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Chaos enhanced differential evolution in the task of evolutionary control of discrete chaotic LOZI map

Šenkeřík, Roman

Abstract

In this paper, evolutionary technique Differential Evolution (DE) is used for the evolutionary tuning of controller parameters for the stabilization of selected discrete chaotic system, which is the two-dimensional Lozi map. The novelty of the approach is that the selected controlled discrete dissipative chaotic system is used within Chaos enhanced heuristic concept as the chaotic pseudo-random number generator to drive the mutation and crossover process in the DE. The idea was to utilize the hidden chaotic dynamics in pseudo-random sequences given by chaotic map to help Differential evolution algorithm in searching for the best controller settings for the same chaotic system. The optimizations were performed for three different required final behavior of the chaotic system, and two types of developed cost function. To confirm the robustness of presented approach, comparisons with canonical DE strategy and PSO algorithm have been performed.

Full text

THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER Chaos Enhanced Di e en ial E olu ion in he Task o E olu iona y Con ol o Disc e e Chao ic Lozi Map Roman SENKERIK1,2, I an ZELINKA1,3, Michal PLUHACEK2 1Modeling E olu iona y Algo i hms Simula ion and A i icial In elligence, Facul y o Elec ical and Elec onics Enginee ing, Ton Duc Thang Uni e si y, 19 Nguyen Huu Tho S ee , 700000 Ho Chi Minh Ci y, Vie nam 2Depa men o In o ma ics and A i icial In elligence, Facul y o Applied In o ma ics, Tomas Ba a Uni e si y in Zlin, T. G. Masa yka 5555, 760 01 Zlin, Czech Republic 3Depa men o Compu e Science, Facul y o Elec ical Enginee ing and Compu e Science, VSB–Technical Uni e si y o Os a a, 17. lis opadu 15, 708 33 Os a a, Czech Republic senk[email p o ec ed], i an.zelink[email p o ec ed], [email p o ec ed] DOI: 10.15598/aeee. 14i3.1166 Abs ac . In his pape , e olu iona y echnique Di - e en ial E olu ion (DE) is used o he e olu iona y uning o con olle pa ame e s o he s abiliza ion o selec ed disc e e chao ic sys em, which is he wo- dimensional Lozi map. The no el y o he app oach is ha he selec ed con olled disc e e dissipa i e chao ic sys em is used wi hin Chaos enhanced heu is ic con- cep as he chao ic pseudo- andom numbe gene a o o d i e he mu a ion and c osso e p ocess in he DE. The idea was o u ilize he hidden chao ic dynamics in pseudo- andom sequences gi en by chao ic map o help Di e en ial e olu ion algo i hm in sea ching o he bes con olle se ings o he same chao ic sys em. The op imiza ions we e pe o med o h ee di e en equi ed inal beha io o he chao ic sys em, and wo ypes o de eloped cos unc ion. To con i m he obus - ness o p esen ed app oach, compa isons wi h canonical DE s a egy and PSO algo i hm ha e been pe o med. Keywo ds Di e en ial e olu ion, de e minis ic chaos, chaos con ol, op imiza ion. 1. In oduc ion In many applica ions, one o he mos challenging asks is he con olling o highly nonlinea dynamical sys ems in o de o ei he elimina e o synch onize he chaos. The i s success ul app oach o con ol chao ic dynam- ics by means o a simple linea iza ion echnique was in oduced in he 1990s by O , G ebogy and Yo ke (i.e. OGY me hod) [1]. La e , apid de elopmen o me hods o s abilizing chao ic dynamics has a isen, and mo e ad anced mode n echniques ha e been ap- plied