Chapter 17. Hybrid Intelligent Decision Support Systems and Applications for Risk Analysis
N.Kasabov,L.Erzegovesi,M.Fedrizzi,A.Beber,andD.Deng
Dept.ofInformationScience,Univ.ofOtago,Dunedin,NewZealand.E-mail:nkasabov,ddeng@infoscience.otago.ac.nz
Dept.ofInformaticsandFacultyofEconomics,Univ.ofTrento,Italy
Abstract.Decisionmakinginacomplex,dynamicallychangingenvironmentisadifficulttaskthatrequiresnewtechniquesofcomputationalintelligenceforbuild-ingadaptive,hybridintelligentdecisionsupportsystems(HIDSS).Here,anewap-proachisproposedbasedonevolvingagentsinadynamicenvironment.Neuralnetworkandrule-basedagentsareevolvedfromincomingdataandexpertknowl-edgeifadecisionmakingprocessrequiresthis.Theagentsareevolvedfrommeth-odsincludedinarepositoryforintelligentconnectionistbasedinformationsystemsRICBIS(http://divcom.otago.ac.nz/infosci/kel/CBIIS.html)withtheuseoffinancialmarketdatacollectedinanon-linemode,andwiththeuseofmacroeconomicdatapublishedmonthlyintheEuropeanCentralBankBulletin.RICBISincludesdifferenttypesofneuralnetworks,includingMLP,SOM,fuzzyneuralnetworks(FuNN),evolvingfuzzyneuralnetworks(EFuNN),evolvingSOM,rule-basedsys-tems,datapre-processingtechniques,standardstatisticalandfinancialtechniques.AcasestudyprojectonriskanalysisoftheEuropeanMonetaryUnion(EMU)isconsideredandaframeworkofasystemEMU-HIDSSispresented,whichdealswithdifferentlevelsofinformationandusers,e.g.thewholeworld,Europe,clustersofnations,asinglenation,companies/banks.Itcombinesmodulesforfinaldecisionmaking,globalandnationaleconomicdevelopment,exchangeratetrendpredic-tion,stockindextrendprediction,etc.Someexperimentalresultsonrealdataarepresented.
Keywords.Intelligentdecisionsupportsystems,riskanalysis,connectionist-basedinforma-tionsystems.
1Introduction
Complexdecisionmakingproblemsveryoftenrequireconsideringenormousamountofinformationdistributedamongmanyvariables.Thedecisionsupportsys-tems(DSS)builttosolvetheseproblemsshouldhaveadvancedfeaturessuchas[19]:
Goodexplanationfacilities,preferablypresentingthedecisionrulesused;Dealingwithvague,fuzzyinformation,aswellaswithcrispinformation;
Dealingwithcontradictoryknowledge,e.g.,twoexpertspredictdifferenttrendsinthestockmarket;
Dealingwithlargedatabaseswithalotofredundantinformation,orcopingwithlackofdata.
Havinghierarchicalorganisation,asdecisionmakingisusuallynotasingle-levelprocess,butinvolvesdifferentlevelsofprocessing,comparingdifferentpossiblesolutions,usingalternatives,sometimesinarecurrentway.
Techniquesofcomputationalintelligence,suchasartificialneuralnetworks,fuzzylogicsystems,geneticalgorithms,advancedstatisticalmethods,hybridsystems,alongwithtraditionalstatisticalandfinancialanalysismethods,havebeenwidelyappliedondifferentproblemsfromfinanceandeconomics.Heresomeofthemarereferencesandexplained.
1.1SpecialisedandAdvancedStatisticalandEconometric
Models
In[45]amodelforriskanalysisoncrashesofcurrenciesisintroduced.Itconsid-ersacrashsituationwhenacurrencyhasbeendevaluatedmorethan10%withinamonthwhencomparedtotheUSdollar.Fourparametersareusedtoevaluatethelikelihoodofacrash(avalueof0or1)inthefollowingmonth:measureofcurrencyovervaluation;expecteddomesticoutputgrowth;ratiooffederalreservesversusex-ternaldebt;measuresofinternationalfinancialcontagion.Thelatterismeasuredinriskappetite(achangeininvestorspreferencesbeforecrashesoccur),andclus-ters(whethercrashesofcurrenciesfromthesameblockofcountrieshaverecentlyoccurred).Othermodelsarepresentedin[6].
Themethodsinthisgrouprequireareliableknowledgeontheunderlyingrulesofthefinancialandeconomicsystemsandcannotbeeasilyadjustedtoaneweco-nomicorfinancialsituation.Theyareapplicablewhencrisesoccuraccordingtorecurrentandknownpatterns.
1.2SymbolicandFuzzyRule-BasedSystems
Rule-basedsystemsandfuzzyrule-basedsystemsinparticularhavebeenusedinfi-nancialandeconomicdecisionmaking(seepapersin[12][13]).Themainadvantageofrule-basedsystemsisthattheirfunctioningisbasedonhumanexpertrules.Themaindisadvantageisthatthesesystemsarenotflexibleenoughtoreacttochangesinthereality.Changingtherulesusuallyisdifficult,andnobodycanarticulatetheperfectsetofrulesthatdonothavetochangeinafuturetime.
1.3ArtificialNeuralNetworks(ANN)
ExtendedstudiesofusingANNforfinancialDSShavebeendoneinseveralbooks(seeforexample:[12][13][49][54]).Generally,thesocallednon-parametricmod-elsprovedtooutperformthestatisticalmethods,especiallywhentheunderlyingruleswerenotknown,ortheychangeovertime.DifferenttypesofANNwereused,mainlymulti-layerperceptrons(MLP),radialbasisfunctions(RBF),andself-organisingfeaturemaps(SOM).
AMLPmodelandaRBFmodelonoptionpricing[16]provedtooutperformseveralothermodels,thatincludeadirectapplicationofBlack-Scholesformula,ordinaryleastsquares,andprojectionpursuit.ThetestdatawasthedailyS&P500futuresandoptionprices.Twoinputvariables–theratiostockprice/strikepriceandtimetomaturity,andoneoutputvariable-optionprice,wereused.Thismodelwasfurtherextendedintoamulti-modularANNmodelwiththeuseofhints[10].
In[5]asubstantialstudyofapplyingSOMtofinancialmarketsispresented.In[3]emergingandnewmarketsaremappedintoaSOMthatshowsgroups(clusters)ofsimilareconomies.
ThesofardevelopedandusedANNmodelsprovedtobeefficient,buttheydonotalloweasilyfordynamicon-linetraining,forchangingtheparametersinanon-linemode,forcombiningdataandknowledge(rules)intoonesystem.
