Two different clay levels at mean depths of about 2 and 4 m depth have been imaged.docx
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Twodifferentclaylevelsatmeandepthsofabout2and4mdepthhavebeenimaged
Titan'ssurfaceat2.2-cmwavelengthimagedbytheCassiniRADARradiometer:
Calibrationandfirstresults OriginalResearchArticle
Icarus,Volume200,Issue1,March2009,Pages222-239
M.A.Janssen,R.D.Lorenz,R.West,F.Paganelli,R.M.Lopes,R.L.Kirk,C.Elachi,S.D.Wall,W.T.K.Johnson,Y.Anderson,R.A.Boehmer,P.Callahan,Y.Gim,G.A.Hamilton,K.D.Kelleher,L.Roth,B.Stiles,A.LeGallandtheCassiniRadarTeam
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Abstract
ThefirstcomprehensivecalibrationandmappingofthethermalmicrowaveemissionfromTitan'ssurfaceisreportedbasedonradiometricdataobtainedat2.2-cmwavelengthbythepassiveradiometerincludedintheCassiniRadarinstrument.Thedatareportedwereaccumulatedfrom69separateobservationalsegmentsinTitanpassesfromTa(October2004)throughT30(May2007)andincludeemissionfrom94%ofTitan'ssurface.Theyarediverseinthekeyobservingparametersofemissionangle,polarization,andspatialresolution,andtheirreductionintocalibratedglobalmosaicmapsinvolvedseveralsteps.Analysisofthepolarimetryobtainedatlowtomoderateresolution(50+km)enabledintegrationoftheradiometryintoasinglemosaicoftheequivalentbrightnesstemperatureatnormalincidencewitharelativeprecisionofabout1K.TheHuygensprobemeasurementofTitan'ssurfacetemperatureandradiometryobtainedonTitan'sdunefieldsallowedustoinferanabsolutecalibrationestimatedtobeaccuratetoalevelapproaching1K.Theresultsprovideevidenceforasurfacethatiscomplexandvariedonlargescales.Theradiometryprimarilyconstrainsphysicalpropertiesofthesurface,whereweseestrongevidenceforsubsurface(volume)scatteringasadominantmechanismthatdeterminestheemissivity,withthepossibilityofafluffyorgraded-densitysurfacelayerinmanyregions.Theresultsareconsistentwith,butnotnecessarilydefinitiveofasurfacecompositionresultingfromtheslowdepositionandprocessingoforganiccompoundsfromtheatmosphere.
ArticleOutline
1.Introduction
2.TheCassiniradiometer
2.1.Description
2.2.Calibration
2.2.1.Beamcalibration
2.2.2.Relativegaincalibration
3.Observationsandinitialcalibration
4.MappingTitan
4.1.Summary
4.2.Emissionmodel
4.3.Dielectricmosaic
4.4.Brightnesstemperaturemosaic
4.5.Mosaicuncertainties
4.6.Absolutecalibration
5.Discussion
6.Conclusions
Acknowledgements
References
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Analysisofunderwatermammalvocalisationsusingtime–frequency-phasetracker OriginalResearchArticle
AppliedAcoustics,Volume71,Issue11,November2010,Pages1070-1080
CornelIoana,CédricGervaise,YannStéphan,JerômeI.Mars
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Abstract
Oneofthemostchallengingapplicationsoftime–frequencyrepresentationsdealswiththeanalysisofthesignalissuedfromnaturalenvironment.Recently,theinterestforpassiveunderwatercontextincreased,basicallyduetotherichinformationcarriedoutbythenaturalsignals.Takenintoaccountthenon-linearmulti-componenttime–frequencybehaviourofsuchsignals,theiranalysisisachallengingproblem.
Inthiscontext,theanalysisofunderwatermammal’swhistlesisaimedtoextract,accuratelyandadaptively,theirmaintime–frequencycomponents.Inthispaper,wedefineatime–frequency-phasetrackerwhichiscomposedofthreesteps.Thefirstoneconsistsofmodellingtheshort-timesegmentsofthevocalizationbyasetofthirdorderpolynomialphasemodulations.Thesecondstepconsistsinthefusionoflocalpolynomialphasemodulationsaccordingtoalocalphasecontinuitycriterion.Finally,inthethirdstep,thedetectedtime–frequencytrackisusedtodesignthetime–frequencyfilter,inchargeofextractingthesamplescorrespondingtothedetectedtrack.Thisprocedureistheniterateduntilallcomponentofinterestareextracted.
TestsprovidedforrealisticscenariosandrealdatatakeninBayofBiscayatSeptember2009containingwhistlesofcommondolphinDelphinusdelphisillustratethepotentialandthebenefitsoftheproposedapproach.