o chaos con ol and synch oniza ion including uncon en ional me hods om he so compu ing ield. The mos cu en in elligen me hods a e mos ly based on so compu ing, which is a discipline igh ly bound o compu e s, ep esen ing a se o me hods including special algo i hms, belonging o he a i i- cial in elligence pa adigm. The mos popula o hese me hods a e neu al ne wo ks, E olu iona y Algo i hms (EA’s) and uzzy logic. Cu en ly, EA’s a e known as a powe ul se o ools o almos any di icul and com- plex op imiza ion p oblem. The in e es abou he connec ion be ween e olu- iona y echniques and (no only) con ol o chao ic sys ems is apidly sp eading. The ini ial esea ch was conduc ed in [2], whe eas [3] and [4] was mo e con- ce ned wi h he uning o pa ame e s inside he exis - ing chaos con ol echnique based on he Py agas Ex- ended Delay Feedback Con ol (ETDAS), [5]. La e wo ks [6], [7], and [8] in oduce a no el app oach o gene a ing he en i e con ol law (con ol me hod) o he pu pose o s abiliza ion o any chao ic sys em. O he app oaches u ilizing he EA’s o he s abiliz- ing o chao ic dynamics ha e mos ly applied he Pa - icle Swa m Op imiza ion algo i hm (PSO), [9], and mul i-in e al g adien -me hod [10] o minimum en- opy con ol echnique [11]. EA’s ha e been also e- quen ly used in he ask o synch oniza ion o chaos [12], [13] and [14]. In [15] an EA o op imizing lo- c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 304 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER cal con ol o chaos based on a Lyapuno app oach is p esen ed. Ano he example o he connec ion be ween de e minis ic chaos and EA’s ep esen s he embedding o chao ic dynamics in o he EA’s. Recen esea ch has p o en ha chao ic app oach is able o bypass local op- ima s agna ion. A chao ic app oach uses any chao ic sys em in he place o a pseudo- andom numbe gen- e a o [16]. This causes he heu is ic o map unique egions since he chao ic map i e a es o new egions due o he basic p ope y o de e minis ic chaos, which is he densi y o pe iodic o bi . The ini ial concep o embedding chao ic dynamics in o EA’s is gi en in [17]. La e , he ini ial s udy [18] was ocused on he simple embedding o chao ic sys ems in he o m o Chaos Pseudo-Random Num- be Gene a o (CPRNG) o Di e en ial E olu ion (DE), [19], and Sel O ganizing Mig a ing Algo i hm (SOMA), [20], in he ask o op imal PID uning. Also, he PSO algo i hm wi h elemen s o chaos was in o- duced as he CPSO [21]. This ield o esea ch was la e ex ended wi h he success ul expe imen s wi h chaos d i en DE [22] in eal domain as well as in combina o- ial p oblems domain [23] and [24]. A he same ime, he chaos embedded PSO wi h in- e ia weigh s a egy was closely in es iga ed [25], ol- lowed by he in oduc ion chao ic i e ly algo i hm [26]. The o ganiza ion o his pape is as ollows: i s ly, used e olu iona y echnique, which is DE, is desc ibed, and ollowed by he desc ip ion o he ChaosDE concep . The ea e , he p oblem design and app op ia e co e- sponding cos unc ions a e in es iga ed and p oposed. Resul s and conclusion ollow a e wa d. 2. Mo i a ion This pape ex ends he esea ch o e olu iona y chaos con ol op imiza ion by means o ChaosDE algo i hm [27]. In his pape he DE/ and/1/bin s a egy d i en by di e en chao ic map (sys em) was u ilized o sol e he issue o e olu iona y op imiza ion o chaos con ol o he same chao ic sys em used as a CPRNG in he pa icula case s udy. Thus, he idea was o u ilize he hidden chao ic dynamics in