1.4GeneticAlgorithms
Geneticalgorithms(GA)areheuristicmodelsthatarebasedongeneratingpossiblesolutionstoaproblemandevaluatingtheir“goodness”basedonagoodness(fitness)function(e.g.goalfunction)thathastobespecifiedinadvance.GAuseterminologyfromthenaturalselectionandevolutionofspecies.ThereareseveralstudiesofusingGAforeconomicandfinancialdecisionmaking(seealsochaptersinthisvolume).SoftwarebasedonGAsimulation,thatworksdirectlyondatainanExcelformathasbeenproduced[8].
ThemainadvantageofGAsisthattheydonotrequiremuchknowledgeontheunderlyingrules,formulas,etc.,butagoodnessfunctiontoevaluatehowgoodsolutionsare.ThemaindisadvantagesofGAsare:(i)theyarecomputationallyslow;(ii)theydonotnecessarilyprovidewiththebestsolutionastheyareheuristicallybased;(iii)theydonotworkinon-lineandrealtimemodes.
1.5ModelsBasedonDynamicSystemAnalysis
In[50]thestockmarketismodelledasacomplexdynamicsystemthatcanbeinoneoffourstatesprojectedinatwo-dimensionalspaceofgroupthinking-fundamentalbias:randomwalk,chaoticmarket,coherentbullmarket,coherentbearmarket.In[38][39]astockindexpredictionproblemisconsideredasequivalenttothepredic-tionofachaoticprocesswithdifferentcharacteristicsatdifferenttimescalesandahighfrequencyindexprediction(e.g.dailyprediction)beingattemptedafterthelowfrequencyone(e.g.,monthly,orannualprediction)isperformed.
1.6HybridSystems
Hybridsystemscombineseveraloftheabovemethodsintoonesystem[19][20].Theyachievethiscombinationeitherina“loose”way,e.g.differentmodulesinthesamesystemusedifferentmethods(seeexamplesofsuchsystemsin[12][13]),orina“tight”way-methodsaremixedatalowlevel,e.g.fuzzyneuralnetworks([18][29][42]).Thesemethodsarethemostpromisingamongthemethodsdiscussedabove,asthehybridsystemsintegratetheadvantagesofallthemethodscombined,e.g.dealingwithbothdataandexpertrules,usingbothstatisticalformulasandheuristicsorhints.
1.7WhatisMissingintheMethodsfromAbove?
Thesixgroupsofapproachespresentedabovehavebeenpartiallysuccessful,withmajorproblemsaslistedbelow:
Theydonotconsiderthecomplexityoftheprobleminawholewithmanyhier-archicallevelsfordecisionmakingthatincludeapplyinglow-levelprocessingandhigherlevelexpertknowledge;or
Theydonotconsideruncertaintiesatdifferentlevelsofinformationprocessingandcombiningthemorpropagatingtheminataskdependentwaytothefinaldecisionmakingblock;or
Theydonotapplysufficientvarietyoftechniquesandchoosethemostappro-priateforeachsub-task;or
Theydonotofferadjustmentofvariablesets,optimisationcriteria,rules,eveniftherealsituationchangesovertime.
2FromDSStoHIDSS
Hybridsystemscombinedifferenttechniquesofcomputationalintelligencewithtraditionalstatisticalmethods.HybridsystemsareespeciallysuitableforbuildingDSS.
Stockmarketindexpredictionisagoodexampleofacomplexproblemthatrequiresahybridsystem,asitisshownonthecasestudyoftheNZSE40stockindexin[19][38][39].SeveralmodulesareincludedintheDSSsystempresentedthereasthereareseveraltaskswithintheglobalone:datapre-processing(e.g.normalisation,movingaveragescalculation,etc);predictingthenextvaluefortheindex;predictinglonger-termvaluesfortheNZES40,finaldecisionmakingthattakesintoaccountrulesonthepoliticalandeconomicsituation;extractingtradingrulesfromthesystem-seeFig.1.Aneuralnetworkisusedtopredictthenextvalueoftheindexbasedonthecurrentandtheprevious-dayvalues.Thepredictedvaluefromtheneuralnetworkmoduleiscombinedwithexpertrulesonthecurrentpoliticalandeconomicsituationinafuzzyinferencemodule.Thesetwovariablesarefuzzybynature.Thefinaldecisionisproducedasafuzzyone,andasacrispone
-afteradefuzzificationprocess.AnothermoduleintheDSSfromFig.1isdevotedtoextractingfuzzytradingrules,whichareusedtoexplainthecurrentbehaviourofthemarket.
Anenvironment,calledFuzzyCOPE/1,thatcanbeusedtocreatehybridsys-tems,isdescribedin[19]andavailablefrominternetURLhttp://kel.otago.ac.nz/.Itconsistsofthefollowingmodulesthathavecompatibleinterfacesandcanbecon-nectedinaDSSasadecisionmakingsequencethatrepresentsthelogicoftherealdecisionmakingprocess:dataprocessingmodules(normalisation,fuzzification,fil-tering,etc.);multi-layerperceptron(MLP);self-organisingmap(SOM);fuzzyneu-ralnetwork(FuNN)asintroducedbyKasabovin[18][19][28];fuzzylogicinferenceengine(FLIE)basedonsimplefuzzyrulesofZadeh-Mamdanitype(Zadeh,1965);productionrule-basedsystemCLIPSandFuzzyCLIPSinparticular.TheFuzzy-COPE/1environmenthasbeenextendedtoFuzzyCOPE/3withtheinclusionofnewMLPandSOMlearningmodes,andnewmodesforlearning,ruleextractionandruleinsertioninFuNNs.ExamplesofhybridsystemsbuiltwiththeuseofFuzzy-COPEaregivenin[19].ThetwoenvironmentsFuzzyCOPE/1andFuzzyCOPE/3areavailablefromthefollowingWWWsiteandcanbeusedforbuildinghybridDSS:http://divcom.otago.ac.nz/infosci/kel/CBIIS.html(SoftwareFuzzyCOPE).
Fig.1.AnexampleofahybridDSSforstocktrading(from[19])
Thehybridsystemenvironmentsdevelopedsofar,andthehybridsystemsbuiltwiththem,havebeenveryusefultechniques,butthecomplexityandthedynamicsofthereal-worldproblems,especiallyinfinanceandeconomicsatpresent,requireevenmoreadvancedandsophisticatedmethodsandtoolsforbuildinghybridintel-ligentdecisionsupportsystems(HIDSS).Suchsystemsshouldbeabletochangeastheyoperate,alwaysupdatingtheirknowledge,andtorefinethemodelthroughinteractionwiththeenvironment.Somemajorrequirementstothepresentdayintel-ligentsystems(IS),andtotheHIDSSinparticulararegivenin[21]-[25].