ArticleOutline
1.Introduction
2.Time–frequency-phasetracker
2.1.Step1:
shorttimeanalysis
2.2.Step2:
selectionandfusion
2.3.Step3:
componentextraction
3.Resultsonrealdata
4.Conclusion
Acknowledgements
References
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Optimizationofpressbendformingpathofaircraftintegralpanel OriginalResearchArticle
TransactionsofNonferrousMetalsSocietyofChina,Volume20,Issue2,February2010,Pages294-301
YuYAN,MinWAN,Hai-boWANG,LinHUANG
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Inordertodesignthepressbendformingpathofaircraftintegralpanels,anoveloptimizationmethodwasproposed,whichintegratesFEMequivalentmodelbasedonpreviousstudy,theartificialneuralnetworkresponsesurface,andthegeneticalgorithm.First,amulti-steppressbendformingFEMequivalentmodelwasestablished,withwhichtheFEMexperimentsdesignedwithTaguchimethodwereperformed.Then,theBPneuralnetworkresponsesurfacewasdevelopedwiththesampledatafromtheFEMexperiments.Furthermore,geneticalgorithmwasappliedwiththeneuralnetworkresponsesurfaceastheobjectivefunction.Finally,verificationwascarriedoutonasimplecurvaturegrid-typestiffenedpanel.Theformingerrorofthepanelformedwiththeoptimalpathisonly0.09839andthecalculatingefficiencyhasbeenimprovedby77%.Therefore,thisnoveloptimizationmethodisquiteefficientandindispensableforthepressbendformingpathdesigning.
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Erratumto“Failureanalysisofbrazedairpassagesofanaircraftfuelsystem[EngineeringFailureAnalysis,Volume17,Issue6,September2010,Pages1495–1499]”
EngineeringFailureAnalysis,Volume18,Issue1,January2011,Page531
A.R.Etemadi,P.Behjati,H.R.MadaahHosseini,A.H.Kokabi
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Abstract
Airpassagesofanaircraftfuelsystemaremanufacturedfrom4130steeltubesbrazedusingBNi-4fillermetal.Itwasobservedthatbrazedtubesleakafterflyingabout100 h.Inthiscasestudy,microscopytechniquesandhardnessmeasurementswereemployedtoidentifytherootcauseofthisfailure.Itwasfoundthatwidejointclearancepromotesbrittlephasesatthejointcenterlinewhichcanactascracknucleationsitesunderthermalexpansionandmisalignmentstresses.Basedontheobtainedresults,jointclearancewasreducedtooptimumvalue.Thisreductionprohibitedtheoccurrenceofleakageandsolvedtheproblem.
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Decorrelatingwirelesssensornetworktraffictoinhibittrafficanalysisattacks OriginalResearchArticle
PervasiveandMobileComputing,Volume2,Issue2,April2006,Pages159-186
JingDeng,RichardHan,ShivakantMishra
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Abstract
Typicalpackettrafficinasensornetworkrevealspronouncedpatternsthatallowanadversaryanalyzingpackettraffictodeducethelocationofabasestation.Oncediscovered,thebasestationcanbedestroyed,renderingtheentiresensornetworkinoperative,sinceabasestationisacentralpointofdatacollectionandhencefailure.Thispaperinvestigatesasuiteofdecorrelationcountermeasuresaimedatdisguisingthelocationofabasestationagainsttrafficanalysisattacks.Asetofbasiccountermeasuresisdescribed,includinghop-by-hopreencryptionofthepackettochangeitsappearance,impositionofauniformpacketsendingrate,andremovalofcorrelationbetweenapacket’sreceipttimeanditsforwardingtime.Moresophisticatedcountermeasuresaredescribedthatintroducerandomnessintothepathtakenbyapacket.Packetsmayalsoforkintomultiplefakepathstofurtherconfuseanadversary.Atechniqueisintroducedtocreatemultiplerandomareasofhighcommunicationactivitycalledhotspotstodeceiveanadversaryastothetruelocationofthebasestation.Theeffectivenessofthesecountermeasuresagainsttrafficanalysisattacksisdemonstratedanalyticallyandviasimulationusingthreeevaluationcriteria:
totalentropyofthenetwork,totaloverhead/energyconsumed,andtheabilitytofrustrateheuristic-basedsearchtechniquestolocateabasestation.
ArticleOutline
1.Introduction
2.Networktrafficandthreatmodel
3.Basicdecorrelationcountermeasures
3.1.Hiddenpacketdestinationaddress
3.2.Decorrelatingpacketsendingtimes
3.3.Controllingpacketsendingrates
3.4.Limitations
4.Inhibitingtrafficanalysisattackswithrandomizedtraffic
4.1.Multi-parentroutingscheme
4.2.Randomwalk
4.3.Fractalpropagation
4.3.1.Fractalpropagationwithdifferentforkingprobabilities
4.3.2.Enforcedfractalpropagation
4.4.Nodecompromises
4.5.Simulationresultsandsummary
5.Evaluation
5.1.Evaluationcriteria
5.2.Messageoverheadofratecontrolmechanism
5.3.Effectivenessandcostofrandomizedtraffictechniques
5.4.Effectivenessofprandpf
6.Relatedwork
7.Futurework
8.Conclusion
Acknowledgements
References
Vitae
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