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The use of fuzzy connectives to design real-coded genetic algorithms

Herrera Triguero, Francisco,Lozano, M.,Verdegay, José Luis

Abstract

Genetic algorithms are adaptive methods that use principles inspired by natural population genetics to evolve solutions to search and optimization problems. Genetic algorithms process a population of search space solutions with three operations: selection, crossover and mutation. A great problem in the use of genetic algorithms is premature convergence; the search becomes trapped in a local optimum before the global optimum is found. Fuzzy logic techniques may be used for solving this problem. This paper presents one of them: the design of crossover operators for real-coded genetic algorithms using fuzzy connectives and its extension based on the use of parameterized fuzzy connectives as tools for tackling the premature convergence problem.

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Ma h w a e&So C om pu i ng 3( 19 94)23 9-25 1 TheU s eo F uzz yC onnec i es oD esign Real-CodedGene icA lgo i hm s 3 F.He e a,M.Lozanoa nd J.L.V e dega y Dep . o Com pu e Sci enceandA ici alIn e ll igence Uni e si y o G anada,18071-G anada,S pa in e-mail:he e a,loz ano, e de gay@ obinson.ug .es Ab s ac Gen e icalgo i hmsa eadap i e me hods ha usep incip lesi nspi edb y na u alpopu la iongene ics oe ol esol u ions osea c handop imiza i on p oble ms.Gene icalgo i hmsp o cessapopula iono sea c hspac esolu ions wi h h eeope a ions:sele c ion,c osso e andm u a io n. Ag ea p o blemin heuseo gene icalgo i hmsisp ema u econ e gence; h esea c hbecomes appedinal ocalop im umbe o e hegloba lop im um is ound.F uzzylogic ec hniquesma ybeused o sol in g hisp oblem.This pape p esen soneo hem: hedesign o c osso e ope a o s o eal-coded gene icalgo i hmsusing uz zyconnec i esandi sex ens ionbasedon he useo pa ame e ized uzzyconnec i esa s ools o ac kling hep ema u e con e gencep oblem. Keyw o ds: Gene icAlgo i hms,RealC oding,F uzzyConne c i es. 1In oduc i on G ene i cal go i hm s( GAs)a esea c halgo i hms ha useope a io ns oundi n na u algen e ics og ui de he ek h oughase a ch space.G Asa e heo e ical ly a ndem pi ical ly p o en op o i de obus sea c hi nco m plexs paces,g i i nga al id app oa ch o p o blem s equi i ng ecien and e ec i esea c h([6] ). A GA s a s wi hapopula i on o ando mly ge ne a e d sol u i ons, c h o mosom es, and ad ance o wa ds be e so lu io ns b yapply ing g e ne ic op e a o s m odel ed o n he g e ne i c p o ce sse s o cc u ing i n na u e. In hes e al go i hm swemain ai n a p opula ion o sol u ions o a gi e n p oblem; his p opul a io n unde go es e olu i on in a o m o na u al s elec i on. In eac h ge ne a ion, ela i el y go o d sol u i ons ep o duc e o gi e o sp ing ha eplace he ela i el ybadso lu ions whic hdi e. An e al ua io no  nes s unc i on pla ys he ol eo heen i o nmen odi s i nguish b e wee n good and badsolu ions. 3 This esea chhasbeen suppo ed by DGICY T PB92- 0933. 