pseudo- andom sequences gi en by chao ic map o help Di e en ial e olu ion al- go i hm in sea ching he bes con olle se ings o he e y same chao ic sys em. Since he posi i e con ibu- ion o he chao ic dynamics o he pe o mance o DE in he ask o e olu iona y chaos con ol op imiza ion was p o en in compa ison wi h o iginal canonical DE wi hin he ini ial s udy [28], his pape is no p ima - ily ocused on he pe o mance compa isons wi h he di e en heu is ic. This esea ch ex ends he ini ial wo k wi h he a o e- men ioned idea and wi h he se e al case s udies com- bining di e en equi ed s a es o he sys em (i.e. di - e en Uns able Pe iodic O bi s - UPOs) and di e en u ilized cos unc ions. 3. Used Heu is ic - Di e en ial E olu ion DE is a simple and powe ul popula ion-based op i- miza ion me hod ha wo ks ei he on eal-numbe - coded indi iduals o wi h small modi ica ions on dis- c e e ype indi iduals [19], [29] and [30]. DE is qui e o- bus , as , and e ec i e, wi h global op imiza ion abil- i y. This global op imiza ion abili y has been p o en in many in e disciplina y ypes o esea ch. I wo ks well e en wi h noisy and ime-dependen objec i e unc- ions. Recen ly hyb idized DE s a egies ha e been de eloped [31], [32] and also sel -adap i e DE a ian s [33], [34] and [35] ha e p o en o be powe ul heu is ics. Basic canonical p inciple is ollowing. Fo each indi idual ~xi,G in he cu en gene a ion G, DE gene a es a new ial indi idual ~ x0 i,G by adding he weigh ed di e ence be ween wo andomly selec ed indi iduals ~x 1,G and ~x 2,G o a andomly selec ed hi d indi idual ~x 3,G. The esul ing indi idual ~ x0 i,G is c ossed-o e wi h he o iginal indi idual ~xi,G. The i ness o he esul ing indi idual, e e ed o as a pe - u bed ec o ~ui,G+1, is hen compa ed wi h he i - ness o ~ui,G. I he i ness o ~ui,G+1 is g ea e han he i ness o ~xi,G, hen ~xi,G is eplaced wi h ~ui,G+1; o he wise, ~xi,G emains in he popula ion as ~xi,G+1. Please e e o Eq. (1) o no a ion o c osso e , and o [19] o he de ailed desc ip ion o used DERand1Bin s a egy and all o he DE s a egies: ~ui,G =~x 1,G +F(~x 2,G −~x 3,G).(1) 4. Concep o ChaosDE This sec ion con ains he desc ip ion o disc e e dissi- pa i e chao ic map, which can be used as he chao ic pseudo- andom gene a o s o DE as well as he main p inciple o he ChaosDE concep . In his esea ch, di- ec ou pu i e a ions o he chao ic map we e used o he gene a ion o pseudo andom numbe s. Two ypes o numbe s a e equi ed: eal numbe s in he p ocess o c osso e based on he use de ined CR alue and in ege alues used o selec ion o indi iduals. The gene al idea o ChaosDE and CPRNG is o e- place he de aul PRNG wi h he disc e e chao ic map. Since he disc e e chao ic map is a se o equa ions wi h a s a ic s a posi ion, a andom s a posi ion c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 305 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER o he map is c ea ed in each un o EA, in o de o ha e di e en s a posi ion o di e en expe imen s ( uns o EA’s). This andom posi ion is ini ialized wi h he de aul PRNG, as a one-o andomize . Thus, he concep o ChaosDE is u ilizing he amous and well-known “bu e ly e ec ” i.e. ex eme sensi i i y o chao ic sys em o he ini ial condi ions. As wo di e en ypes o numbe s a e equi ed in ChaosDE; eal and in ege s, he use o modulo ope - a o s is used o ob ain alues be ween he speci ied anges, as gi en in he ollowing Eq. (2) and Eq. (3): nd eal = mod (abs ( ndChaos),1.0) ,(2) ndin = mod (abs ( ndChaos),1.0)×Range+1,(3) whe e abs e e s o he absolu e po ion o he chao ic map gene a ed numbe ndChaos, and mod is he modulo ope a o . Range speci ies he alue (inclusi e), whe e he numbe is o be scaled. 