Aframeworkforbuildingadaptiveintelligentsystems,calledECOS(evolvingconnectionistsystems)hasbeenrecentlyintroducedin[21]-[25],alongwithitsar-
chitecture,learningandevolvingalgorithms,ruleextractionandruleinsertionalgo-rithms,ofanevolvingfuzzyneuralnetworkEFuNN[23]-[25].EFuNNscanlearninanincremental,adaptivewaythroughone-passpropagationofanynewdataex-amples.EFuNNsaremuchfasterthanFuNNsandMLPsandcanlearndatainanon-linemode.EFuNNsdonothaveafixedstructure,onthecontrary–theystartevolving/learningwithnorule(hidden)nodesandtheygrowasdataispresentedtothem.Pruningofnodesandnodereductionisachievedwiththeuseoffuzzyprun-ingrules,e.g.:
IFanodeisnotmuchusedinadefinedperiod,ANDitisold,THENprobabilitytoprunethenodeishigh.
EFuNNshavethefollowingadvantageswhencomparedwithtraditionalMLPorSOMnetworks([24]:
1.theycanlearninanon-linemodeanynewdataastheyaremadeavailableovertime;
2.theycanworkinacomplexenvironmentwithchangingdynamics,e.g.astockindexsystemcanbeinarandomwalkstate,thenitmovestoachaoticstate,andthen-toquasiperiodicstate,andanEFuNNthatpredictsfuturestockvalues,learnsallthetimethenewbehaviourwithoutanyhumaninterventionforparameteradjustment.
3.theycanbeusedtomixexpertrulesanddataastherearealgorithmsforruleinsertionandruleextraction;
4.theycanclusterdatainanon-linemodewithoutpre-definingthenumberofclusters,orthedimensionalityandthesizeoftheproblemspace;
5.theycanbeusedforbothsupervisedandunsupervisedlearningmodes;assuper-visedsystemstheycanbeusedtopredictfuturevaluesoftheoutputvariables.ExamplesofusingFuNNsandEFuNNsforadaptive,intelligentdecisionsup-portsystemsforstockpredictionandloanapprovalaregivenin[26].Otherex-amplesinclude:imagerecognition[34];speechandlanguagerecognition[24][33];mobilerobotcontrol[24].
SimulatorsofEFuNNareavailablefromhttp://divcom.otago.ac.nz/infosci/kel/CBIIS.html(Software).
AnotherECOSalgorithm,calledEvolvingSelf-organizingMap(ESOM)[4],isproposedasavariationoftheSOMalgorithmbasedontheECOSprinciples.ESOMusesalearningrulesimilartoSOM,butitsnetworkstructureisevolveddynamicallyfrominputdata.SimulationshaveshownthatESOMlearnsfasterthanSOMwithasmallerquantisationerrorforfeaturevectors.
ECOS-basedmodulessuchasEFuNNsandESOMarepartoftheNewZealandRepositoryofIntelligentConnectionist-BasedSystems(RICBIS),whichalsointe-gratesmodulesfromtheFuzzyCOPEenvironments,aJavaversionofrule-basedsystemCLIPS(JESS),andaplatformindependentinterfacerunningasaJavaap-plet,whichallowsfordynamiccreationofnewmodulesduringtheoperationofanECOS,oranHIDSSinparticular.RICBISisavailablefromthefollowingURL:http://divcom.otago.ac.nz/infosci/kel/CBIIS.html(Software).
AnewexpertsystemarchitecturecalledAdaptiveIntelligentExpertSystems(AIES),basedondynamicgenerationofinterconnectedmodules(agents)fromtheRICBIS,isexplainedin[34].Itisinsharpcontrasttotheconventionalexpertsys-temsandDSSthatusuallyhaveafixedstructureofmodulesandafixedrulebase.AlthoughtraditionalexpertsystemsandDSShavebeensuccessfulinsomespecificandrestrictedareas,therewasno,orlittleflexibilityleftfortheexpertsystemtoadapttochangesrequiredbytheuser,orbythedynamicallychangingenvironmentinwhichtheexpertsystemandtheDSSrespectivelyoperated.
AIES,orHIDSSinparticular,consistofaseriesofmoduleswhichareagent-basedandaregenerated“onthefly”astheyareneeded.Fig.2showsageneralarchitectureofanAIES[34].Theuserspecifiestheinitialproblemparametersandtaskstobesolved.TheAIESthencreatesModulesthatmayinitiallyhavenorulesormaybesetupwithrulesfromtheExpertKnowledgeBase.TheModulescombinetheruleswiththedatafromtheEnvironment.TheModulesarecontinuouslytrainedwithdatafromtheEnvironment.RulesmaybeextractedfromtrainedFuNNsorEFuNNsforlateranalysis,orforthecreationofnewModules.TheModulesdy-namicallyadapttheirrulesetsastheenvironmentchangessincethenumberofrulesisdependentonthedatapresentedtotheModules.Modules(agents)aredynami-callycreated,updatedandconnectedinanon-linemode.TheycanberemovediftheyarenomoreneededatalaterstageoftheoperationoftheAIES.
User task specificationIntelligent Design InterfaceResultsSolutionKnowledgeBaseAgent 1Agent 2ModuleGenerationRepository of ModulesAdaptive Learning Data TransformationNeural NetworksFuzzy LogicGenetic AlgorithmEFuNNsData / EnvironmentDatabasesWeb pagesTime series Fig.2.Ablockdiagramofanagent-based,adaptiveintelligentdecisionsupportsystem–HIDSSthatusesthearchitectureofanAIES.
AverycomplexproblemofriskanalysisoftheEuropeanMonetaryUnion(EMU)system,establishedin1999tounifythecurrencyandtheeconomicdevel-opmentofelevenEuropeancountries,istheproblemdiscussedandhandledhere.TherestofthematerialherepresentsfirsttheproblemandthenaframeworkofaHIDSSforitssolution.Itthendevelopssomespecificmodulesanddiscussessomepreliminaryexperimentalandimplementationissues.
3TheProblemofRiskAnalysisintheEuropeanMonetaryUnion
Sinceitsconception,therehavebeenalotofmaterialspublishedondifferentissuesconcerningEMU.Globalpolicyrequirementsexist,suchasforeachparticipatingcountrytohaveadeficitlessthan3%ofitsGDPandexternaldebtlessthan60%oftheGDP.IntheEMUframework,theEuropeanCentralBank(ECB)isinchargeofthemonetarypolicy,withpriorityandresponsibilityforinflationcontrol.TheECBpublishesamonthlybulletincontainingarichsetofreal,monetaryandfinancialdataregardingtheEMUeconomies,othercountriesthatwouldbemembersoftheEMU,USAandJapan,inordertofollowtheevolutionoftheEMUinaworld-widecontext.Importantfinancialandeconomicparametersarerecordedandanalysedmonthly,quarterly,andannually,e.g.:Reservesandassets(gold,foreignexchange,other);Liabilities;StockmarketindexesoftheEMU,eachcountryseparatelyandthemajorworldindexes(DowJonesEUROSTOXX,S&P500–USA,Nikkei225–Japan);Interestrates;ExchangeratesEuro/US$,Euro/JY;Governmentbondyields(2,3,5,7and10years);Indexofconsumerprices;Industryandcommodityprices;GDP;Employment/unemployment;Saving,deficit/surplusratio(asa%ofGDP);Grossnominalconsolidatedebt(asa%ofGDP);Balanceofpayments(goods,services,income,capitalaccount).
