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    E D I T E D B Y PAT RI C I A M C D E RM O T T AN D LAU RE L ALLE N D E R

    ADVANCED DECISI ON ARCHITEC TURES

    FOR THE WARFI GHTE R:F O U N D AT I O N S A N D T E C H N O L O G Y

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    i

    A D VA N C E D D E C I S I O N A R C H I T E C T U R E S

    F O R T H E WA R F I G H T E R :

    F O U N D AT I O N S A N D T E C H N O L O G Y

    E D I T E D B Y PAT R I C I A M C D E R M O T T

    A N D L A U R E L A L L E N D E R

    This book, produced by the Partners of the

    Army Research Laboratory Advanced Decision Architectures

    Collaborative Technology Alliance, also serves as the

    Final Report for DAAD19-01-2-0009.

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    SECTIONI.COLLECTING,

    PROCESSING,

    AND

    DISTRIBUTING

    BATTLEFIELD

    INFORMATION

    SECTIONI

    COLLECTING,PROCESSING,ANDDISTRIBUTINGBATTLEFIELD

    INFORMATION

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    14 SECTIONI

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    15

    Chapter1

    1.

    DYNAMICNETWORKANALYSISAPPLIEDTOEXPERIMENTS

    FROMTHEDECISIONARCHITECTURESRESEARCHENVIRONMENT

    KathleenM.Carley,Ph.D.

    CarnegieMellonUniversity,Pittsburgh,PAMichaelK.Martin,Ph.D.

    CarnegieMellonUniversity,Pittsburgh,PAJohnP.Hancock

    ArtisTech,Inc.,Fairfax,VA

    INTRODUCTION

    ADACTAresearchisproducingexperimentalresultsfromsimulations

    ofintermeshednetworksofwarfightersandbattlefieldsurveillance

    assets.Thesenetworksformacomplexsystemwithbehaviorsthat

    emergefrompatternsofinteractionamongconstituententities.Thesim

    ulatedinteractionsarespatiallysituated,temporallydistributedcommu

    nicationsamongpeople,robots,andsoftwareagents.Ingeneralterms,

    thecomplexsystempartsofwhichweaddressinthispapercanbe

    conceptualizedasatwolevelmetanetworkthatincludesinteractions

    amonghumanagentsatonelevel,interactionsamongartificialagentsat

    anotherlevel,andcrosslevelinteractionsbetweenhumanandartificial

    agents.

    TheissueaddressedinthispaperisDynamicNetworkAnalysis(DNA)

    ofsystembehavior.Forthepurposesofthischapter,wearenotinter

    estedinexaminingtheperformanceofonesystemrelativetoanother.

    Althoughthis

    type

    of

    comparative

    analysis

    can

    be

    useful

    for

    researchers

    orsystemdesigners,itisofquestionableusetowarfighters.Instead,we

    areinterestedinanalysesthatproducetacticallyrelevant,actionable

    resultsthathighlightthestrengthsandweaknessesinthesystembeing

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    16 CARLEY,MARTIN,ANDHANCOCK

    observed.Tobeuseful,theanalyticalresultsmustfostertacticalinsight

    andstimulatebattlefielddecisionsthatprudentlyinfluencefuturesys

    tembehavior.

    Tothisend,wedescribetwocasestudiesthatapplyDNAtothesim

    ulatedbattlefield

    data

    being

    generated

    by

    experiments

    in

    the

    Decision

    ArchitecturesResearchEnvironment(DARE).Thefirstcaseinvolvesinter

    ceptsofsimulatedcommunicationsamonghumanagents,whichwe

    frameasanexerciseinadversarialreasoning.Thesecondcaseinvolves

    simulatedcommunicationsamongsurveillanceassets(i.e.,software

    agentsandrobots),whichweframeasanexerciseinunderstandingthe

    automatedcontrolofaPersistentCoordinatedVideoSurveillance(PCVS)

    system.Together,webelievethecasestudiesdemonstratehowDNA

    (Carley,2002)

    can

    foster

    tactical

    insight

    in

    complex

    multi

    entity

    scenar

    ios.TheyalsodemonstratethatthecombinationofDNAtechniques

    requiredfortacticalinsightmayvaryaccordingtothetypeofnetwork

    beinganalyzed.Finally,theyshowhowDNAassistsinthedevelopment,

    understandingandtuningofsoftwareagentsystems.

    ANALYTICALAPPROACHOneapproachtoanalyzingsystembehavioremploysmainstream

    statisticaltechniquesonsummarymeasuresofperformance(e.g.,percentoftargetstracked,percentofprioritytargetstrackedwithaccept

    ableaccuracy,trackcorrelation,etc.).Thistypeofanalysis,however,

    doesnotfullyexploittheinformationgeneratedinDAREexperiments

    orbybattlefieldsurveillanceingeneral.Moretothepoint,itprovideslit

    tleinsightintotheidentificationofleversinthenetworksunderlyingsys

    tembehavior.Onceidentified,leverscanbeusedtodetermineactionsto

    taketoinfluencefuturesystembehavior.

    DNAprovides

    an

    alternative

    analytical

    approach

    that

    compliments

    mainstreamstatistics.WithDNA,thefocusshiftsfromaggregatemea

    suresofperformanceforacollectionofbattlefieldentitiestotheperfor

    manceimpliedbythestructureofrelationsamongbattlefieldentities.

    Thisshiftistheessenceofwhatitmeanstoviewthebattlefieldfroma

    networkscienceperspective.Thatis,fromanetworkscienceperspective

    wearelessconcernedwithwhatisnormal(e.g.,averages,dispersions)

    aboutentitiesinthebattlefield(e.g.,people,places)andmorecon

    cernedabout

    detecting

    substantive

    patterns

    in

    the

    observed

    relations

    amongentities.TheemphasisonthestructureofrelationsinDNAmakes

    itparticularlywellsuitedtothedetectionofanomaliesandexceptions

    (e.g.,centralities,exclusivities)theleverswithpotentiallylargeinflu

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    DynamicNetworkAnalysis 17encesonsystembehavior.DNA,therefore,fostersscrutinyofstrengths

    andvulnerabilitiesintherelationsamongbattlefieldentities(i.e.,the

    observedsystem).WithaDNAmodel,wecanidentify(amongother

    things)implicitgroupsofentities,keypeopleandlocations,andopera

    tionallysignificant

    time

    frames.