5. Lozi Map This sec ion con ains he ma hema ical and g aphical desc ip ion o he selec ed disc e e dissipa i e sys em, which se es bo h as o CPRNG and also as he ex- ample o he sys em o be e olu iona y con olled. The Lozi map is a simple disc e e wo-dimensional chao ic map. The map equa ions a e gi en in Eq. (4). The pa ame e s used in his wo k a e a= 1.7and b= 0.5as sugges ed in [36]. Fo hese alues, he sys em exhibi s ypical chao ic beha io and wi h his pa ame e se ing i is used in he mos esea ch pape s and o he li e a u e sou ces [37]: Xn+1 = 1 −a|Xn|+b·Yn Yn+1 =Xn .(4) The x, y plo o he selec ed map is depic ed in Fig. 1. The chao ic beha io o he chao ic map, ep esen ed by he example o di ec ou pu i e a ions is depic ed in Fig. 2, whe eas he Fig. 3 shows he example o chao ic dynamics ans e ed in o he ange h0,−1i. Finally, he illus a i e his og am o he dis ibu ion o eal numbe s ans e ed in o he ange h0,−1igen- e a ed by means o chao ic Lozi map is shown in Fig. 4. 6. Cos Func ion Design The idea o he basic cos unc ion (CFSimple), which could be used p oblem- ee only o he s abiliza ion o p−1o bi , was o minimize he a ea c ea ed by he di - e ence be ween he equi ed s a e and he eal sys em -1.0 -0.5 0.0 0.5 1.0 -1.0 -0.5 0.0 0.5 1.0 x Fig. 1: x, y plo o he Lozi map. Fig. 2: I e a ions o he uncon olled Lozi map ( a iable x). Fig. 3: Example o he chao ic dynamics: ange h0,−1igene - a ed by means o he Lozi map. ou pu in he whole simula ion in e al −τiEq. (5). This CF design is e y con enien o he e olu iona y sea ching p ocess due o he ela i ely a o able CF su ace. The disad an age o he app oach is ha CF alue is in luenced by chao ic ansien beha io o he non-s abilized sys em. As a esul o his, he small change in con ol me hod se ing o ex emely sensi- i e chao ic sys em (gi en by he e y small change o CF alue), can be supp essed by he abo e-men ioned c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 306 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER 0.2 0.4 0.6 0.8 1.0 Value 100 200 300 400 Fig. 4: His og am o he dis ibu ion o eal numbe s ans- e ed in o he ange h0,−1igene a ed by he Lozi map (5000 samples). including o ini ial chao ic ansien : CFSimple = τi X =0 |T S −AS |,(5) whe e T S is a ge s a e and AS is ac ual s a e. Di e en ype o uni e sal cos unc ion is pu ely based on sea ching o he desi ed s abilized pe iodic o bi and he ea e calcula ion o he di e ence be- ween desi ed and ac ual pe iodic o bi in he sho ime in e al −τs(20 i e a ions) om he poin , whe e he i s minimal alue o di e ence be ween desi ed and ac ual sys em ou pu is ound (i.e. loa ing win- dow o minimiza ion, Fig. 5). Fig. 5: Floa ing window o he op imiza ion. Such a design o uni e sal CF should secu e he suc- cess ul s abiliza ion o ei he p−1o bi (s able s a e) o any highe pe iodic o bi anywise phase shi ed. Fu - he mo e, due o CF alues con e ging owa ds ze o, his CF also allows using decision ules and a oiding e y ime demanding simula ions. This ule s ops EA immedia ely, when he i s indi idual wi h good pa- ame e s uc u e is eached, since he alue o CF is lowe han he accep able one (CFacc). Based on he nume ous expe imen s, ypically CFacc = 0.001 a ime in e al τs= 20 i e a ions, hus he di e ence be- ween desi ed and ac ual ou pu has he alue o 0.0005 pe i e a ion – i.e. success ul s abiliza ion o he used con ol echnique. The CFUNI has he o m desc ibed in Eq. (6): CFUNI =pen1+ τ2 X =τ1 |T S −AS |,(6) whe e τ1is he i s min alue o di e ence be ween T S and AS,τ2is he end o op imiza ion in e al (τ1+τs), pen1= 0 i τi−τ2≥τsand pen1= 10 ·(τi−τ2)i τi−τ2< τs(i.e. la e s abiliza ion). 