OfaparticularinterestistheanalysisoftheEMUasadynamicclusterofeconomiesintermsofvolatility,variations,change,tendencies,andprediction(e.g.,monthly,quarterly,yearly).Therearesmallersub-clustersthatevolvewiththeeco-nomicdevelopmentofdifferentgroupsofEuropeancountriesandworldeconomiesthatshouldbealsomodelledandpredictedinrelationtotheEMUcluster.Alltheseclustersmovequicklyinadynamicallychangingproblemspace,thusmakingtheproblemoftheirpredictionandriskanalysisextremelydifficult.
Theproblemthispaperisdealingwithasacasestudy,canbedescribedasriskanalysisoftheEMUsystem.Here,moredetailsaregiven.
WiththeEMUineffect,countriessharingtheEuroasacommoncurrencyshouldovercometheriskofcurrencycriseswithintheEuroarea.However,theEuropeanmonetaryunificationhasnotruledoutpossibleepisodesoffinancialin-stabilityinEurope.TheMaastrichtTreatyimposesrigidconstraintsonpublicbud-getdeficits.Theseconstraintsareaimedatpreventinganexcessivedebtburdenonnationalgovernments,whichcouldleadtoaweakerEuro.Ontheotherside,EMUgovernmentscouldputpressureinordertoeasesuchconstraintsinthepresenceofexternalshocks,suchasthecrisisintheBalkans.Moreover,Europeanfinancialmarketsarenotimmunefromshocksoriginatingintheworldeconomy.
Inanextremescenario,riskofunilateralwithdrawalbyweakermembercoun-tries(otherwisecalledbreakawayrisk)cannotbeexcludedapriori,sincethepo-liticalcostsassociatedwithrespectofrigidfiscalandmonetaryconstraintsinananchoredregimecouldmakewithdrawalimperative.Anywithdrawalwouldbeadisruptiveevent,anticipatedand/orfollowedbyinstabilityandcrashesincreditandassetmarkets.CredibilityofEMUmembershipwillbeassessedandpricedbyfinan-
cialmarkets.IntheEMU,expectationsofbreakaway,unlikeexpectedrealignmentsorwithdrawalsintheExchangeRateMechanismoperatingfrom1979to1998undertheEuropeanMonetarySystems,willnolongertranslateintowiderinterestratedif-ferentialamongcurrencies,butintovariationofcreditspreadsappliedtosovereigndebtfromdifferentcountries.Holdersoffinancialassetswillbearanewsortofmacrorisk,whichwillbedifferentfromplaincurrencyriskandmoredifficulttoidentifyandmeasure.Studiesoncurrencycrises(e.g.[6])mustbereinterpretedandextendedtothenewcontext.Earlywarningsystemsusedbycentralbanksandspec-ulators,fedwithsignalsofrealandfinancialdis-equilibrium,mustberedesigned.Thegoalofthisprojectistodevelopacomputationalmodelforanalyzingandanticipatingsignalsofabruptchangesofvolatilityinfinancialmarkets.Thesys-temwillbeaimedatassessingthepossibilityofspeculativeattacksagainstspecificEMUmembercountries,prospectiveEMUmembersortheEMUareaasawhole.Potentialusersofthesystemincludemonetaryauthorities,assetmanagers,tradersonmoney,debt,currencyandstockmarketsandcorporatefinancialmanagers.Theconceptualmodelunderlyingthecomputationalmodelwillbederivedfromarepresentationoffinancialmarketsascomplexdynamicsystems,whosestochasticbehaviorisinfluencedbyexogenousshocksandendogenousuncertainty,thelattercausedbyinteractionamongmarketparticipants(degreeofconsensusandtendencytocrowdbehavior).InspirationforthisapproachcamefromapaperbyTonisVaga([50]).Thesystemwillbefedwithinformationfromdifferentsources,namely:-macroeconomicandmacro-financialindicators,suchastherealexchangerateoftheEuroagainstUSDollarandJapaneseYen,inflationdifferentials,Governmentdeficit,aggregateliquidityandsolvencymeasures(debt/assetratio,reserve/debtra-tio);
-riskspreadondebtsecuritiesissuedbysovereignandprivateborrowersinEMUcountries;
-riskappetiteofinvestorsinsecurities,measuredonthebasisofcorrelationbetweenreturnsin“risky”and“safe”markets(riskappetiteishighwhenriskiermarketsarerallyingversus“safe”marketsandthecorrelationishighlypositive);
-returnsandhistoricalvolatilityinfinancialmarkets(stock,currency,bond,money,derivatives);
-signalsoftrend,reversalandchangeofregimefromtechnicalanalysisoffinancialprices(movingaverages,resistanceandsupportlevels,relativestrengthindicators,etc.);thesesignalswillserveasproxyvariablesforendogenousuncertainty;
-impliedvolatilityinoptionmarketsandexpecteddistributionsextractedfromthem;
-recentepisodesofinstabilityinothercurrencyareasthatcanexertacontagioneffectontheEMUarea.
Thelogicofthesystemwillbedesignedasanextensionofexistingeventriskmodelsappliedtoforeignexchangemarkets([45]).Thesystemwillbetestedonasetofrecentepisodesofmarketcrash,andthenextendedtakingcareofuniquefea-turesofthenewEMUmonetaryregime.Thesystemwillproducearichinformativeoutput,consistingofdescriptivereportsandwarningsignals.
Firstly,thesystemwillprovideanintelligentinterfacetoinformationcurrentlyanalyzedbyeconomistsandtraders.Userswillbeabletonavigatethrougharichsetofeconomicandfinancialdatapresentedintablesandgraphs.ThepresentationwillfocusonphenomenapertainingtotheeconomicperformanceintheEMUarea,em-phasizingdivergencesamongcountriesandsustainabilityofMaastrichtconstraintsbothatthenationalandtheEMUlevel.
Secondly,thesystemwillprovidesignalsandindicatorsreflectingthelikelihoodofacrashinEMUfinancialmarkets.Anextensivesetofsymptomsoffinancialfragilitywillbemonitoredincredit,bondandstockmarkets.Neweventswillbecheckedagainsttypicalpatternsofevolutionoffinancialcrises.
Thesystemwillprovideavaluablesupporttoanalystsanddecisionmakersintwoways:(1)selectingrelevantinformationtobesubsequentlyanalyzedbyhumanexpertsand(2)extractingandsynthesizingsignalsfromavastarrayofinformationsources.