    We

    can

    even

    begin

    to

    infer

    relations

    amongentitieswherenonehavebeenobserved.

    Networksciencehasbeenhamperedhistoricallybyadominantly

    socialperspectivefocusingonwhointeractswithwhom.However,Carley

    (2002)arguedthatthesesocialnetworksexistwithinanecologyofnet

    worksthatcanusefullybecharacterizedintermsofthedynamicsofthe

    relationsamongthewho,what,where,how,andwhy.Thisisknownas

    themetanetworkperspective.*ORA(e.g.,Carley,Columbus,DeReno,

    Reminga&

    Moon,

    2008)

    is

    adynamic

    network

    analysis

    package

    that

    can

    beusedtoassessmultimode,multiplexnetworks;identifykeyplayers,

    groupsandvulnerabilities;enablecomparisonoftwoormorenetworks;

    andfacilitatereasoningaboutspatiotemporalnetworks.

    *ORAsupportsanalysisofdynamicnetworksinmanyways: (1)com

    parisonsoftemporallyorderedsnapshotsofstaticnetworks,(2)statisti

    calchangedetectiononsequencesofnetworks,(3)trailanalysisfortrail

    dataandconversionoftraildatatonetworks,(4)simulationofchangein

    networks,and(5)comparativestaticsforimmediateimpactassessment.

    Herein,wemakeuseofstatisticalchangedetectionandtrailanalysis,

    alongwith*ORAsvisualizationcapabilities.

    CASESTUDY1:TERRORISTSINADELPHIThescenarioforcasestudy1wasframedasinterceptsofsimulated

    communicationsamongagentsrepresentingterroristsandnoncomba

    tants(e.g.,pizzadeliveryguys).Theagentscommunicatedviaphoneand

    emailas

    they

    moved

    about

    the

    Adelphi

    region.

    DataGenerationThedataweregeneratedbyArtisTechsAlgoLinksimulator.The

    AlgoLinksimulatorwasoriginallydevelopedtotestthecapabilitiesof

    messageanalysistoolstosupportintelligenceanalysisrequirementsin

    battlefieldcommunications.AlgoLink(seeFigure1.1)facilitatescustom

    constructionof

    entity

    networks

    that

    follow

    specified

    communication

    structures,times,places,durations,andbehaviors.Itgeneratesboththe

    foreground(networkofinterest)andthebackgroundcommunicationas

    specifiedandstitchesthemtogetherintoasinglecommunicationrecord.

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    18 CARLEY,MARTIN,ANDHANCOCK

    Backgroundcommunicationisbothstructured(e.g.intermingledhierar

    chicalandsocialorganizations)andrandomasspecifiedbythehuman

    simulationoperator.AlgoLinkusesrealisticcommunicationandorganiza

    tionaldata,timing,andmorphologiesbutcontainsnoinformationabout

    anyreal

    person

    or

    organization.

    Figure1.1TheAlgoLinkmessagesimulatorinterfaceThedatasetcreatedforthisexperimentwasgeneratedbyArtisTech

    stafflookingforwardtosystembasedIntelligentAgentcommunication

    behavioranalysis.Theentitiesofinterestwereorganizedintoasmall

    numberofcellsthatwereuniquelyconnectedandstitchedintoa

    largerbackgroundcommunity. Thedatasetwasgeographicallycen

    teredontheARLAdelphicampusbecausetheARTEMISprojectiscoordi

    natedwiththeARLComputationandInformationSciencesDirectorateresearchsystems.Thesimulatedsocialstructurewasmorphologically

    similartoamediumsizedcommunityofintelligentagentsactingwitha

    specificpurposeinabattlefieldCommand,Control,andCommunications

    (C3)system.Tosimulateaneventthatstimulatesthecommunication

    network,aspikeincommunicationvolumewasinsertedataselected

    time.TheAlgoLinkgenerateddatasetwasarapidwaytoassessthefea

    sibilityofcollaborationbetweentheARTEMISPCVSandCASOSteams.

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    DynamicNetworkAnalysis 19Analysis

    TheAlgoLinkoutputwasdeliveredasanXMLfilecontaininga

    sequenceofcommunicationsrecords.Eachsimulatedcommunication

    recordidentified

    the

    sender,

    the

    receiver,

    the

    time

    the

    communication

    occurred,itsduration,andwhetheritscontentwasoperationallyrele

    vant,irrelevant,orambiguous.Italsocontainedlatitudeandlongitude

    forthepositionofthemobilesendersandreceiversduringeachcommu

    nication.

    Ouranalysisstrategyinthiscasecanbegenerallydescribedasan

    overviewandzoom.Thatis,wefirstexaminedthegeneralcontextof

    communicationsactivities,andthendrilleddowntodetermineimpor

    tantagents,

    time

    frames,

    and

    locations.

    The

    subset

    of

    *ORA

    capabilities

    thatprovedparticularlyusefulhereincludedgeospatialvisualization,key

    playeridentification,changedetectionanalysis,andthecorrelationof

    standardnetworkandgeospatialvisualizations.

    Using*ORAsgeospatialvisualizationcapabilities(e.g.,Davis,Olson,

    &Carley,2008)weexploitedthepresenceoftimevarying,geolocated

    attributesoftheinterceptedcommunicationstodiscoverthescenario

    involvedsuspiciousentitiesfleeingtheAdelphiarea(seeFigure1.2).

    Figure1.2AgentsfleeingAdelphioverthetimecourseofthescenario

    Usingafuzzygroupclusteringtechnique,FOG(e.g.,Davis&Carley,

    2008),wefoundthatthesuspiciousentitieswereorganizedintofive

    groupswithsharedmembers(seeFigure1.3).Theinterstitialmembers

    arelikelytocontainthecoordinatorsandleaders.