7. Expe imen Design This esea ch encompasses six case s udies. Th ee di - e en equi ed beha io o he chao ic sys em and wo di e en cos unc ions we e combined in he ollowing o m: •Case s udy 1: p−1UPO, Lozi map as CPRNG/Con olled sys em wi h CFSimple. •Case s udy 2: p−1UPO, Lozi map as CPRNG/Con olled sys em wi h CFUNI. •Case s udy 3: p−2UPO, Lozi map as CPRNG/Con olled sys em wi h CFSimple. •Case s udy 4: p−2UPO, Lozi map as CPRNG/Con olled sys em wi h CFUNI. •Case s udy 5: highe o de p−4UPO, Lozi map as CPRNG/Con olled sys em wi h CFSimple. •Case s udy 6: highe o de p−4UPO, Lozi map as CPRNG/Con olled sys em wi h CFUNI. This wo k is ocused on he u iliza ion o he chaos d i en DE o uning o pa ame e s o ETDAS con ol me hod o s abilize desi ed Uns able Pe iodic O bi s (UPO). In he desc ibed esea ch, desi ed UPO was p− 1(s able s a e). The o iginal con ol me hod, ETDAS, in he disc e e o m sui able o disc e e chao ic maps has he o m Eq. (7) and Eq. (8): Fn=K[(1 −R)Sn−m−xn],(7) sn=xn·R·Sn−m,(8) whe e Kand Ra e adjus able cons an s, Fis he pe u ba ion; Sis gi en by a delay equa ion u ilizing p e ious s a es o he sys em, mis he pe iod o m- pe iodic o bi o be s abilized. The pe u ba ion Fn in Eq. (8) may ha e a bi a ily la ge alue, which can cause di e ging o he sys em. The e o e, Fnshould all be ween −Fmax,Fmax. The anges o all e olu iona y es ima ed pa ame e s a e gi en in Tab. 1. c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 307 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER Tab. 1: Es ima ed pa ame e s. Pa ame e Min Max K-2 2 R0 0.99 Fmax 0 0.9 Tab. 2: DE e sions se ings. Pa ame e Value PopSize 25 FCanonicalDE 0.5 C Canonical DE 0.9 FChaosDE 0.5 C ChaosDE 0.6 Gene a ions 300 Max. CF E alua ions (CFE) 7500 Wi hin he esea ch, a o al numbe o 50 simula- ions o each case s udy and each DE e sion we e ca ied ou . The pa ame e se ings o bo h ChaosDE and Canonical DE we e gi en ollowing way (Tab. 2). Besides he pa ame e s de ining he size o popula ion and numbe o gene a ions, o he wo in e nal un- ing pa ame e s o DE, which a e mu a ion cons an F and c osso e pa ame e C , a e e y impo an in he DE pe o mance issue. Canonical DE u ilizes he well- p o en and ecommended se ings [38] Recen esea ch in he chaos and complex dynamics d i en heu is ics shows ha DE equi es lowe alues o a o emen ioned in e nal pa ame e s [30]. The e o e, simple uning wi h he inc emen al s ep o 0.1 has been conduc ed o ChaosDE (Tab. 3). Expe imen s we e pe o med in an en i onmen o Wol am Ma hema ica, PRNG ope a ions. The e o e, used he buil -in Ma hema ica so wa e pseudo- andom numbe gene a o . All expe imen s used di e en ini- ializa ion, i.e. di e en ini ial popula ion was gene - a ed in each un o Canonical/ChaosDE. Tab. 4: The alues o desi edUPOs. UPO Values o UPO o unpe u bed sys em p−1xF= 0.454545 p−2x1=−0.382166;x2= 0.700637 p−4x1=−0.691899;x2= 0.334059; x3= 0.086151;x4= 1.020573 8. Resul s All simula ions we e success ul and ga e new op imal se ings o ETDAS con ol me hod secu ing he as s abiliza ion o he chao ic sys em a equi ed beha - io s, which