239 240 F.He e a,M .L oz ano& J. L. V e dega y Al h o ugh he ea em a n ypossi ble a i an so hebasi cGA, he undam en al un de lyi ngm echa nismope a es on apo pul a i ono c h o mosome s( ep esen i ngpo s- si blesol u ions o hep oblem) andco nsi s so he o llo wing op e a io nswhic ha e appli eddu ingea chg ene a i on : 1.e alua ion o in di idua l ness, 2. o m a iono ag enepoo lb yc hoo si ngi ndi i dualsi np opo ion o hei ela i e  ness, 3. ec om bi na io nb ym eanso heg ene i cope a o c o sso e andm u a ion. Thep ocessisi e a e du n il hesys emceases oim p o eo ag i engene a ion T is ea ched. Fi xe d-l eng handbi na yencodeds ings o ep esen a ion so lu io nha edom - ina edG A esea c h,since he e exis heo e ical esul s ha sho w hem obe he m os a pp op i a e,a nd hey a eam ena bl e osim ple im plem en a io n.Bu heGA's goodp ope iesdono s em om heuseo bi s i ngs( [ 1] ).F o his eason, hepa hha sbeenlai n ow a ds heuseo al phabe swi h ahi ghe ca dinal , ol- lo w edb y hede el opme n o newgene icope a o s(c osso e andm u a ion)on hesealpha be s.Nonbina yencodingsi ncl ude ealnum be ep esen a i ons,whi ch w ouldseempa i cul a lyna u alwhenw ea e a ckl ingop i m iza i onp oble m so pa am e e swi h a ia blesi ncon i n uousdo mai ns.Thenac h o m osom ei sa ec o o oa ingpoi n n um be swhosesi zei sk ep hes am eas heleng ho he ec o whic hi s hesol u ion o hep obl em .G Aswi h his ypeo encodi ngwil lbecall ed eal -codedGAs(R CGAs). Theuseo ealpa am e e sm a k esi possi bl e ou se la gedom a ins(e enunknown dom ai ns ) o he a ia bles,whi c hi sd icul oac hie ei nbi na yim plem en a ions, whe e inc easing hedo m ai nw oul dm ea ns ac icingp eci si on,assumi ng axed leng h o hec h om osom es.Ano he a d an ag ewhenusi ng ealpa a me e sis hei capa ci y oe xplo i heg aduali yo he unc ionswi hcon i n uous a iabl es(whe e heco nc ep o g adual i y e e s o h e ac ha sl igh c hangesi n he a i ables co e spond osl igh c hangesi n he unc i on).Las l y , h ey al lo w he oo ls ha handlen on- i i al es ic ions ob ed esi gnedm o eeasi ly ,a nd he ep esen a ion o heso lu io nsi s e yc lo se o hena u al o m ul a io no m an yp obl em s. The m u a io no pe a o a bi a i ly al e s one o m o e c o mp onen s (c a lled ge nes) o asel ec ed s uc u e s o as o i nc e a se he s uc u al a i abil i y o he p opula i on, e. g., i explo es he se a c hspac e. Unde bi na y c od i ng, gi enag enewi h al ue 0 ", i is e pl ace d b y 1", and i ce e sa. Unde e a l co ding di e e n e sions o hi s op e a o w e e p ese n ed ([ 9] ). Eac h gene o e ac hc h om osom ein he p opul a ion un de go es a andom chang eacco di ng o a p obabil i y dene d by he m u a ion a e, he m u a ion p oba bi li y , p m . The c osso e o p e a o e xpl oi s he a ai la ble i n o m a ion om he p opul a ion ab ou he se a chspace. I combines he ea u e s o wopa en s uc u es o o m wosimila o sp ing. The classical c osso e op e a o unde bina y co ding builds TheUseo F uzzyC onne c i es o Desi gn. .. 