4CollectingRelevantDataforRiskAnalysisontheEMU.TheTrentoFinancialDataDictionary
Thedatacollectionisanimportantpartoftheresearchproject,becausetheresultsandthereliabilityofthehybridsystemdependcruciallyonthequalityoftherawdata.Infactahugeamountofdataisnecessarytomonitortheso-calledbreakawayriskintheEMU,inordertodetectthesolidityoftheEMUsystem,thedegreeofasymmetryandthepotentialexternalshocks.
Hugeamountofdataisbeingcollectedthatincludesdifferentlevelofinforma-tion:macroeconomicinformation;financialdata.MacroeconomicdataisavailablefrommanysourcesincludingEUROSTAT,theEuropeanCentralBankMonthlyBulletin,OECSandIMF.Avastamountofmacroeconomicdataismadeavail-ablethroughDatastream.Financialdataisavailablefromdifferenton-linesources,suchasDataStreamandReuter.Differenttime-scalesofdataarepresentinthedatarepository(e.g.,yearly,quarterly,monthly,daily,irregulartimeintervals,etc)
Itisnoteasytodealwiththisrelevantamountofdatawithoutpreparingatleastageneralinitialstructure.Forthisreasonwehavebuilttwomainprospects:the“sourcesdictionary”andthe“datadictionary”.
Thefirstprospecthasathreedimensionalstructure.Inthex-axiswehaveplacedthecountriesrelevantfortheEMUriskanalysis;wehavechosentheelevenpartic-ipatingcountries,thepotentialentrants,thebigworldplayers,andsomeemergingcountriestoproxyforanycontagioneffect.Inthey-axiswehavesetallthetypesofdatawhichcouldbeusefulfortheresearchproject.Thethirddimensioniscon-cernedwiththesourceofthegatheredinformation;everysinglevariablerelatedtoeveryinvolvedcountryhasbeencollectedbyaspecificsource.Thisaspectisimpor-tanttoevaluatemainlythereliabilityofthedata,butalsothedegreeofhomogeneityinthedataset.Infact,choosingthedatasourcewhichcoversthemostpartoftheinvolvedcountriesallowstoachievehighdegreeofsimilarityinthemodellingpro-cedureandintheupdatingtimingandmethod.Consideringthespecificpurposeof
theanalysis,werelyuponofficialstatisticsfromEurostatformostoftherequireddata.
Thesecondprospect,named“datadictionary”,isformedasatablewithcolumnsreportingthespecificfeaturesofeachdataseries;themostimportantonesarethefirstavailabledate,thefrequencyofcollection,andthemnemoniccode,whichisanalphanumericexpressionusefultoautomatetheinformationdownloadingprocess.Wehavedistinguishedtwobroadcategoriesofdatathatarebeingcollected.Thefirstlevelofinformationisconcernedwithmacroeconomicvariables;thesecondlevelismorespecificandregardsfinancialmarketdata.Athirdlevelofinforma-tion,connectedwithqualitativeknowledge,forexamplethepoliticalsituationorparticularnews,isnotformallyconsideredinthisfirstmodelimplementation.Thetypicalfeatureofthefirstgroupofvariables–macroeconomicdata–isthelowfre-quencyofcollection,whichismonthly,quarterlyorevenyearly,dependingonthespecificsector;anotherimportantfeatureisthepotentialvarietyofsourcesforthesamekindofdata.Athirdpropertyisthepotentialdifferentcalculusandupdatingprocedureforthesamesortofindices.Themostrelevantmacroeconomicdataaregenerallyavailableeitherashistoricaltimeseries,orasaconsensusforecast.
Thefinancialmarketvariablesarecollectedmorefrequently,evenonadailybasis,andareusuallyreleasedofficiallybytheexchanges.Inourresearchprojectwehavetriedtoconsidernotonlythepastevolutionofthevariousfinancialseries,butalsothemarketexpectationsimpliedinoptionprices;thereisagrowingliteraturedealingwiththisaspectwithtwomainapproaches.Thesimplerapproachisrelatedtothecalculationofimpliedvolatilityatdifferentmonetarydegreesasaforecastforexpectedvolatility.Inthesecondapproachtheunderlyingriskneutraldensityfunctionisextractedfromoptionmarketprices;itisveryusefulsubsequentlytomonitortheevolutionofthevariousmomentoftheprobabilitydistribution.
5TheEMU-HIDSS:ArchitectureandFunctionality
5.1AGeneralFrameworkoftheEMU-HIDSS
HereapreliminarydesignoftheEMU-HIDSSispresented(seeFig.3).Itisamulti-level,multi-modularstructurewheremanyneuralnetworkmodules(denotedasNNM),rule-basedmodulesandothermodulesareconnectedwithinter-,andintra-connections.EMU-HIDSSdoesnothaveaclearmulti-layerstructure,butratheramodular,“open”structure.Itisanevolvinghybridconnectionist-basedsystem([22]).
ThemainpartsoftheEMU-HIDSSaredescribedbelow.
(1)Featureselectionpart.Itperformsfilteringoftheinputinformation,featureex-tractionandforminginputvectors.Typicalfeaturesextractedfromtheinputdataeitherinanon-linemodeorfromthealreadystoreddatainfilesare:
Basicstatisticalparameters;
Probabilitydistributionandclusterinformation;
Movingaverages;
Wavelettransformations;
PowerspectrumandFFTfrequencycharacteristics;Mainfrequencies;Lyapunovcoefficients;Fractaldimensions;
Firstandsecondderivatives;Skewnessmeasures.
Theabovetransformationsareperformedinthepre-processing(featureextraction)modulesofthesystemappliedtocertaininformationinputstreams.
(2)Learningandmemorypart,whereinformation(patterns)arestored.Itisamulti-modular,evolvingstructureofneuralnetworkmodules(NNM).ThesemodulescanbebuiltwiththeuseofMLP,SOM,ESOM,FuNNs,EFuNNs,etc.Thereareseverallevelsofprocessinginthesemodulesintermsoftiming:
Dailyupdatedmodules,thesearemodulesthatdealwithdailyfinancialpre-dictionanddailyinputdata,e.g.MIB30prediction,Euro/US$exchangerateprediction,etc.
WeeklyupdatedmodulesMonthlyupdatedmodules
Yearlyupdatedmodules,e.g.longtrendprediction,andintermsoftheproducedresultsthatarepassedtothenextlevelhigherdecisionmodules:OnedayaheadpredictionresultsMonthlypredictionresultsYearlypredictionresults
Longertermpredictedresults
ThispartofthesystemwillincludeseveralmodulestodealwithdifferentlevelsandscalesofpredictionforeachoftheEuropeancountries,thebigeconomiesandtheemergingeconomies.Differentmoduleswilldealwith:
Predictingvalues(differencesinvalues)
Predictingshorttermtrends,e.g.oneweektrendifastockvaluewillbegoingupextremelyhigh,ormoderatelydown.
Predictinglongtermtrends,e.g.one-yeartrendifastockvaluewillbegoingupextremelyhigh,orcriticallydown.
