简介:TheeffectofstressdistributionduetothechangesofthedistalscrewalignmentinrelationtotheGammanailandthefemoralshaftisthoroughlystudiedinthispaper.FailureoftheGammanailcompositeoccursthroughthecranialapertureofthedistalscrewsandtheinsertionholeforthelagscrewduetononunion,delayed-unionandcontinuedweight-bearing.Athree-dimensionalfiniteelementmodelwasusedtostudythefracturedfemur,theGammanail,thelagscrewandthedistallockingscrews.ThefirstandtheseconddistalscrewswereinsertedintotheGammanailinfourdifferentconfigurations.WefoundthatthestressoftheGammanailcompositewassubstantiallyreducedwiththetwoscrewsconfiguredintheanteriortoposteriordirection.Thisalignmentcanbeargreaterloadinginthemoredemandingfracturetypes.Inthesubtrochantericfractureorthecomminutedfracturesattheproximalfemur,theoptimalalignmentofthetwodistalscrewswasintheanteriortoposteriordirection.
简介:TheserviceprovidedbytheGC(GammaCameras)intheNuclearMedicinedepartmentsfailsbecauseoftheirbreakdown,generallyduetotheassociatedelectronicsandnottothephysicaldetectioncomponents.Forthisreason,itwasdecidedtodevelopanelectronicsystemthatallowstherecoveryandoptimizationofdisusedGC,startingwiththedesignofthepreamplifierforaPMT(photomultipliertube).Thecircuitwasdesignedandsimulatedandthelistofcomponentsnecessaryfortheconstructionofthepreamplifierwasgenerated,aswellastheprintedcircuitboardwasdesignedforitsassembly.Bysimulatingthepreamplifierthisworkedinlinearmode.Thisdeterminesthattheamplitudeoftheoutputsignalisproportionaltotheamountofchargedeliveredbythedetector.ThiscardallowsanautomaticadjustmentofthesignalsofthePMTasdothemodernGC.
简介:Inthispaper,wedevotetoconstructingtheone-sidedempiricalBayes(EB)testforthelocationparameterintheGammadistributionbynonparametricmethod.Undersomemildconditions,weprovethattheEBtestisasymptoticallyoptimalwiththerateoftheorderO(n-δs/2s+1),where1/2≦δ<1ands>1isagivennaturalnumber.Anexampleisalsogiventoillustratethattheconditionsofthemaintheoremsareeasilysatisfied.
简介:Synchronousgammaoscillationsarebelievedtoplayaprominentroleintheinformationprocessingofbiologicalneuralsystems.Experimentalobservationshavefoundthatthefrequencyandpowerofgammaoscillationsintheprimaryvisualcortex(V1zone)areregulatedbytheilluminationcontrastofvisualstimulus.However,theunderlyingmechanismofhowthesynchronousoscillationsdependontheilluminationcontrasthasnotbeenwellexplained.Weproposealocalexcitatory/inhibitory(E/I)neuronalnetworkofintegrate-and-fire(IAF)neuronswiththedifference-of-Gaussians(DOG)receptivefieldtounveilthismechanism.Simulationresultsdemonstratethatthehighertheilluminationcontrast,thehigherthefrequencyofgammaoscillations.Thepowerofgammaoscillationsalsoincreaseswiththeincreaseofilluminationcontrast.Theseresultsareconsistentwiththeexperimentalfindings.
简介:P2Psystemsarecategorizedintotree-basedandmesh-basedsystemsaccordingtotheirtopologies.Mesh-basedsystemsareconsideredmoresuitableforlarge-scaleInternetapplications,butrequireoptimizationonlatencyissue.Thispaperproposesacontentsubscribingmechanism(CSM)toeliminateunnecessarytimedelaysduringdatarelaying.Anodecansendcontentdatatoitsneighborsassoonasitreceivesthedatasegment.Noadditionaltimeistakenduringtheinteractivestagespriortodatasegmenttransmissionofstreamingcontent.CSMconsistsofthreesteps.First,everynoderecordsitshistoricalsegmentslatency,andadoptsgammadistribution,whichpossessespowerfulexpressionability,toexpresslatencystatistics.Second,anodepredictssubscribingsuccessratioofeveryneighborbycomparingthegammadistributionparametersofthenodeanditsneighborsbeforeselectinganeighbornodetosubscribeadatasegment.Theabovestepswouldnotincreaselatencyastheyareexecutedbeforethedatasegmentsarereadyattheneighbornodes.Finally,thenode,whichwassubscribedto,sendsthesubscribeddatasegmenttothesubscriberimmediatelywhenithasthedatasegment.ExperimentsshowthatCSMsignificantlyreducesthecontentdatatransmissionlatency.
简介:Recently,intenseresearchintolaserplasmaacceleratorshasachievedgreatprogressintheproductionofhigh-energy,high-qualityelectronbeamswithGeV-levelenergiesinacm-scaleplasma.Theseelectronbeamsopenthedoorforbroadapplicationsinfundamental,medical,andindustrialsciences.Herewepresentconceptualdesignsofanextremeultravioletradiationsourcefornext-generationlithographyandalaserComptonGamma-beamsourcefornuclearphysicsresearchonatable-topscale.
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