2 41 an osp i ngb yl inki ng oge he w ogenesegm en s,eac ho ne be longi ng oadi e en pa e n .Thi sope a o i sappl iedw i hap obabi li yo pe o ma nce, hec osso e p obabi li y , p c , ha de e m i nes hen um be o c h om o som esin hepopula ion o be c ossed.[ 7,9 ] epo c osso e o pe a o m odelsunde b ina yand ealcodi ng . Thec osso e op e a o pla ysacen a l ole in h eGA' spe o m ance.I could beconside ed o be o neo healg o i hm 's deningc ha ac e is ics,andi i so ne o hecom po ne n s obea inm ind o im p o i ng heG A'sbeha io u ([ 12] ). The m u a ion op e a o isacom plem en o hec o sso e o pe a o .I isneed ed oa oid helo sso u se ulin o m a io np oduce db y hec osso e . Ani m po an p o blemin heu seo G Asis p ema u ec on e genc e ; hesea ch becom es appedi naloc al op i m umbe o e hegl obalo p im um i s ound.Thisi s p oducedb y hel ac ko di e si y in hepopul a ionandadi sp opo io na e exploi a- ion / explo a ion ela i onship;anadequa eba lancebe w ee nab oa dsea c handa sucien e nem en isno es a bl ished . F uzzy logi c ec hniquesm a ybeused os ol e hesep o blem s.Ana em p con- sis s o heu seo uzzyl ogi cbased sys em s o hedy nam i ccon ol pa am e e s o R CGA( p m , p c ,popula i onsize,e c)insuc haw a y h a heco ec exploi a- i on/explo a i on el a ionsh i pandsui abl edi e si yl e elsbecam ees abli shed([8 , 1 1]).Ano he o neuses uzzy co nnec i es odesig nc osso e o pe a o s([8] ). In hispape w ep esen c osso e ope a o s o R CGAsba sedo n heus eo uzzyco nnec i es,and hei e x ensi onbasedo n heuseo pa am e e i zed uzzy connec i es o designi ngdynam i cc osso e ope a o swi h hem ai nobj ec i eo in oducingpopula i ondi e si yi n heGAsea c h. 2 D esi gno C osso e O pe a o s o R CGAus- i ngF uzz yConne c i es Ash as a l ea dybeenpoi n edo u ,a ch om o som eisa ec o o e al nu m be s,and i s p ec i si onwi llbem a k edby h a o hecom pu e unde whi ch h ea l go i hmi s ca iedou .Thesi ze o hec h om osom ei sk ep hes am ea s hel eng ho he ec o ha is heso lu io n o he p oblem ;in hisw a y ,e ac hg ene ep esen sa a i abl e o hep oblem .The a lueso hec h om o som egenesa e o ced o em ai nin he i n e al e s abli s hed b y he a i able ha he c h om oso me e p e sen s , so he gene i c op e a o s m us p ese e his e qui em en . In[3]i w as p oi n ed ou ha he c osso e op e a o i sak ey poi n o sol ing he p em a u e con e genc e p oblem .Th us , s ol u ions o hi sp ob lem m aybe ound b y desi gni ng new al e na i es o hi sope a o . He e, he de el opm en o suc h c oss o e op e a o s is a em p e d. W e p e sen c osso e op e a o s o R CG A base d o n he use o uzz y connec i es: - no m s , -c o no m s, a e age unc ions and gene al ize d com p ens a ion op e a o s ([14 ,1 5]) whic h induce di  e e n di e si y le els in he p opula ion , and he e o e he p ema u e c on e genc e p oblem maybe con olled. Le