(3)Higher-leveldecisionpartthatconsistsofseveralmodules,eachtakingdeci-siononaparticularproblem.ThemodulesreceiveinputfromtheNNMs,inputsformothervariablesinthedata,qualitativeinputfromusers,andmakedecisionsonpossiblecriticalsituationsthatmightoccurintheEMU.ThesemodulescansendafeedbacktotheNNMandthefeatureextractionpartofthesystemintermsofrequiringmoreinformation,differentscenariostobeexplored,differentfeaturesextracted,etc.Themodulesherearemainlyrulebasedwiththeuseofproduction
systems,flatfuzzyrules,FuNNsandEFuNNsthatcanrepresentbothfuzzyrulesanddata.Thereareseveralgroupsofinthispartthatinteractbetweeneachother,forexample:
(a)Agroupofmodulesthatdealwithaglobalriskevaluationproblems,e.g.:
ModuleevaluatingthedegreeofstabilityintheEMU;
Moduleevaluatingthedegreeofsymmetry/asymmetrybetweentheeconomieswithintheEMU;
ModuleevaluatingthepoliticalsustainabilityintheEMU;
ModuleevaluatingthedegreeofsuitabilityofanewcountryjoiningtheEMU;ModuleevaluatingthedegreeofinstabilityintheEMUbasedonexternalfac-tors(USA;Asia,Japan,India,Russia,wars,etc.)others
(b)Agroupofmodulesthatdealwithimportanteconomicfactorsandtheirresultscanbeusedeitherseparately,orbythemodulesoftype(1)above:
GDP
RateofunemploymentInternaldebtExternaldebt
ShorttermglobaleconomictrendsLongtermglobaleconomictrends
Solvencyratioofhouseholds,business,banksandgovernmentIndicationofreallocationofinvestmentsbyglobalassetmanagers
SharpmovementsofacertaincommodityinashortorinalongtermpatternSharpfallsinshorttermorlongtermtrends
Evaluatingandindicationofconsecutivephaseshappeningoveraperiodoftime,forexampleaneconomyhasbeeninthreeconsecutivephasesthatsignalacriticalsituationforthiseconomyandwillbeinfluentialfortheEMU
(4)Actionmodules,thattaketheoutputfromthehigher-leveldecisionmodulesandproduceoutputresultsorsendoutput(control)informationinanon-lineorinanoff-linemodetoinstitutionsthatshouldbealertedonacriticalsituation.
(5)Self-analysis,andruleextractionmodules.Thispartextractscompressedab-stractinformationfromtheNNMsandfromthedecisionmodulesindifferentformsofrules,abstractassociations,etc.HereFuNNs’andEFuNNs’ruleextractioncapa-bilitieswillbeutilised.
InitiallytheEMU-HIDSSwillhaveapre-definedstructureofmodulesandveryfewconnectionsbetweenthemdefinedthroughpriorknowledge.Gradually,thesys-temwillbecomemoreandmore“wiredthroughself-organisation,andthroughcre-ationofnewNNMandnewconnections.
Eachofthemodulesinthesystemarebuilt,orautomaticallygeneratedfromtheagentmodulesavailablefromRICBIS,e.g.:dataprocessingmodules(e.g.normal-isation,movingaverages,FFT,filtering,wavelettransformation,fractalanalysis,chaosanalysis,etc);productionrulesinJESS;fuzzyinferencerules,MLP,SOM,ESOM,FuNNs,EFuNNs,Hidden-MarkovModels,etc.
Learning ModulesFeatureSelectionModulesDecisionPartActionPartEnvironment(Critique)AdaptationNNMInputData• • • NNMAction ModulesHigherLevelDecis.ModulesResultsNewInputsNNMSelf analysis, Rule extractionModulesFig.3.AblockdiagramofthegeneralframeworkoftheEMU-HIDSSasanevolvingconnectionist-basedsystem(adaptedfrom[22]).
5.2EMU-HIDSS/1
Here,thefirstversionoftheEMU-HIDSSispresentedthatincludesasmallnumberofmodulesandgroupsconnectedbetweeneachotherasdescribedbelow.Group1:Modulesforhigher-levelriskanalysis
Herearemodulesthatmakedecisiononthediscrepancy/riskofasinglecountrytodevelopinadirectionawayfromtheexpecteddevelopmentoftheEMU.Fuzzyproductionrulesareusedfortheimplementationofthesemodules,suchas:
IFacountryispoliticallyunstable,orinwar,ANDthetrendofitsmacroeconomicdevelopmentinthelasttwoperiodsisawayfromthecentreoftheEMUcluster,THENtheriskthatthiscountrywillgoevenfurtherawayfromtheEMUishigh.Group2:ModulesfordiscoveringtrendsinthemacroeconomicdevelopmentoftheEMUclusterrelatedtothedevelopmentofotherclustersandothercountries.
HeretheconceptofEMUclusterisintroducedbasedontheEMUaggregateddataprojectedfromamultidimensionalspaceintoatwo(orathree)dimensionaltopologicalmapwiththeuseofself-evolving,self-organisingmaps.Thevectorsoftheused8parametersforthelast5-6yearofalltheEMUcountries,theotherEuropeancountries,someemergingmarketcountries,andalsotheUSAandJapan,aremappedintooneSOMorESOM.
Theneuron(thepointinthetwo-dimensionalmapspace)wherethecurrent-periodEMUvectorisprojectedisconsideredtobethecenteroftheEMUcluster.TheclusterincorporatesallpointswherethedataoftheindividualEMUcountriesaremapped.Theformoftheclusteranditsmovementfromoneperiodtothenextonecanbeobservedonthemapsandtheinformationwillbequantifiedbasedonthedistancebetweenthepoints.TheshapeoftheEMUclusteranditsdynamicscansuggestfurtherpoliticalandeconomicdevelopmentintheEMU.
ThemovementofthecenteroftheEMUclustercanbecomparedwiththemove-mentofthepointswherethedifferentcountriesaremapped.Aquantitativemeasureonthedifference(thedistanceinthetopologicalspace)betweendifferentcountriesfromtheEMU,andoutsidetheEMU,isevaluatedthatisusedasaseparateinfor-mationresultsaswellasaninputinformationtothehigher-leveldecisionmakingmodules.
DifferentclustersareformedonaSOM:theEMUcluster;theemergingeconomiescluster(e.g.,Poland);theclusterofthenon-Europeandevelopedcoun-tries(e.g.theUSA,Japan,Canada,Australia,NewZealand);theclusterofunder-developedcountries;theclusterofthedevelopednon-EMUcountries(e.g.theUK);theclusterofthedevelopingnon-EMUcountries(e.g.,Bulgaria,Romania).Avectoroffuzzymembershipdegreestowhicheachcountrybelongstoeachoftheclustersiscalculatedandtracedovertime.