we e p−1UPO (s able s a e), p−2UPO (oscilla ion be ween wo alues) and inally p−4UPO. Pe o mances o bo h s udied DE s a egies a e com- pa ed wi h he ep esen a i e o swa m algo i hm, which is Pa icle Swa m Op imize (PSO). The canon- ical e sion wi h ine ia weigh s a egy [9] has been u ilized. The maximal cos unc ion e alua ion alue, popula ion size and he numbe o i e a ions we e se iden ically as o he bo h DE s a egies. The o ganiza ion o he esul s is ollowing. Table 5, Tab. 6, Tab. 8, Tab. 9, Tab. 11, and Tab. 12 a e ocused on he pe o mance compa isons be ween canonical DE, ChaosDE d i en by Lozi map; and swa m based PSO algo i hm. These ables con ain simple s a is i- cal o e iew o e olu iona y op imiza ion/simula ion esul s i.e. a e age, median maximum, minimum ( he bes solu ion), s d. de . alues o he pa icula cos unc ion and o all 50 uns o bo h compa ed heu is- ics. I alic numbe s ep esen he bes esul . Tab. 3: Resul s o uning o in e nal pa ame e s Fand C o ChaosDE om he in e al h0.1,0.9iand inc emen al s ep o 0.1 – A e age cos unc ion esul s o 30 uns o ChaosDE op imizing he highe nonlinea ask: Case s udy 2. C =0.1 C =0.2 C =0.3 C =0.4 C =0.5 F=0.1 4.39444 ·10−15 4.14344 ·10−15 4.16289 ·10−15 4.37956 ·10−15 4.14627 ·10−15 F=0.2 4.37891 ·10−15 4.09678 ·10−15 3.88405 ·10−15 3.95291 ·10−15 3.92013 ·10−15 F=0.3 4.35117 ·10−15 3.96566 ·10−15 3.84068 ·10−15 3.82903 ·10−15 3.90125 ·10−15 F=0.4 4.47881 ·10−15 3.98678 ·10−15 3.85901 ·10−15 3.81791 ·10−15 3.82793 ·10−15 F=0.5 4.43944 ·10−15 4.00844 ·10−15 3.85903 ·10−15 3.81515 ·10−15 3.78464 ·10−15 F=0.6 4.44328 ·10−15 4.01397 ·10−15 3.92736 ·10−15 3.82460 ·10−15 3.81850 ·10−15 F=0.7 4.43664 ·10−15 4.00505 ·10−15 3.87791 ·10−15 3.80962 ·10−15 3.82570 ·10−15 F=0.8 4.45275 ·10−15 4.04009 ·10−15 3.90736 ·10−15 3.83625 ·10−15 3.83625 ·10−15 F=0.9 4.44226 ·10−15 4.13174 ·10−15 3.91846 ·10−15 3.82625 ·10−15 3.83793 ·10−15 C =0.6 C =0.7 C =0.8 C =0.9 F=0.1 5.83432 ·10−73.52617 ·10−10 0.0000271935 0.172951 F=0.2 3.99240 ·10−15 4.15958 ·10−15 3.16606 ·10−12 0.0000531224 F=0.3 3.86901 ·10−15 0.0000501611 3.96350 ·10−15 4.16068 ·10−15 F=0.4 3.79960 ·10−15 3.82458 ·10−15 3.85238 ·10−15 3.90238 ·10−15 F=0.5 3.75962 ·10−15 3.77407 ·10−15 3.79903 ·10−15 3.87791 ·10−15 F=0.6 3.79684 ·10−15 3.79572 ·10−15 3.79625 ·10−15 3.85182 ·10−15 F=0.7 3.79680 ·10−15 3.76240 ·10−15 3.81350 ·10−15 3.88070 ·10−15 F=0.8 3.79125 ·10−15 3.76964 ·10−15 3.80127 ·10−15 3.86570 ·10−15 F=0.9 3.78905 ·10−15 3.79184 ·10−15 3.78738 ·10−15 3.85848 ·10−15 c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 308 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER Tab. 5: Compa ison o ChaosDE, canonical DE and PSO case s udy 1. S a is ical da a ChaosDE Canonical DE PSO CF Value CF Value CF Value Min 0.520639 0.520639 0.530679 Max 0.522148 0.527132 0.573742 A e age 0.520696 0.520769 0.548688 Median 0.520639 0.520639 0.549588 S d. De . 2.78·10−49.18·10−41.07·10−2 Tab. 6: Compa ison o ChaosDE, canonical DE and PSO case s udy 2. S a is ical da a ChaosDE Canonical DE PSO CF Value CF Value CF Value Min 3.53307 ·10−15 3.55511 ·10−15 4.41022 ·10−15 Max 4.05511 ·10−15 3.91062 ·10−15 5.21022 ·10−15 A e age 3.75362 ·10−15 3.7514 ·10−15 4.79336 ·10−15 Median 3.75511 ·10−15 3.75511 ·10−15 4.78267 ·10−15 S d. De . 