.5, 0.4) , (0.1, 0.1,
0) , (0.4, 0.3, 0.3) /CP+(0.5, 0.4, 0.3) , (0.4, 0.4, 0.3) , (0.4,
0.5, 0.3) /F+(0.7, 0.7, 0.6) , (0.2, 0.2, 0.1) , (0.3, 0.3, 0.4)
/RNS13RajashiChatterjeeetal./Ann. FuzzyMath. Inform. x(201y),No.
x,xxxx.The disease of the patient is diagnosed using the weighted
similarity measure (Def-inition6.5.). Suppose,
forthesakeofdiagnosis,
thehighestpriorityisassignedtoheadacheandmuscleandjointacheandconsequentlysymptomssuchas,shivering,sweating,coughing,runningnoseandshivering,chestpain,fatigue,lossofappetiteandbodytemperaturehave
beenprioritized. Letthe respectiveweights assignedtoT, Sh, Sw, H,
MJ, C, LA, CP, LA, CP, F, RNSbe0.2, 0.7, 0.7, 0.9, 0.9, 0.6,
0.3,0.4,0.3and0.6.Thedecisionmakingprocess involves
calculatingtheweightedsimilaritymea-sures between the SVNMS Pfand
the respective SVNMS representing the
diseases.ThesetbearingthehighestmeasureofsimilaritywithrespecttoPfisthediseasethathasaectedtheperson.
Inordertoconrmtheobtainedresult,theprocessisrepeatedformorethanoneintegralvaluesofpi.e.
thesimilaritydegree.Thecalculationshavebeenrepresentedinatabularformasfollows:DiseaseSetsSimilarityDegree(p)
PatientData TB Inf CCp = 1 Pf0.69 0.89 0.87p = 2 Pf0.68 0.86 0.85p
= 3 Pf0.66 0.85 0.83Table 7.2. Tableshowingthe similaritymeasures
betweenthediseasesetsandPf.Thus,
fromtheabovendingsitisclearthatthepatienthasbeensueringfromInuenza.8.
ConclusionIn this paper a new hybridized concept, namely Single
Valued Neutrosophic Mul-tisethasbeenstudied.
Varioussettheoreticandalgebraicoperatorshavebeende-ned and their
properties have been discussed. The notions of distance and
similaritymeasureshavealsobeenincorporated.
Finallyanexamplecitingtheapplicabilityofsinglevaluedneutrosophicmultisetsinproblemspertainingtomedicaldiagnosishas
been stated. Being characterized by an indeterminacy membership
value, singlevalued neutrosophic sets provide a far more
generalized tool in handling
uncertaintyascomparedtofuzzysetsorintuitionisticfuzzysets.
Sincesinglevaluedneutro-sophicmultisetshaveresultedbymergingtogethertheconceptsof
multisetsandsinglevaluedneutrosophicsets,theformerareafurthergeneralizationofthelatterin
the sense that in this case multiple occurrances of an element with
varying degreesof
membershipvaluesaretakenintoconsiderationandthushavemoredegreesoffreedomcomparedtothelatter.
Moreover, thenotionsof
distanceandsimilaritymeasuresarestatedwithaviewtoaidinthewidespreadapplicabilityof
SVNMSin elds like medical diagnosis,data retrieval on the web or in
multicriteria decisionmakingproblems.14RajashiChatterjeeetal./Ann.
FuzzyMath. Inform. x(201y),No. x,xxxxAcknowledgments.
Theauthorsexpresstheirsincerethankstotheanonymousreferees for their
valuable and constructive suggestions which have improved the
pre-sentation.
TheauthorsarealsothankfultotheEditors-in-ChiefandtheManagingEditorsfortheirvaluableadvice.Theresearchof
therstauthorissupportedbyUniversityJRF(JuniorResearchFellowship).Theresearchof
thesecondauthor is supportedbyUGC(ERO) Minor ResearchProject.The
research of the third author is partially supported by the Special
Assistance Pro-gramme (SAP) of UGC, New Delhi, India [Grant No. F
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L.A.Zadeh,FuzzySets,InformationandControl8(3)(1965)338-353.Rajashi
Chatterjee([email protected])DepartmentofMathematics,Visva-Bharati,Santiniketan-731235,WestBengal,In-dia.P.Majumdar([email protected])Department
of Mathematics, M.U.C. Womens College, Burdwan-713104, West
Ben-gal,India.S.K.Samanta([email protected])DepartmentofMathematics,Visva-Bharati,Santiniketan-731235,WestBengal,In-dia.16