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    20 CARLEY,MARTIN,ANDHANCOCK

    Figure1.3Agentsorganizedin5groupsthatsharemembers

    Todrilldown,wefirstused*ORAsKeyEntityReporttoidentifythe

    threeagentsmostcriticaltooperations(seeFigure1.4).Becausethe

    datawereaboutcommunications,twodifferentcentralitymeasures

    wereuseddegreecentralityandbetweennesscentrality.Degreecen

    tralitymeasureswhoisconnectedtomostothers(i.e.,theactormost

    likelytobeintheknow).Betweennesscentralitymeasureswhois

    mostlikelytobeonallthepathsbywhichinformationflows(i.e.,the

    actormostlikelytobeinfluential).Thisenablednarrowingourfocustoa

    smallgroupofleadersinsteadoffocusingonthesetofinterstitialmembers.

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    DynamicNetworkAnalysis 21

    Figure1.4KeyEntityReportidentifies3importantagents

    Wenext

    asked,

    is

    something

    happening?

    One

    way

    of

    answering

    this

    istoseewhetherthereisachangeinstandardbehavior.Usingthe

    ChangeDetectionReport(seeFigure1.5),weidentifiedperiod3asthe

    timeframeinwhichoperationsmostlikelyoccurred.

    Figure1.5ChangeDetectionReportsignalstimeperiod3isdifferent

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    22 CARLEY,MARTIN,ANDHANCOCK

    Thenetworkchangedetectionanalysis(McCulloh&Carley,2008;

    2009;McCulloh,Webb,Graham,Carley&Horn,2008)extendschange

    detectionfromoperationsresearch,whereithasbeenusedonvariable

    leveldata,

    to

    relational

    data.

    This

    is

    astatistical

    approach

    for

    detecting

    smallpersistentchangesinorganizationalbehaviorovertimeusingsta

    tisticalprocesscontroltechniquesappliedtonetworksummarystatistics.

    Period2wasthepointatwhichorganizationalbehaviorchanged,leading

    toradicaldifferencebyperiod3.Thisappearstohavebeenaplanning

    executionphaseshift.

    Examinationofindividuallevelmetricsforthethreekeyplayersand

    networklevelmetrics(e.g.,centrality,betweenness,efficiency,connect

    edness)corroborated

    our

    interpretation

    that

    period

    3was

    operationally

    significant.Individuallevelmetricsindicatedthatactor286engagedin

    extensivecoordinationatperiod2,passingthereignsofcontroltoactor

    652atperiod4(seeFigure1.6).

    Figure1.6Individuallevelmetricsconvergeonperiod3

    Examinationofnetworklevelmetrics(seeFigure1.7)showedthatthe

    groupwasgenerallyaverydistributedstructurethatcoordinatedintoa

    centrallycontrolled,moreefficient,unitatperiod3.Then,itwentback

    toits

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    DynamicNetworkAnalysis 23

    Figure1.7Networklevelmetricsconvergeonperiod3

    standardformandbecamemorehiddeninthesociocommunication

    environment.

    Havingidentifiedthekeyplayersandtimeperiod,wefocusedour

    analysesondiscoveringwhatmayhavehappened.Examinationofthe

    agentxlocationnetworkforperiod3(seeFigure1.8)indicatedalarge

    clusterofsuspiciousentitiesintheAdelphiarea(includingkeyplayer,

    Agent286),afairlylargeclusterofsuspiciousentities(includinganother

    Figure1.8Agent

    xLocation

    Network

    for

    period

    3

    keyplayer,Agent97)inwhatappearstobeastagingarea,anapparent

    waypointbetweenthestagingareaandtheclusterofsuspiciousentities

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    24 CARLEY,MARTIN,ANDHANCOCK

    inAdelphi(alsovisitedbyAgent97,whoseemstobealiaison),anda

    runner(keyplayer,Agent652)whovisitsmanylocationswithfewsuspi

    ciousentitiespresent.

    Anotherkeyadvance,developedaspartoftheCTA,wasthecapabil

    ityto

    move

    between

    trail

    data

    who

    was

    where

    when

    and

    networks.

    Whenweexaminedthetrailsvisualizationforperiod4(i.e.,theperiod

    immediatelyfollowingtheapparentoperation,perhapsaperiodofinitial

    surveillance),wesawthatthethreekeyplayerswereneverinthesame

    placeatthetime;Agent652wasagainrunning,whereastheactivitiesof

    Agents97and286wererestrictedtooneortwoareas.Theapparent

    coordinationhandofffromAgent286toAgent652isrelatedto652s

    increaseinspatialmovementandcoordinationneededduetoincreased

    movement.In

    the

    trails

    visualization

    (see

    Figure

    1.9),

    time

    progresses

    downtheyaxis.Geographicregionsformverticalbinsalongthexaxis.

    Arrowsareplottedasagentsmovefromregiontoregion(orwithin

    regions),andinthiscasearecolorcodedtothethreekeyplayers.

    Figure1.9*ORALoomvisualizationoftrailsfor3keyplayersduringperiod4

    Finally,correlatingastandardagentxlocationnetworkvisualization

    withageospatialvisualizationfortheendofthescenariowefoundthat

    Agent286wasalonewithasinglemovementbetweentwolocationsin

    Adelphi,Agent97washoledupwithasizablegroupofsuspiciousenti

    tiesnorth

    of

    Adelphi,

    and

    Agent

    652

    was

    alone

    but

    on

    the

    run

    (see

    Figure

    1.10).

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    DynamicNetworkAnalysis 25

    Figure1.10Correlationofagentxlocationnetworkandgeographiclocationatsce

    narioend

    Giventhepatternofcommunicationsandmovementduringthesce

    nario,twocoursesofactionsappearreasonable: (1)scourAdelphifora

    bomb,IED,etc.plantedduringoperationsinperiod3,or(2)goafterdis

    persedsuspiciousentities.Withrespecttoaction2,Agent286maybean

    easytarget

    with

    direct

    knowledge

    of

    the

    operations

    that

    occurred

    during

    period3.TargetingthelocationwhereAgent97ishiding,however,will

    yieldmoresuspiciousentities.Notethatthesimulateddatadoesnot

    includecommunicationscontentsospecificationoftheeventisnotpos

    sible,buttheappliedDNAanalysisaccuratelyidentifiedthetime,place,

    andleadentitiesinthesimulation.