9.96 ·10−17 7.42 ·10−17 2.02977 ·10−16 Tab. 7: Bes solu ions – Joined case s udies 1 and 2, p−1UPO. Pa ame e Case s udy 1, CNSimple, ChaosDE Case s udy 2, CNUNI, ChaosDE K−1.11259 −0.859989 Fmax 0.9 0.65695 R0.289232 0.065673 CF Value 0.520639 3.53307 ·10−15 Is ab. Value 21 9 A g. e o pe i e a ion 7.21 ·10−15 2.07 ·10−15 Tab. 8: Compa ison o ChaosDE, canonical DE and PSO case s udy 3. S a is ical da a ChaosDE Canonical DE PSO CF Value CF Value CF Value Min 7.04967 6.99829 7.29818 Max 7.54409 7.33379 8.05143 A e age 7.30428 7.2827 7.67487 Median 7.33379 7.33379 7.6944 S d. De . 7.77 ·10−29.29 ·10−20.216771 Tab. 9: Compa ison o ChaosDE, canonical DE and PSO case s udy 4. S a is ical da a ChaosDE Canonical DE PSO CF Value CF Value CF Value Min 1.62665 ·10−91.68548 ·10−91.81061 ·10−6 Max 1.28207 ·10−21.36095 ·10−20.136879 A e age 7.57338 ·10−46.40434 ·10−40.008665 Median 1.42814 ·10−41.35227 ·10−40.001515 S d. De . 1.86 ·10−31.96 ·10−30.023862 Tab. 10: Bes solu ions – Joined case s udies 3 and 4, p−2UPO. Pa ame e Case s udy 3, CNSimple, ChaosDE Case s udy 4, CNUNI, ChaosDE K0.574025 −0.614527 Fmax 0.430788 0.508694 R0.445453 0.528986 CF Value 6.99829 1.62665 ·10−9 Is ab. Value 22 18 A g. e o pe i e a ion 2.98 ·10−81.99 ·10−11 c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 309 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER Tab. 11: Compa ison o ChaosDE, canonical DE and PSO case s udy 5. S a is ical da a ChaosDE Canonical DE PSO CF Value CF Value CF Value Min 13.8025 13.7305 14.9151 Max 19.2155 51.9391 29.6333 A e age 15.4354 21.7940 14.5647 Median 14.2014 14.2548 22.4428 S d. De . 1.1312 5.4219 3.5719 Tab. 12: Compa ison o ChaosDE, canonical DE and PSO case s udy 6. S a is ical da a ChaosDE Canonical DE PSO CF Value CF Value CF Value Min 1.39076 ·10−31.45946 ·10−32.04937 ·10−3 Max 1.4131 ·10−21.28539 ·10−21.14558 A e age 2.79004 ·10−32.09308 ·10−30.15435 Median 1.60824 ·10−31.62911 ·10−30.11778 S d. De . 3.49 ·10−32.19 ·10−30.25369 Tab. 13: Bes solu ions – Joined case s udies 5 and 6, p−4UPO. Pa ame e Case s udy 5, CNSimple, ChaosDE Case s udy 6, CNUNI, ChaosDE K−0.869336 −0.935913 Fmax 0.255559 0.623172 CF Value 13.7305 1.39076 ·10−3 Is ab. Value 46 39 A g. e o pe i e a ion 2.66 ·10−41.39 ·10−6 Resul s gi en in Tab. 7, Tab. 10 and Tab. 13 ep e- sen he di ec compa ison o chaos s abiliza ion p op- e ies o he joined case s udies ela ed o he iden ical UPO o be con olled. Tables show he bes ounded indi idual solu ions o pa ame e s se up o ETDAS con ol me hod, co esponding inal CF alue. Also hese ables show he Is ab. alue ep esen ing he numbe o i e a ions equi ed o s abiliza ion on he desi ed UPO and u he he a e age e o be ween de- si ed ou pu alue and eal sys em ou pu om he las 20 i e a ions. G aphical simula ion ou pu s o he bes indi id- ual solu ions o pa icula case s udies a e depic ed in Fig. 6, Fig. 7, Fig. 10, Fig. 11, Fig. 14 and Fig. 15 Fig. 6: Simula ion o he bes indi idual solu ion – ChaosDE and Lozi map: Case s udy 1, CNSimple,p−1UPO. whe eas he Fig. 8, Fig. 9, Fig. 12, Fig. 13, Fig. 16 and Fig. 17 show he simula ion ou pu o all 50 uns o ChaosDE con i ming he obus ness o his app oach. Fo he illus a i e pu poses, all g aphical simula ions ou pu s a e depic ed only o he a iable xo he chao ic sys ems. The alues o desi ed UPOs o unpe u bed chao ic Lozi map based on he ma hema ical analysis o he sys ems a e gi en in Tab. 4. F om he esul s p esen ed in he Tab. 5, Tab. 6, Tab. 7, Tab. 8, Tab. 9, Tab. 10, Tab. 11, Tab. 12 and Tab. 13 i is clea ha he CFSimple is e y con e- nien o he e olu iona y p ocess, which means ha epea ed uns o EA a e p o iding iden ical op imal