usassume ha he ch omos omes C 1 =( c 1 1 ;c 1 2 ;:::; c 1 n )and C 2 =( c 2 1 ;c 2 2 ;:::; c 2 n ) 242 F.He e a,M .L oz ano& J. L. V e dega y a es elec ed oapply hec osso e ope a o o hem ,a nd w og en es c 1 i and c 2 i o be c ossedo e , c 1 i ;c 2 i 2 [ m i ;M i ], bei ng x i =m in( c 1 i ;c 2 i )a nd y i =m ax( c 1 i ;c 2 i ). I se em s easo nable oim agine he po ssibi li yo ob ai ningg oodd escenden sou si de h is in e al.Insho , hei n e alo ac io no heg en e i ,[ m i ;M i ], ma ybedi ided in o h ee egio ns[ m i ;x i ],[ x i ;y i ] ,a nd[ y i ;M i ],whe egooddescende n sm ay be ob ained;e enconside inga egi on[ x 0 i ;y 0 i ]wi h x 0 i  x i and y 0 i  y i w ouldseem easonabl e.G a phi ca ll y Fi gu e1 :Ac io nin e al o ag ene W esh al lno wg oon opu o w a dase o c osso e ope a o s ha al lo w desce nden s obeob ai nedin hep e i ousin e al s.Ino de o do ha ,w euse ou unc ions F , S , M a nd L dened om[ a;b ] 2 [ a;b ]i n[ a; b ] , a;b 2< ,whi ch ull l: (P1 ) 8 x;y 2 [ a; b ] F ( x;y )  m in( x;y ), (P2 ) 8 x;y 2 [ a ;b ] S ( x ;y )  m ax( x ;y ), (P3 ) 8 x; y 2 [ a ;b ]m in( x;y )  M ( x;y )  ma x( x;y ), (P4 ) 8 x;y 2 [ a ;b ] F ( x;y )  L ( x;y )  S ( x ;y ), (P5 ) F , S , M ,and L a e mono onenon-dec easing. Le usassum e ha Q 2 F;S;M;L g ,and C 1 =( c 1 1 :: :c 1 n )a nd C 2 =( c 2 1 :::c 2 n ) a e wo ch om osom es ha ha e b ee n s elec ed o apply he c osso e o p e a o o hem .W em ay gene a e he c h om osom e H =( h 1 :::h n )as H = Q ( C 1 ;C 2 ) ;h i = Q ( c 1 i ;c 2 i ) ; i =1 ;: :: ;n: W i h he -no m o p e a o s , -cono m s, a e a ging unc io ns and gene al ize d co mp e nsa io nope a o s used as uz zy c onnec i es , w e shall a s so cia e F wi h a - no m , S wi h a -cono m , M wi h ana e a ging o p e a o and L wi h a ge ne al- ize d comp ens a ion op e a o . Fi s , weneedase o linea ans o ma ions o be able o apply he se op e a o s unde he gen e deni ionin e als. TheUseo F uzzyC onne c i es o Desi gn. .. 2 43 Le O beano pe a o belonging o hese o m edb y he -no m s, -co no m s, a e a ging unc io nsandgene ali zedco m pensa io no pe a o s. F o eac hpo si ion i 2 1 ;: :: n g , he oll o wi ng op e a i onswil lbeca i edou : 1.T ans o m c 1 i and c 2 i in o he alues s 1 i ;s 2 i 2 [0 ; 1]s uc h ha s k i = c k i 0 m i M i 0 m i ;k =1 ; 2 : Usin g hi ss ep,w e ans o m he alueso hegenesso ha heo pe a o m a ybea ppl ied o hem . 2.Appl y heope a o O ( s 1 i ;s 2 i )andca lcula e he alu e h i : h i = m i +( M i 0 m i ) 1 O ( s 1 i ;s 2 i ) ; so ha hegene h i i si n el a ion oi s o ig inalli m i s, h i 2 [ m i ;M i ] . 