    CASESTUDY2:MOVEMENTINTHEPERIMETERThescenarioforthiscasecenteredonanautomatedsurveillance

    system(i.e.,theARTEMISPCVSsystem)thatisresponsibleforidentifying

    movingentitieswithintheperimeterofaBlueForce researchcom

    pound.Thesystemdividestheperimeterintofourareasofresponsibility,

    whereeachareaisassignedtoaTaskingAgentthatisresponsiblefor

    surveillance(seeFigure1.11).TaskingAgentsgetsimulatedmovement

    reportsfromsimplevideoanalysisalgorithms.TaskingAgentsthenprior

    itize

    targets

    and

    assign

    mobile

    robotic

    assets

    to

    pursue

    and

    identify

    the

    targets.

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    26 CARLEY,MARTIN,ANDHANCOCK

    Figure1.11Tasking

    Agent

    Areas

    DataGenerationThedataweregeneratedbyArtisTechsARTEMISPCVSsystemproto

    type(seeFigure1.12).Thisprototypeuseshundredsofsmallreasoning

    Figure1.123DViewofARTEMISPCVSscenarioontheGISARLAdelphitestbed

    model

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    DynamicNetworkAnalysis 27algorithmsencapsulatedinsoftwareagents.Theagentscommunicate

    withhumans,agents,andothersystemelementsandevencreateand

    deleteotheragentswithfrequenciesthataredependentontheirreac

    tionstothesensedenvironment(simulation).

    Theparticular

    experimental

    run

    analyzed

    here

    was

    conducted

    to

    determinewhetherTaskingAgentreasoningandcommunicationabout

    sharingmobileroboticassetswasfunctioningasexpected.Thescenario

    includedashorttimeofquiescenceinthecompound,followedbythe

    injectionofarelativelylargenumberofmovingtargetsthatmoved

    aboutthecompoundusingreasonablepathsbutfreelycrossingareasof

    surveillanceresponsibility.Whentargetscrossareasofresponsibilitythe

    complexityofreasoningincreasesandrequiresthatTaskingAgentstrans

    fer(handoff)

    tracking

    and

    even

    possibly

    lend

    robotic

    assets

    to

    other

    TaskingAgents.Theactoflendingtheassetinvolvescommunicationto

    notifyanadjacentTaskingAgentofanincomingunidentifiedentity,

    andamultimessageTaskerGlobalTaskerhandshaketotransfercon

    trol.Thereweretwoofthesehandoffeventsinthescenario.Thissce

    nariowasasimpleonetofacilitateearlycollaborationbetweenARTEMIS

    andCASOSstaff.

    Analysis

    Aswithcasestudy1,thedataweredeliveredasanXMLfilecom

    prisedofasequenceofcommunications.Thecommunicationswere

    betweensoftwareagentsorsoftwareagentsandrobots.

    Althoughthedatasetsweresuperficiallysimilar(i.e.,logsofcommu

    nicationsrecords),casestudy2presentedseveralchallengesnotpresent

    incasestudy1.Thesechallengesaroseprimarilybecausethedatafor

    thiscasewererelativelyimpoverished.DNArequireslargedatasetsand

    wedid

    receive

    more

    data

    for

    case

    study

    2than

    for

    case

    study

    1.

    However,

    theextradatawereoflittlebenefitbecausetheyprovidedlittleinforma

    tionregardingthestructureofthesystemwewereanalyzing.Intermsof

    structuralinformation,theextradataweremostlyredundant.

    Theanalysiswascomplicatedbythefactthatthescenarioincluded

    onlytwoinstancesofthetargethandoffeventthesignalwewereto

    detect.Instructuralterms,thismeansthatwewerelookingforachange

    innetworkstructurethatinvolved(perArtisTechsdescriptionofthe

    handshake)three

    links

    at

    most.

    Thus,

    the

    statistical

    change

    detection

    analysisusedincasestudy1wasofnouse.Suchasmallchangeinstruc

    turewouldnotbedetectedasbeingstatisticallysignificant.

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    28 CARLEY,MARTIN,ANDHANCOCK

    Theanalysiswasfurthercomplicatedbytheabsenceofgeocoordi

    natesforthemobilerobots.Therefore,*ORAsgeospatialvisualization

    capabilitiescouldnotbeemployed.Theinsightthatcanbegleanedfrom

    visualizationsofagentsxlocations,asusedincasestudy1,wasalsolost.

    Withoutlocation,

    we

    also

    lacked

    any

    means

    for

    constructing

    trails

    data

    toexaminewhowaswherewhen.

    Finally,thegoalofanalysisincasestudy2differedfromcasestudy1.

    Incasestudy1,weemployedDNAtechniquesdesignedtoidentify

    importantentities,locations,andtimes.Thepurposeoftheanalysis,

    therefore,wastoidentifycentralities.Incontrast,thepurposeofthe

    analysisforcasestudy2wastoidentifyexclusivities(i.e.,thetwoTasker

    GlobalTaskerhandshakes).

    Giventhe

    impoverished

    data

    set

    and

    our

    goal

    of

    detecting

    only

    two

    instancesofthehandoffamongasmallsetofagentsandrobots,the

    analysisstrategyweadoptedforthiscasewasoneofconvergingopera

    tions(tokickstartaDNAofricherdatainthefuture).ArtisTechper

    sonnel(withtheirknowledgeofthesystem)manuallyanalyzedthedata.

    CASOSpersonnelappliedDNAtechniquestothedata.Thefollowingdis

    cussesonlytwooftheissuesweaddressed.