Modulesfromgroup2coverdifferenttime-scales:annualmacroeconomicmap-ping,quarterlymacroeconomicmapandmonthlymacroeconomicmapping.
Thefollowingvariablesdescribethemacroeconomicstateofacountryinagivenperiodandallthevectorsforalltherelevantperiods(years,quarters,months)areusedintheunsupervisedtraining:GDP,debt,deficit,inflationrate,interestrate,unemployment,balanceofpayment,productiongap.
Group3:ModulesforevaluatingtrendsintheexchangerateEuro/US$
ThemainmoduleherepredictsthetrendoftheexchangeratebetweenEuroandtheUSdollar,butothermodulesdealwithnationalcurrenciesthatarenotpartoftheEMU.
Thefollowing10inputvariablesforexamplecanbeusedtopredicttherateR(t+1)ofEuro/US$,wheretisthecurrentperiod:R(t),R(t-1),Euro/JY(t),Euro/JY(t-1),ratioinflationrateinEMU/inflationrateintheUSAforboth(t)and(t-1)periods;ratiointerestratesinEMU/interestratesinUSAforboth(t)and(t-1)periods;ratioGDPinEMU/GDPinUSAforboth(t)and(t-1)periods.
Twotypesofmodelsareused-FuNNsandEFuNNs.Thetwomodelsusediffer-enttechniquesforextractingrulesandthemeaningoftheextractedrulesisdifferent.
IntherulesextractedfromFuNNstheconditionandconclusionelementshaveim-portancefactorsattachedtothempointingtotheimportanceofthedifferentpartsofarule.TherulesextractedfromEFuNNsarealsofuzzy,buttheypointtotheclus-tersintheinputandtheoutputspacethatarelinkedtogetherintherule.EFuNNsrequirelesstimefortrainingandcanbeupdatedveryquicklywithnewdatainanon-linemode.
Thepredictedtrendsoftheexchangeratescanbeusedeitherasseparateoutputresults,orasinputvaluesforthehigher-leveldecisionmodulesforbothquarterlyandmonthlytrendsprediction.
Group4:Modulesforevaluatingtrendsinmajorstockindexesandstockmarkets
Hereamapofthedifferentstatesofastockmarketaccordingto[50]iscreated.Thetransitionbetweenrandomwalkstate,chaoticstate,oracoherentstatewillbemodelledbytheuseofdifferenttechniques,thatinclude:hiddenMarkovmodels;evolvingfuzzyneuralnetworksEFuNNs;productionrules.
AnothermodulefromthisgroupevaluatesthevolatilityofmonthlytrendsintheDowJonesEuroSTOXX50index(DJE).Othermodulesevaluateweeklytrendsanddailyvalues.Thefollowing14inputvariablescanbeusedtoevaluatetheDJE,whereisthecurrenttimeperiod:DJE;DJE;;;Euro/US$;Euro/US$;Euro/JY;Euro/JY;Inflationrate;Inflationrate;GDP;GDP;Interestrate;Interestrate.
OthermodulesevaluatethetrendsinmajorEuropeanstockmarkets,suchastheItalianMIB30index(Milano).
6ImplementationandCurrentExperimentalResultswiththeEMU-HIDSS
TheimplementationoftheconceptualmodeloftheEMU-HIDSSfromsection5isaverycomplicatedtaskandalong-termobjective.Here,differentmodulesfromtheEMU-HIDSS/1conceptualmodelthatfollowthegeneraldescriptionandthelogicallinkspresentedintheprevioussection,aredevelopedandresultsareexplained.
6.1Group1ModuleforStatistically-BasedHigher-LevelRisk
Analysis
ThismoduletakesdynamicinputinformationfromtheclustermapsofthepreviouslevelofprocessingandcalculatestheEuclideandistancebetweeneachcountry’srepresentationvectorandthecenteroftheEMUclusteroverconsecutiveperiodsoftime(years,quarters).InthiswaythecountriesthataremovingawayfromtheEMUclusterareindicatedalongwiththespeedatwhichtheyaremoving.ForexamplethedistancebetweentheclustercenterofthemainEMUcountriesandItalyfor1997canbeevaluatedas3.8andfor1998as3.3,whilethesamedistancebetweenITandJPforthesameperiodscanbeevaluatedas1.2and0.7respectively(seeFig.4).
Fig.4.Theannualmapofthe15countriesaccordingto5characteristics(DBT/GDP,DEF/GDP,Inflationrate,Interestrate,Unemployment).ThecontourshowsthecenteroftheEMUclusterfor1998.
6.2Group2,SOMModulesforVisualExplorationofthe
AnnualandQuarterlyMacroeconomicDevelopmentoftheEMUClusterRelatedtotheDevelopmentofOtherClustersandOtherCountries
Thefollowing5variablesdescribetheannualmacroeconomicstateofacountry:DBT/GDP,DEF/GDP,Inflationrate,Interestrate,Unemployment.TheSOMmodelwastrainedon15countriesdatafrom1992till1998.ItisseenhowthepointsofthemapofthemainEMUcountriesandUSAaremovingfromlefttoright.Fig.4showsalsothecontoursurroundingthecentreoftheEMUclusterfor1998.ItisobviousthatthefollowingEMUcountriesarewithinthecluster:OE,NL,DK,IR,UK,SD,BD,FRinadditiontotheUSAandtheUK.Butfourcountriesareoutsideit(IT,BG,GR,ES)withonlyESmovingintotherightdirectiontowardstheEMUclustercenter.
Fig.5showsthedirectioninwhichItaly(IT)ismovingovertheyearsfrom1992till1998.
Fig.5.Iso-graphsofthe15countriesannualdevelopmentmapandthedirectionofthedevel-opmentofItaly.
AnotherSOMmoduleistrainedonquarterlydataofthefollowingthreevari-ables:Inflationrate,Interestrate,Unemployment.Fig.7showsthemapandthelineofthequarterlydevelopmentofGermany(BD).
TheSOMmodulesaresuitableforvisualexplorationasSOMsprovidewithanefficienttoolforvectorquantisation,i.e.turningann-dimensionalspaceusuallyintotwodimensionalspacepreservingthesimilaritybetweentheinputvectorsacrossalltheattributesastopologicaldistancebetweenpointsofthemap.SOMshavesomedifficulties,mainly:(a)theyhaveafixedstructure;(b)theycannottoleratemissingvalues;(c)learningusuallytakesalongtime.
InordertoovercomethelimitationsoftheSOMs,hereevolvingSOMmodulesarealsoused.