3. h i wi llbe he alue o heg enea posi i on i o hec h o m osom e esul ing om hec o sso e o hec h o m osom es C 1 and C 2 . Com plyi ngwi hase o uzzyconnec i es,( T j ;G j ;P j ; ^ C j ), j =1 ;:: :;k ,ase o unc io ns F j , S j , M j and L j j =1 ;:: :;k isbuil a sw edesc i bebelo w: F j ( c 1 i ;c 2 i )= m i +( M i 0 m i ) 1 T j ( s 1 i ;s 2 i ) S j ( c 1 i ;c 2 i )= m i +( M i 0 m i ) 1 G j ( s 1 i ;s 2 i ) M j ( c 1 i ;c 2 i )= m i +( M i 0 m i ) 1 P j ( s 1 i ;s 2 i ) L j ( c 1 i ;c 2 i )= m i +( M i 0 m i ) 1 ^ C j ( s 1 i ;s 2 i ) Thesec oss o e op e a o sha edi e e n ea u es: he F -and S -c os so e s show explo a i on, he M -c osso e ope a o ssho wexpl oi a i onand he L -c osso e sho w elaxed exploi a io n. 3Exa m pl e W eha e ca i e d ou die en ex pe im en s h a help o com pa e hebeha iou o ab ina y c o ded GA, and som eR CG As wi h c os so e op e a o s h a ha ebeen p op ose d i n o he publi ca ions, wi h a s e o alg o i hm s bas ed on he c oss o e op e a o s p op ose d, which us e he uzzy connec i es ( T j ;G j ;P j ; ^ C j ), j =1 ;:::; 5 showed inTable1. 244 F.He e a,M .L oz ano& J. L. V e dega y -no m -cono mA e agingO pe a o LogicalP o duc LogicalS um T 1 ( x;y )=min( x;y ) G 1 ( x;y )=max( x;y ) P 1 ( x ;y )=(1 0 p ) x + py Hamac he P o duc Hamac he S um ( x )= 1 0 x x T 2 ( x;y )= xy x + y 0 xy G 2 ( x;y )= x + y 0 2 xy 1 0 xy P 2 ( x;y )= 1 y 0 yp 0 xy + xp xy +1 Algeb aicP oduc Algeb aicSum ( x )= 0 log x T 3 ( x ;y )= xyG 3 ( x ;y )= x + y 0 xyP 3 ( x;y )= x 1 0 p y p Eins einP oduc Eins einSu m ( x )=log 2 0 x x T 4 ( x;y )= xy 1+(1 0 x )(1 0 y ) G 4 ( x;y )= x + y 1+ xy P 4 ( x;y )= 2 1+( 2 0 x x ) p ( 2 0 y y ) 1 0 p BoundedP oduc BoundedSum ( x )=1 0 x T 5 ( x;y )= 0 _ ( x + y 0 1) G 5 ( x;y )=1 ^ ( x + y ) P 5 ( x ;y )= (1 0 p ) x + py T a ble1: Se o Op e a o s Eac h -cono mi sdual o he -no msho wn oi sl e . Thea e a ging unc ion iscal cula ed om he o m ulao hequasi-a i hme i ca e ages,usingas he unc i on hea ddi i e gene a o unc io no he -no mp la cedin hesa m eline, excep o he s one wh i c h,no bei ngA c him edean,d oesno ha eag ene a o unc i on,andw eshall us e ( x )= x .Thi s unc io ni ss ho wni n heuppe pa o hecel lswhe e hesea e agi ngope a o sa especi ed.F o ea ch am i lyo o pe a o s inT abl e1 ,agene al izedcom pensa ionope a o ^ C j wil lbeconside ed,denedas ol lo ws: ^ C j = P j ( T j ;G j ) Fo he am i lyo Lo gicalope a o s,w eshal lconside ^ C 1 = T 1 0 p 1 :S p 1 . TheGA am il iesa edi e en i a edacco di ng oho w heyca y ou he ol lo wing w os eps: 1.Gene a i on o osp ingusi ng hedie en c osso e ope a o s. 2.Sel ec iono osp i ng esu l ing om hec osso e whic hwil l o mpa o he po pula i on. Ap opo sali s he o llo wing :F o ea ch pai o c h om oso m es om a o al o 1 2 1 p c 1 N ( p c c osso e p obabi li y , N po pul a ionsize) , ou osp inga eg ene a ed, he es ul o applyi ng sp e cic u nc io ns F , S , M ,a nd L o hem .The wom os p o misi n g osp i ng o he ou epla ce hei pa en s in he p opula i on. Thi ss el e c ion s a egy in oduce sahi gh explo i a i on l e el wi h a n unde l ying expl o a ion c ause d b y he use o he die en Q -c oss o e o p e a o s . Nex , he esul s o nR ose n b o c k's Gene al ize d un c io n([ 4]) a e sho wn. The anal y i ca l and g aphi ca l o m ul a io n oge he wi h he elem en h a ep es en s he glo bal o p i mum(m inim um ) a e: ( ~x )= n 0 1 X i =1 (100 1 ( x i +1 0 x 2 i ) 2 +( x i 0 1) 2 ) TheUseo F uzzyC onne c i es o Desi gn. .. 