    TofindthehandoffwhereoneTaskingAgentloanedarobotto

    anotherTaskingAgent,wereliedonArtisTechsidentificationofmes

    sagetypesthatindicatesuchahandoffoccurred.Threemessagetypes

    wererelatedtothehandoff:RemoveIdentity,ReportPositionToSelected

    Tasker,andReportPositionToSelectedTaskerReturn.Findingthehandoff

    wasthensimplyamatterofusing*ORAsSphereofInfluencecapabilities

    tovisualizewhichagentswereinvolved.Figure1.13showsthethree

    importantmessages,alongwiththeagentsthatsentandreceivedthem.

    ItcanbeseenthatTaskingAgent3ispositionedinthenetworkdiffer

    entlythanTaskingAgents1,2,and4.Furthermore,weseethatTasking

    Agent3was

    the

    only

    agent

    to

    send

    the

    ReportPositionToSelectedTasker

    Returnmessage(asindicatedbythearrowonthelinkbetweentheagent

    nodeandthemessagenode).GlobalTaskingAgent7receivedthismes

    sageandsentaRemoveIdentitymessagetoTaskingAgent3.Thesphere

    ofinfluencealsoindicatesthattheReportPositionToSelectedTaskermes

    sagewasprobablynotuniquelyrelatedtothehandshake.

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    DynamicNetworkAnalysis 29

    Figure1.13SphereofInfluencevisualizationshowingrobothandoff

    Inanticipationofricherdatasets,thesecondissueweexaminedwas

    whetherwecoulduseDNAtechniquestopartitionagentsintofore

    groundandbackgroundagents.Tothisend,theArtisTechteamproduced

    ameticulous

    message

    trace

    analysis

    and

    event

    identification

    as

    ground

    truthfortheCASOSteam.Evenasfullyknowledgeabledesignersofthe

    communicationlogicthisanalysisanddocumentationtookmorethan4

    hoursusingsimpletextsearchandanumericmessagefrequencyanalysis

    providedbyCASOS.Thecomplexityofthisanalysisunderscorestheneed

    fornetworkanalysistechniquesforamorecompletesystemexperiment

    analysis.

    PerArtisTechsanalysis,agentscouldbedividedintoforeground

    agentsthatweresubstantivelyrelatedtothescenarioandbackground

    agentsthatexistedsimplytomakethesimulationrun.Ourtaskat

    CASOS,therefore,wastoemployoneoranotherDNAtechniquetosepa

    rateforegroundfrombackgroundagents.WefoundthattheNewman

    groupingalgorithmworkedwell,separatingforegroundandbackground

    agentsintogroupsthatcloselyapproximatedthemanualanalysis.Seven

    oftenbackgroundagentswerecorrectlyclassified.Buttherewasdis

    agreementbetweenArtisTechjudgesregardingwhetheroneofthethree

    misclassifiedagentswasabackgroundoraforegroundagent.Onefore

    groundagent

    out

    of

    29

    undisputed

    foreground

    agents

    was

    misclassified.

    ThattheNewmangroupingalgorithmcorrespondsfairlywellwiththe

    judgmentsofdomainexpertsispromising,andsuggestsalineof

    researchconcerningthepsychologicalvalidityofNewmangrouping.

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    30 CARLEY,MARTIN,ANDHANCOCK

    SYSTEMUNDERSTANDINGANDTUNINGACTIVITIESArtisTechpostulatedtheadditionalbenefitofperformingDNAon

    theoutputlogsfromtheinternalsystemcommunications;theanalysis

    supportedunderstanding

    of

    how

    the

    team

    and

    system

    achieved

    the

    mea

    suredperformance.TheARTEMISresearchteamwasintheprocessof

    settingupsystemmodelexperimentstostudytheadvantagesthatauto

    matedreasoningcouldaddtowidelyusednumericimageandvideopro

    cessingforthepurposeofPCVS.Aswemodeledthereasoningandsetit

    intothesimulationwehaveconductedmanytestruns.Wecaneasilysee

    whenthemacrosystembehaviorisasdesignedandwhenitdeviates

    fromintentions.However,todeterminewhythedeviationsoccurand

    howthe

    reactive

    agent

    networks

    achieve

    intended

    system

    performance

    requiresmessagelevelanalysis.ArtisTechsharedmixedresulttestlogs

    withCASOSspecificallytofacilitatetheidentificationofexpectedand

    unexpectedresults,andhowtheyarise.

    Resultsfrominitialanalysesinbothcasestudiesdivergedfrom

    expectedresults.Inhindsightthisishardlysurprising.Designofacom

    plex,multiagentsystemwithemergentreactivesystembehaviormay

    notbepossiblewithoutthesupportofnetworkanalytics.

    Inbothcaseswefoundevidenceofpragmatic,technicallycorrect,

    programmingpracticesthatinterferedwithsubstantiveDNAofthecommunicationslogs.ArtisTechconfirmedthattheexperimentrunsthat

    wereanalyzedwerenotconsideredfinalorexpectedtobeentirelycor

    rect,merelytypicalincontentandform.Whetherweviewthisasaveri

    ficationissue(i.e.,buildingthethingright)oravalidationissue(i.e.,

    buildingtherightthing)dependsonperspective.Giventhatverification

    isprimarilyaninternalactivity;thedegreetowhichprogrammers

    achievedtheintentbehindspecificationsisamatterofinterpretation.

    Fromthe

    perspective

    of

    network

    analysis

    (i.e.,

    users

    of

    the

    output

    logs),

    however,wecannoteaminorshortfallinvalidation.Specifically,com

    municationrecordsthatarenotrelevanttothescenariobeinganalyzed

    shouldbefilteredfromthelogtoincreaseusability.

    Intheinitialanalysis,weexperimentallyillustratedthatDNA

    approachesprovideacapabilitytoanalyzecomplexmessagesetstofind

    particularbehaviorpatternsofinterest.Inthesecondanalysiswebegan

    forgingacollaborativeresearchapproachdesignedtounearththeana

    lyticsteps

    the

    combinations

    of

    DNA

    techniques

    required

    to

    analyze

    differenttypesofmessagingbehavior.