Fig. 7: Simula ion o he bes indi idual solu ion – ChaosDE and Lozi map: Case s udy 2, CNUNI,p−1UPO. c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 310 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER esul s (i.e. e y close o he possible global ex eme). This is g aphically con i med in he Fig. 8, Fig. 12 and Fig. 16, which show all 50 simula ions. All he uns a e me ged in o he one line. Fig. 8: All 50 uns o EA – ChaosDE and Lozi map: Case s udy 1, CNSimple,p−1UPO. Fig. 9: All 50 uns o EA – ChaosDE and Lozi map: Case s udy 2, CNUNI,p−1UPO. Fig. 10: Simula ion o he bes indi idual solu ion – Canonical DE and Lozi map: Case s udy 3, CNSimple,p−2 UPO. Fig. 11: Simula ion o he bes indi idual solu ion – ChaosDE and Lozi map: Case s udy 4, CNUNI,p−2UPO. Fig. 12: All 50 uns o EA– Canonical DE and Lozi map: Case s udy 3, CNSimple,p−2UPO. Fig. 13: All 50 uns o EA – ChaosDE and Lozi map, Case s udy 4, CNUNI,p−2UPO. c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 311 THEORETICAL COMPUTER SCIENCE VOLUME: 14 |NUMBER: 3 |2016 |SEPTEMBER Fig. 14: Simula ion o he bes indi idual solu ion – Canonical DE and Lozi map: Case s udy 5, CNSimple,p−4 UPO. Fig. 15: Simula ion o he bes indi idual solu ion – Canonical DE and Lozi map: Case s udy 5, CNSimple,p−4 UPO. On he o he hand he disad an age o including o ini ial chao ic ansien beha io o no s abilized sys- em in o he cos unc ion alue and esul ing e y iny change o con ol me hod se ing o he ex emely sen- si i e chao ic sys em is causing supp ession o s abiliza- ion speed and nume ical p ecision. Resul s ob ained in he cases u ilizing he CNUNI lend weigh o he a gumen ha he echnique o pu e sea ching o pe iodic o bi s is ad an ageous o as e and mo e p ecise s abiliza ion o he chao ic sys em. The g aphical compa isons o he pe o mance anal- ysis o ChaosDE, Canonical DE and PSO wi hin all 6 case s udies a e gi en in complex Fig. 18 and Fig. 19. The i s one ep esen s he ime e olu ion o he cos unc ion alue o he bes indi idual solu ion, which a e gi en in Tab. 10, Tab. 11 and Tab. 13. Mo eo e , hese solu ions we e also used o he g aphical sim- ula ions in Fig. 6, Fig. 7, Fig. 10, Fig. 11, Fig. 14 and Fig. 15. Figu e 19 shows he compa isons o ime e olu ion o a e age CF alues o all 50 uns o ChaosDE/Canonical DE/PSO, con i ming he obus - ness o bo h used DE s a egies wi hin many epea ed Fig. 16: All 50 uns o EA – Canonical DE and Lozi map: Case s udy 5 - CNSimple,p−4UPO. Fig. 17: All 50 uns o EA – ChaosDE and Lozi map: Case s udy 6, CNUNI,p−4UPO. uns. Mo e abou he indings is gi en in he conclusion sec ion o his pape . 9. Conclusion In his pape , e olu iona y algo i hm Di e en ial E o- lu ion was used o he e olu iona y uning o con- olle pa ame e s o he s abiliza ion o selec ed dis- c e e chao ic sys em, which was he wo-dimensional Lozi map. The o iginali y o he p esen ed app oach is ha he selec ed con olled disc e e dissipa i e chao ic sys em is used also wi hin chaos enhanced heu is ic concep as he chao ic pseudo- andom numbe gene a- o o d i e he mu a ion and c osso e p ocess in he Di e en ial E olu ion. The idea was o u ilize he hid- den chao ic dynamics in he pseudo- andom sequences gi en by chao ic map o help Di e en ial E olu ion al- go i hm in sea ching o he bes con olle se ings o he iden ical chao ic sys em. The indings o he wo di e en cos unc ion de- signs can be summa ized as ollows: c 2016 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 312