6.3Group2,ESOMModuleforDynamicMappingof
MacroeconomicAnalysis
AnotherannualmapisevolvedwiththesamedatasetasintheSOMmodulesandisshowninFig.8.ThemapisfirstclusteredusingESOMalgorithm,andthenpro-jectedontoatwo-dimensionalplaneforvisualisationusingSammon’salgorithm.Hencebothclusteringanddatastructureareavailablewithinthemap.ThelayoutoflabellednodesisverysimilartothatofFig.4,buttheESOMmapgivesmore
(a)
(b)
Fig.6.Componentanalysis:(a)Thefirstcomponent(DBT/GDP)fromthemapoffigs.4and5showthatinthisrespectBG,ITandGRareinasimilarposition.SD97andSD98forman“island”intheEMUclusterwithagoodtendency.(b)TheInflationcomponentshowsadramaticincreaseinGreecefrom1996to1997and1998.
Fig.7.Thecompletemapofthequarterlydevelopmentofthe15countriesfrom1995till1999andthelineofthedevelopmentofGermany(DB).
Fig.8.TheESOMclustersofthemacroeconomiesofEMUcountries.
10.90.80.70.6SW940.50.40.30.2
Distribution of Rule Nodes in Input-Input Space (
IR98Training )
FN98
DK982
IR97US98
SD98
JP9224
DK97
UK98
US97IR96
8NL98DK96NL97
SD97
US96
IR94JP93
17OE97UK97OE92OE98ES98NL961SD96IR95DK95PT98US95JP94DK92
FR98BD98PT97IR92IR9322BD94ES97DK94
BD97DK93BD9216PT92US94
NL93PT96JP97
FR97BD96BD9514JP95BD93OE96FN96NL95NL94US93NL927FR92JP96OE93ES9223
UK96FR96ES96US9210
OE94OE9511FN95
FR95UK95
FN92PT9512PT94FR94FR935JP98FN94PT93UK92
18ES94
UK94
ES93
ES95
21SD95UK93SD92FN9320
FN97
BG98
BG97
GR984
3
IT98IT97
BG96
6GR97
15
BG95BG94
9
GR96
IT96IT95
BG92
BG93
IT92
SD94
IT93
IT94
19
GR94
13GR95
0.10
0
SD93
0.10.20.30.40.50.60.70.80.91
Fig.9.ClusteringofannualdatawithEFuNN.
explicitinformationonsimilarityofcountryperformancewhichcanberepresentedbydistancebetweenthenodes.
Byclippingweakconnectionsusingadistancethreshold,asshowninFig.8,clustersintheannualmacroeconomicperformancedatacanberevealed.Herewefindtwomajorclusters,theEMUclusterwithcountrieslikeFR,BD,FN,PTetc.plusUKandUS,andthefall-outclusterwithGR,IT,andBG.
6.4Group2,EFuNNBasedModuleforPredictionand
ClusteringoftheAnnualandQuarterlyEconomicDevelopmentofthe15Countries
HereEFuNNsareusedtodevelopmodulesthatcanpredictvaluesforallthefiveselectedattributesintheannualdevelopmentandthethreeselectedattributesforthequarterlydevelopment.Suchmodulesaretheannualmoduleandthequarterlymodule.Thefirstonetakestwoinputvectorseachof5variables(atthetimemomentand)andcalculatesoneoutputvectorof5elementspredictingwhatthevaluesforthesevariableswillbe.Fig.9showstheclusteringoftheannualdata(displayedwiththefirsttwovariablesDBT/GDPandDeficit/GDP)achievedintherulenodesofanevolvedEFuNN.ItisclearthatIT,GRandBGformaclusterwithhighDBT/GDPvalueandDEF/GDPrunningfromlowtohighvalues.TheclusteringofdatasamplesarequitesimilartothatoftheSOMmodule,butitismuchmorequicklylearnedintheone-passlearningEFuNNmodule.
Fig.10showstheannualEFuNNpredictorforthe15countriesruninanon-linemodetopredicttheDBT/GDPvaluesannually.
Fig.10.AnnualEFuNNpredictorforpredictionofannualDBT/GDPvalues.
Fig.11.Quarterlypredictorforthe15countriesandtheon-linepredictionofthefirstvariable(Inflationrate).
RulescanbeextractedfromEFuNNsthatarefuzzy,andtheypointtotheclustersintheinputandtheoutputspacethatarelinkedtogetherintherule.EFuNNsrequirelesstimefortrainingandcanbeupdatedveryquicklywithnewdatainanon-linemode.
Fig.11showsthe15countriesquarterlypredictor,whichcanpredictvaluesofthethreeselectedvariablesInflationrate,Interestrate,UnemploymentforanyofthecountriesinthefollowingquartergiventhedataforthecurrentandpreviousquarterandalsotheannualDBT/GDPandthepreviousyearDBT/GDPareentered.Thefirstoutputvariableisshownaspredictedinanon-linemode.Thesystemimprovesitspredictionovertime.
6.5Group4,EFuNNModuletoEvaluateTrendsinthe
ExchangeRateEuro/US$
ThemainmoduleherepredictsthemonthlytrendoftheexchangeratebetweenEuroandtheUSdollar.Thefollowing10inputvariablesareusedinordertopredicttherateofEuro/US$,whereisthecurrentperiod:,,Euro/JY,Euro/JY,ratioinflationrateinEMU/inflationrateintheUSAforbothand
periods;ratiointerestratesinEMU/interestratesinUSAforbothandperiods;ratioGDPinEMU/GDPinUSAforbothandperiods.
6.6Group4,EFuNNModuletoEvaluateTrendsintheDJE501MajorStockIndex
ThismoduleevaluatesthemonthlytrendsintheDowJonesEuroSTOXX50index(DJE).Thefollowing14inputattributesareusedtoevaluatetheDJE,whereisthecurrenttimeperiod:DJE;DJE;;;Euro/US$;Euro/US$;Euro/JY;Euro/JY;Inflationrate;In-flationrate;GDP;GDP;Interestrate;Interestrate.
Besidesthemoduleslistedabove,severalothermodulesarecurrentlyunderdevelopment.
7ConclusionsandDirectionsforFurtherResearch
Aframeworkofhybridintelligentdecisionsystemispresentedinthepaper.Byapplyingarepositoryofintelligentinformationprocessingmodulesimplementedinanagent-basedarchitecture,acasestudysystemEMU-HIDSSisbuiltforriskanalysisandpredictionofevolvingeconomicclustersinEurope.
TheEMU-HIDSSisdesignedtobeusedatdifferentlevelsofanalysisanddecisionmakingabouttheEMUandabouttherelevantchangesintheeco-nomicclustersofEuropeandtheworld,thatincludes:theEuropeanUnionlevel;theglobalworldeconomieslevel;nationallevel;companyandbanklevel.DataandsomeofthedevelopedmodelsareavailablefrominternetURL
http://divcom.otago.ac.nz/infosci/kel/CBIIS.html(Software-FinancialRiskAnaly-sisandPrediction).
Acknowledgements
ThisworkissupportedbyaresearchgrantoftheDepartmentofComputerandMan-agementSciences,UniversityofTrento,andalsobyagrantPGSF-UOO808fundedbytheNewZealandFoundationforScience,ResearchandTechnology(FRST).
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