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    DynamicNetworkAnalysis 31LESSONSLEARNEDANDFUTUREDIRECTIONS

    Opencollaborationbetweendataprovidersandnetworkanalysts

    createdabeneficialgapbetweenexpectedandobservedsystembehav

    ior.As

    data

    provider,

    ArtisTech

    developed

    the

    multi

    agent

    system

    and

    environmentsimulations,designedthescenarios,andconductedthe

    simulationbasedexperimentswithexpectedsystembehaviorsinmind.

    Thenonlinearitiesinherenttocomplexsystemscomprisedofinteracting

    agents,however,makeitnotoriouslydifficulttopredictemergentand

    reactivebehavior,andareindeedthereasoncomputersimulationisnec

    essary.Asnetworkanalyst,CASOSreceivedmilitarilyrelevantbattlefield

    simulationdatawithoutpriorknowledgeofexpectedsystembehavior.

    Thechallenge

    to

    CASOS,

    therefore,

    was

    to

    use

    DNA

    to

    characterize

    what

    happenedinthemysteriousscenariosreceivedandCASOSobserva

    tionsinitiallydivergedfromArtisTechdefaultexpectations.Toresolvethe

    discrepancy,weusedDNAtoexaminewhythesimulationsdidnot

    behaveasexpected.Thus,thepostulatedbenefitoftheArtisTechCASOS

    collaborationwastheuseofnetworkanalyticstogaininsightintothe

    performanceofmultiagentsystems.ArtisTech,withCASOS,nowplans

    tousethisapproachandDNAtoolstobuildasetofreusablesystem

    experimentanalysismethodsthatwillbeappliedtounderstandhow

    variantHuman/AutomationPCVSexperimentsachieveobservedresultsusingnetworksofcommunicationandbehaviors.

    WithregardtodemonstratingthetacticalrelevanceofDNA,the

    availabilityofmilitaryscenariodataisinvaluable.Itprovidesopportuni

    tiestocombineextantDNAtechniquesintoanalyticstrategiesthatpro

    duceresultswarfighterscanuse.Generally,wefoundthatthefamilyof

    DNAmetricsandvisualizationsthathavebeenimplementedin*ORA

    overthepast10orsoyearsprovidesanamplebasisforconductingtacti

    callyrelevant,

    actionable

    analyses

    on

    battlefield

    data.

    Two*ORAcapabilitieswereparticularlyhelpfulduringthiseffort:

    geovisualizationandnetworkchangedetection.The(notsosimple)act

    ofplacingnetworksonamapputsabstractsocialnetworksintoacon

    crete,spatialcontext.Itprovidesexplicitinformationaboutwherethe

    actionistakingplace.Thecapacitytodetectstructuralchangesamong

    temporallyorderednetworksprovidesexplicitinformationaboutwhen

    theactionistakingplace.

    Thecase

    studies

    also

    helped

    to

    identify

    several

    areas

    where

    future

    developmentcouldimprove*ORAstacticalrelevance.Theimprove

    mentswouldgenerallysupportdeliveryofoneormoreTacticalInsight

    Reports.Asenvisioned,thesereportswouldcontaintheoutputsofall

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    32 CARLEY,MARTIN,ANDHANCOCK

    DNAtechniquesthatcontributetoaparticularanalyticstrategy.From

    thetwocasestudiesdescribedabove,itappearsthatcorrespondences

    amongnetworksoftherelationsamongentities,networksofgeospa

    tiallyanchoredentities,andnetworksdistributedovertimewillplaya

    centralrole

    in

    such

    reports.

    ForArtisTechthegoalofDNAapplicationstosystemanalysisand

    monitoringistoinvestigatethecreationofageneralizeddatastructure

    andDNAmethodcombinationapproachthatwillallowtheencodingof

    expectedordetectedmessageandbehaviorpatterns.Theinitialapplica

    tionofthisconcernspostexperimentreview.Themorefarreaching

    implicationsofsuchDNAmechanismsextendtorealtimeembedded

    systemmonitoringtoincreasedistributedsystemsecurityandusertrust.

    ACKNOWLEDGEMENTS

    ThisworkispartoftheDynamicsNetworksprojectatthecenterfor

    ComputationalAnalysisofSocialandOrganizationalSystems(CASOS)of

    theSchoolofComputerScience(SCS)atCarnegieMellonUniversity

    (CMU).For*ORA,forthepartsusedinthisanalysis,thegeospatialcom

    ponentsweresupportedbyAROandERDCTECW911NF0710317,the

    *ORALoombyONRN000140610104,theovertimechangedetection

    basicanalysisbyARIW91WAW07C0063andtheORAimplementationofchangedetectionbyARLDAAD190120009,thefourieranalysisbyONR

    N000140610104,thekeyentityanalysiswassupportedbyONR

    N000140610104,extensionstohandlecommunicationsnetworksby

    ARLthroughthe CommunicationsandNetworks(CN)Collaborative

    TechnologyAlliance(CTA)20002504andtheimmediateimpactassess

    mentbyONRN000140610104.Thebasicresearchconductedhereto

    explorehowtousethesetechnologiesforadversarialbehaviorandto

    linkto

    the

    ArtisTech

    ARTEMIS

    PCVS

    system,

    AlgoLink

    simulator,

    DARE

    wassupportedbytheArmyResearchLabthroughtheAdvancedDecision

    Architecture(ADA)CollaborativeTechnologyAlliance(CTA) DAAD1901

    20009.Theviewsandproposalscontainedinthisdocumentarethoseof

    theauthorandshouldnotbeinterpretedasrepresentingtheofficialpol

    icies,eitherexpressedorimplied,oftheOfficeofNavalResearch,the

    ArmyResearchOffice,theArmyResearchInstitute,theArmyResearch

    LabortheU.S.government.