2 45 0 5 : 12  x i  5 : 12 min( )= (1 ;:::; 1)=0 Fig u e2: whe e n =5. Ase o nineR CGAbasedo nc osso e ope a o sp es en edi n heli e a u e w e econside ed o he expe i m en s(R GA1-R GA9 ). Belo w he ei sa a bleindica - i ng he y peo c osso e a ndm u a io nusedb yeac ho hem , og e he wi h hei na m es. Algo i hmsMu a ionC os so e R GA 1 RandomSimpl e[13,17] R GA 2 Non- Uni o mSimple[13,17] R GA 3 RandomUni o mA i hme i cal[13] a =0 : 35 R GA 4 Non- Uni o mUni o mA i hme ical [13] a =0 : 35 R GA5-  Non- Uni o mBLX-  [5] (  =0 ;: 15 ;: 3 ;: 5) R GA 6 Non- Uni o mDisc e e [16] R GA 7 Non- Uni o mLinea [17] R GA 8 Non- Uni o m Ex endedI n e medi a e[16] R GA 9 Non- Uni o mEx endedLine[16] Tabl e2 : Real Co ded Gen e i cA lgo i hms By BGA w edeno eabi na y co ded GA wi h 30 genes pe a i able,m ul ipl e c oss o e wi h wopoi n s and p o po i onal se l ec i on p obabi li y. By NRG A 1 ; ::: ; N RGA 5w edeno e a a mil yo G A based on he uzzy conne c- i e s c oss o e and he gene a i on a nd sel ec i on o os p ing p op osals, using he amilie s o uz zy conne c i es: Log ical, Ham am che , Al ge b aic , Eins e i n and Bound, es pec i el y.Inal l case s w euse he s o cha s i c uni e sa lsam pl ing ([ 2]) se l ec ion p o ce du e and he e li is model. Weca ied ou ou exp e imen s u sing h e ol- lowing pa ame e s: h e p opula ion size is 61 indi iduals, he c osso e p obabili y 246 F.He e a,M .L oz ano& J. L. V e dega y p c =0 : 6,and hep obabi li yo c h om osom eupda e p u = p m 1 5=0 : 6,and hepa- a me e b usedb y henon-un i o mm u a i onis5.W eex ecu ed al l heal go i hm s3 i mes,ea chonewi h10 0,500a nd 5000gene a ions,a ndp es en hea e age al ue o hemi nT a bl e3. Al go i hms10 050050 00 BGA 1.1262e+013.6069e+ 001.9045e+00 R GA1 3.0446e+012.0070e +0 16.0669e+00 R GA2 6.9230e+002.1448e+ 004.7343e-01 R GA3 4.1941e+00 8.6031e+ 00 6.3745e+00 RGA4 3.7915e+002.9624e+ 008.9244e-01 R GA5-0.0 4.5504e+002.3454e+ 009.1602e-01 R GA5-0.15 3.215 7e+002.9556e+ 007.092 9e-01 R GA5-0.3 3.7477e+001.5844e+ 004.8854e-01 R GA5-0.5 8.2653e+002.1099e+ 001.7329e+00 R GA6 5.5393 e+002.8379 e+ 003.5106 e-01 R GA7 4.7115e+001.8487e+ 005.1499e-01 R GA8 4.6861e+003.5337e+ 005.3325e-01 R GA9 4.2196e+002.9374e+ 003.8014e-02 NR GA1 4.1431e+001.9687e+ 004.9364e-03 NR GA2 1.2378e+017. 38 68e-014.0848e-02 NR GA3 1.003 1e+013.5037e+ 001.0099e+00 NR GA4 1.2425e+014.3985e + 001.8347e+00 NR GA5 6.0121e+002.6930e+ 001.2150e+00 T a ble3: Resul s Thebes beha i ou co espo nds o heLog icalc osso e o pe a o .Thi sop- e a o oge he wi h heosp i ngsel ec i onm ec hanismoe asui a bleexplo i a- i on/explo a i onbal ance, al houghw em us poi n ou ha hi sm ec hani smi sm o e im eexpensi ebecauseneed mo e e a lua io ns.O he osp i ng sel ec ionm ec ha- nism sa ep oposedin[ 10] . 4 D esi gno Dynam i cC oss o e Op e a o sUsi ng Pa a me e i ze dF uzz yC on ne c i es A n idea o a oiding he p e m a u e c on e genc e consis s in al lo wi ng he e xplo a ion in he b e gi nning o he sea ch p o c es s and he e xpl oi a i on a he end o i . Wi h he explo a i on he di e si ybeca mes g ea e , i nc easing he p o babil i yo nding z ones whic ha e clo sed o op i mal s o lu io ns . Then, supp os i ng ha he p o pula- ion ha ei n o m a i on ab ou hese zones, he co n e genc e o wa ds he op i mumi s p o duce d h ough e xpl oi a i on. Am u a i on op e a o o R CG Acal le d non-uni o m m u a io n ([1 3]) is base d on he a o em en ioned p i nc i ple.T h e p o po i on in whic ha ea lgene is m u a e d de c ease s as he GA's e xec u ion ad ance. Thu s, he changes p o duc ed on he ge nes a e smalle in he las ge ne a ions p o duc ing a local uning. TheUseo F uzzyC onne c i es o Desi gn. .. 2 47 We ma yex end heuseo hec o ss o e o pe a o sp esen e di no de o oll o w hea o em en i onedi deas. Die en uzzyconnec i esc ould be useddu ing he GA's un.Fi s l y ,w eshall us e uz zyconnec i es ha p od uceh ighdi e si yle els, andl a e o he onesp oducingasu  ci en di e si yle el oa llo w heco n e g ence obe ea ched. W ep esen ase o d ynam ic c osso e ope a o sb ased on heuseo pa am e e - i zed -no m s, -co no m sa nda e ag ing unc i ons( [14, 15 ]).In he s s ag es, we shal luse -no m sand - co no m sdis an om hemi nimu m -no ma ndm a xim um -cono m espec i ely ,sohi ghdi e si yisi nduced.La e , - no m scl ose o he m ini m umand -cono m sclo se o hem a xim uma e conside ed.Theco n e g ence i scausedand hego od beha io u o helog ical uzz yconnec i eswil lbek ep . As w assho wninT able3, hes eope a o sa eingene al he m os p o  able. T odo his,w ep op osease o c o sso e ope a o sbasedon he unc io ns am ilie s: F p g p =1 ;:::;G , S p g p =1 ;:::; G ,and M p g p =1 ;: ::;G , G 2 N de ned om[ a;b ] 2 [ a;b ]in [ a;b ] , a;b 2< ,whic h ul ll hec o espondingP1 -P5p op e ies and: (P6) 8 x;y 2 [ a;b ] ; l im p ! G F p ( x; y )  = m in( x;y ) (P7) 8 x;y 2 [ a;b ] ; l im p ! G S p ( x;y )  = m ax( x ;y ) (P8) 8 x;y 2 [ a;b ] ; m i n( x; y )  M p ( x ;y )  x + y 2 o x + y 2  M p ( x;y )  m ax( x ;y ) and 8 x;y 2 [ a; b ] ; l im p ! G M p ( x ;y )  = x + y 2 Le us conside aGAwi ham axim um num be o gene a io ns  a nd C 1 = ( c 1 1 ;:: :c 1 n )and C 2 =( c 2 1 ;:::c 2 n ) w oc h om o som es ha w e es el ec e din hegene - a i on oa ppl y hec osso e o pe a o o hem .I Q p 2 F p ;S p ;M p g p =1 ;:::;  w em a yg ene a e hech om osome H =( h 1 ;:: :;h n )a s H = Q ( C 1 ;C 2 ) ; h i = Q ( c 1 i ;c 2 i ) ; i =1 ;: ::;n: W esha ll buil d unc i ons a mil ies wi h he (P6) and (P7) p op e i e s using he pa a me e ize d -no m sa nd - co no ms desc ib ed in T able 4. Ta ble 5 sho ws he p ope i e s o he pa am e e i zed -no m si n hi s a ble. The p op e ies o he pa- ame e iz ed -cono ms a e analogous. Wemus p oin ou ha T 6 is he d as ic -no m ( he smalles -no m).