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    DynamicNetworkAnalysis 33REFERENCES

    Carley,K.M.(2002).Smartagentsandorganizationsofthefuture.InL.Lievrouw&

    S.Livingstone(Eds.),Thehandbookofnewmedia(pp.206220).ThousandOaks,CA:Sage.Carley,K.M.,Columbus,D.,DeReno,M.,Reminga,J.,&Moon,I.C.(2008).ORAUsersGuide2008(Tech.Rep.No.CMUISR08125).Pittsburgh,PA:InstituteforSoftwareResearch,SchoolofComputerScience,CarnegieMellonUniversity.

    Davis,G.B.,&Carley,K.M.(2008).ClearingtheFOG:Fuzzy,overlappinggroupsfor

    socialnetworks.SocialNetworks,30(3),201 212.Davis,G.B.,Olson,J.,&Carley,K.M.(2008).OraGISandloom:Spatialandtemporal

    extensionstotheORAanalysisplatform(Tech.Rep.No.CMUISR08121).Pittsburgh,PA:InstituteforSoftwareResearch,SchoolofComputerScience,CarnegieMellon

    University.

    McCulloh,I.,

    &

    Carley,

    K.M.

    (2008).

    Detectingchangeinhumansocialbehaviorsimulation(Tech.Rep.No.CMUISR08135).Pittsburgh,PA:InstituteforSoftware

    Research,SchoolofComputerScience,CarnegieMellonUniversity.

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    34 CARLEY,MARTIN,ANDHANCOCK

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    E D I T E D B Y PAT RI C I A M C D E RM O T T AN D LAU RE L ALLE N D E R

    ADVANCED DECISI ON ARCHITEC TURES

    FOR THE WARFI GHTE R:F O U N D AT I O N S A N D T E C H N O L O G Y

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    i

    A D VA N C E D D E C I S I O N A R C H I T E C T U R E S

    F O R T H E WA R F I G H T E R :

    F O U N D AT I O N S A N D T E C H N O L O G Y

    E D I T E D B Y PAT R I C I A M C D E R M O T T

    A N D L A U R E L A L L E N D E R

    This book, produced by the Partners of the

    Army Research Laboratory Advanced Decision Architectures

    Collaborative Technology Alliance, also serves as the

    Final Report for DAAD19-01-2-0009.

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    SECTIONI.COLLECTING,

    PROCESSING,

    AND

    DISTRIBUTING

    BATTLEFIELD

    INFORMATION

    SECTIONI

    COLLECTING,PROCESSING,ANDDISTRIBUTINGBATTLEFIELD

    INFORMATION

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    14 SECTIONI

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    35

    Chapter2

    2.

    FROMBACKGROUNDSUBTRACTIONTOTHREATDETECTIONIN

    AUTOMATEDVIDEOSURVEILLANCE

    JoshuaEckroth

    TheOhio

    State

    University,

    Columbus,

    OH

    DikpalReddy

    UniversityofMaryland,UMIACS,CollegePark,MD

    JohnR.Josephson,Ph.D.

    TheOhioStateUniversity,Columbus,OH

    RamaChellappa,

    Ph.D.

    UniversityofMaryland,UMIACS,CollegePark,MD

    TimothyN.Miller

    TheOhioStateUniversity,Columbus,OH

    INTRODUCTION:PERSISTENTVIDEOSURVEILLANCEAsvideocamerasandothersensorsbecomecheaperandeasierto

    network,sensornetworksbecomeincreasinglyattractivemeansto

    acquireusefulinformationformilitaryoperations,suchasvideosurveil

    lanceforfacilitiesprotection,andpersistentsurveillancetomaintain

    sensorycontactwithtargetsofinterest(Pendal,2005).However,without

    assistancefromautomation,humanswillbeoverloadedbyinformation,

    andunabletouseiteffectively.

    Whatinformationconsumesisratherobvious:itconsumesthe

    attentionof

    its

    recipients.

    Hence

    awealth

    of

    information

    creates

    apov

    ertyofattention,andaneedtoallocatethatattentionefficientlyamong

    theoverabundanceofinformationsourcesthatmightconsumeit.

    (Simon,1971)

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    36 ECKROTHETAL.

    Itisdifficultforhumanstovigilantlymonitoralargenumberofvideo

    feedsforextendedperiodswithoutfatigue,orcomplacency,especiallyif

    theyareaskedtorecognizethesignificanceofrareeventsinacomplex

    streamofevents(Warm,et.al.,1996;Grier,et.al.2003;Pattyn,et.al.,

    2008).Moreover,

    sometimes

    events

    of

    interest

    cannot

    be

    recognized

    simplyfromthevideowithoutknowingwhereaspecificcameraispoint

    ing,atarestrictedarea,forexample.Keepingtrackofthelocationand

    significanceofacamerasfieldofviewimposesanadditionalcognitive

    burden.Thecognitiveburdenisevengreaterifrecognizingeventsof

    interestrequirestrackingentitiesastheybecomevisibleindifferentcam

    eras,andaccessingmentalmapstounderstandthesignificanceof

    motionpaths.

    Automationcan

    help.

    It

    can

    potentially

    provide

    users

    with

    alerts

    basedonrecognizingindicatorsofthreateningbehavior,includingbehav

    iorthatcannotbedetectedwithasinglecamera.Forexample,themove

    mentofanentityfromplacetoplaceinrelationtothemapmightshowa

    patternindicativeofscoutingtheperimeterofafacility,wherenosingle

    cameraviewshowsanythingsuspicious.Manyunsolvedtechnicalprob

    lemsremain,however,includingproblemsabouthowtoextractneeded

    informationfromvideoimagery,andproblemsofhowtoprocess

    acquiredinformationtoclimbthelevelsofabstractionfromindividual

    cameracenteredframeworkstoaworldcenteredframework,andfrom

    motiondescription(ObjectO5604movedalongpathP52fromlocation

    L12attimeT55toL13atT66.)tobehaviordescription(O5604proceeded

    slowlynorthonroadR3 totheintersectionwithR7,turnedEastonR7.)torecognitionofindicatorsofthreat(O5604slowlycircledthefacil

    ity.).

    Abundantvideoalsothreatenstooverloadcommunicationsand

    storagesystems.

    Typically,

    the

    sensed

    bits

    are

    highly

    redundant

    for

    the

    tasktobeperformed.Forexample,whenitisimportanttotrackamov

    ingobject,theimportantinformationiswhichpartoftheimageischang

    ingcontinuously.Tounderstandwhichregionisrelevant,subtractionof

    theunchangingbackgroundisneeded,andifitcanbeperformedatthe

    sensoritself,significantlyfewerbitsneedtobetransmitted.Accordingly,

    anewframeworkcanbeenvisagedinwhichthetraditionalwaysofsens

    inganimage(inrectangularpixels)arereplacedbysensingtheimage

    information

    in

    a

    compact

    form

    (compressed

    sensing),

    and

    then

    recon

    structingtherequiredimage,asneeded,fromthiscompactinformation.

    Thispaperdescribessomeelementsofrecentprogressintechnology

    forvideosurveillancethatspecificallyaddressmethodsforbackground

    subtractiontodetectchangesfromframetoframeinvideo,trackingof

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    AutomatedVideoSurveillance 37

    viewedobjectsincameracenteredimagespace,trackingofobjectsin

    worldorientedobjectspaceusinginformationfrommultiplecameras,

    andmethodsforclimbinglevelsofabstractionindescriptionsof

    behavior.

    BACKGROUNDSUBTRACTIONANDTRACKINGUSINGCOMPRESSIVECAMERAS

    Introduction

    Mostcamerasinstalledforsurveillanceapplicationsareusedforsim

    plevisiontaskssuchasdetectionandtracking,poseestimation,and3D

    reconstruction

    from

    silhouettes,

    and

    very

    few

    for

    higher

    level

    tasks

    such

    asactivityrecognition.Inmanyofthesetasks,theamountofdatacol

    lectedishugeforthepurposeoftheapplication.Forexample,atypical

    backgroundsubtractionalgorithmcomparesasingleframe,fullresolu

    tionimageobtainedfromacameratoanotherfullresolutionimagethat

    hasbeenlabeledthebackground.Pixelsthatdifferbetweenthetwo

    imagesareconsideredforeground.Theresultisblobsinthefore

    groundthatrepresentobjectsthatarebelievedtohavemovedbetween

    thetimethebackgroundimagewasacquiredandthetimethefore

    groundimage

    was

    acquired

    (usually,

    the

    background

    image

    is

    updated

    everytimeanewframeisobtainedfromthecamera,sothatmovements

    fromoneframetothenextaredetectedandplacedintheforeground).

    Theresultingforegroundimageisoftenrepresentedasablackandwhite

    fullresolutionimage,whereblackrepresentsbackgroundandwhiterep

    resentsforeground;iftheseimagesareobtainedfrom,say,parkinglot

    surveillance,thentheforegroundblobswilllikelyresemblesilhouettes

    ofmovingcarsandwalkingpeople.Yet,theseblobsoccupyonlysmall

    regionsof

    the

    image,

    since,

    in

    most

    surveillance

    video,

    there

    are

    few

    movingobjectsatanyonetime.Similarly,whentracking,weareinter

    estedinonlyasmallregionoftheimagethatismoving,anddonotcare

    abouttheotherpartsoftheimage.Neverthelesstheentireimageis

    commonlysensedandtransmittedtoacentrallocationforprocessing.

    Thismeansthatahugeamountofdata,whichisultimatelyuseless,is

    collectedandtransmitted,thuswastingsensingandbandwidth

    resources.Inthispaper,wepresentanapproachtoalleviatingthisprob

    lem.We

    show

    our

    approach

    on

    two

    vision

    applications:

    background

    sub

    tractionandtracking.Inbothoftheseapplications,weusea

    compressivecameratoobservetheimagesandthenprocessingis

    doneonthesemeasurements.

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    38 ECKROTHETAL.

    Acompressivecameraisadevicethathasbeenbuiltontheprinci

    plesofcompressedsensing(Candes,2006).Suchacamerameasures,not

    theimagepixelslikeaconventionalcamera,butasmallnumberofran

    domlinearprojectionsoftheimage.Thenumberofrequiredmeasure

    mentsis

    significantly

    fewer

    than

    the

    number

    of

    pixels

    in

    aconventional

    camera,andthisinherentlyreducesthespaceneededtostorethe

    image.Thefullimage(intheformofpixels)canbereconstructedfrom

    theselinearcombinations.

    Wepresentaninnovativeapproachwhereinvisiontasksareper

    formed,notonthefullimages,butonthecompressedmeasurements

    directly,withouttheneedtoreconstructthefullimages.Becausethefull

    imageisnotneededforthetasks,asignificantreductionisachievedin

    theamount

    of

    data

    that

    needs

    to

    be

    sensed.

    In

    the

    next

    section,

    we

    pro

    videabriefintroductiontocompressedsensingtheoryandcompressive

    cameras.Wethenpresentourapproachtobackgroundsubtractionand

    trackingoncompressedmeasurements.

    CompressiveCamerasandComputerVisionApplicationsCompressedSensing.Supposewehaveanimage ofsize

    (i.e.,vectorized),

    then

    we

    can

    represent

    the

    image

    in

    some

    basis

    as

    (1)

    where isasparsecoefficientvector( sparse).Thevector has

    veryfewlargenonzerocomponentsindicatingthattheimagecanbe

    compressed.Waveletsareanexampleofsuchabasis.

    IntheCSframework(Candes,2006)wedonotmeasurethe larg

    estelementsof ,butweinsteadmeasure linearprojectionsof

    theimage ontoanotherbasis .

    (2)

    where arethecompressedmeasurements.Since ,the

    systemofequationsareunderdetermined,bututilizingthesparsityofwecanrecoverthesignalbysolvingthefollowing optimization

    problemcalledBasisPursuit.

    (3)

    Compressivecameras.Basedoncompressivesensing(CS)theory,a

    prototypesinglepixelcamera(SPC)wasproposedin(Wakin,2006).The

    x 1N

    x =

    M N