简介:Manyofusbelievethataperson'smindbecomeslessactiveashegrowsolder.Butthisisnot.true,accordingtoDr.LissyF.Jarvik,professorofpsychiatry(精神病学)attheUniversityofCalifomia,LosAngeles,andaboardmemberoftheNewCenterforAgingattheVeteransHospital.Shehasstudiedthementalfunctioningofagingpersonforseveralyears.
简介:Ashopkeeperwhosellsgoodsformorethanwhathepaidforthemmakesaprofitonthetransaction.Ontheotherhand,onewhosellsgoodsforlessthanwhathepaidforthemmakesalossonthetransaction.Theprofit(orloss)madeonatransactionisoftenexpressedasapercentageofthecostprice(ie.thepricepaidbytheshopkeeperfortheitem).
简介:TheanalysisofcelllossratesinanATMMuxwithlossprioritiesisanimportantprobleminthe-studyoftrafficcontrolinATMnetworks.Inthispaper,thelossratesofthecellswithdifferentprioritiesinanATMMuxareanalyzedbyapproximatingtheactualinputprocesswithtwo-stateMMDPandfluidflowtechnique,andtheanalyticalexpressionsoftherelationbetweenthelossratesandthebuffersizeareobtained.Simulationshowsthattheapproachissullicientlyaccurateforapplications.
简介:AtypeofsilicondetectorknownasAXUV(absoluteextremeultraviolet)photodiodesissuccessfullyusedtomeasuretheradiatedpowerinEAST.Thedetectorischaracterizedbycompactstructure,fasttemporalresponse(<0.5s)andflatspectralsensitivityintherangefromultra-violettoX-ray.Two16-channelAXUVarraysareinstalledinEASTtoviewthewholepoloidalcross-sectionofplasma.Basedonthediagnosticsystem,typicalradiationdistributionsforbothlimiteranddivertorplasmaareobtainedandcompared.Asdivertordetachmentoccurs,theradiationdistributioninX-pointregionisobservedtovarydistinctly.Thetotalradiationpowerlossesindischargeswithdifferentplasmaparametersarebrieflyanalyzed.
简介:考虑在有m的无限的供应下面的项目挑选的定价n的问题照看了买主,其各个至多对感兴趣项目的k。目标是与利润额p定价每个项目1,p2,,pn以便最大化全面利润。当每个项目上的价格一定在它的边缘费用上面时,由Balcan和Blum有一个O(k)近似算法;即,每pi>0。当卖主被允许在他们的边缘费用下面定价一些项目时,我们调查上述问题。它被Balcan等显示出。由一些下面的项目花费了的定价,卖主能可能增加最大的利润由(木头n)时间。以低价格卖刺激另外的有利出售的这些项目通常被称为损失领导人。当一些项目能在费用下面被定价时,什么样的近似保证是可完成的,是不清楚的。理解这个问题被Balcan和Blum作为一个开的问题提出。在这份报纸,我们为定价损失领导人的问题给强壮的否定结果。我们证明那假设唯一的比赛推测(UGC),为有在甚至当每个顾客至多是感兴趣的在里面时,允许的费用下面的价格的条款定价没有经常的近似算法三个项目。概念上,尽管由在他们的边缘费用下面卖一些项目赚更多的钱是可能的,我们的结果显示那,那么做能是计算地难处理的。
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简介:Purpose:Tostudythecorrelationbetweenfunctionalandstructurallossinchronicglaucoma,asdetectedbyFrequencyDoublingTechnology(FDT)andHeilderbergRetinaTomograph(HRT).MaterialandMethods:60eyesof60patientswitheitherocularhypertensionorchronicopen-angleglaucomaunderwentvisualfieldtestingwithbothstandardautomated
简介:Amethodfortheinversionofthetransmissionlossesforthebottomreflectionlossisproposedonthebasisofthetheoryofthesmooth-averagedsoundfield.Theprocedureoftheinversionisbasedonthecri-terionoftheleastsquareerrorinthetransmissionlossesbetweencalculationandmeasurement.ByusingtheGauss-Newtoniterativeapproach,thenon-linearleastsquarealoqrithmisequivalenttosolvingase-quenceoflinearedleastsquareproblems.ThephysicalcausesoftheinstabilityoftheinvertionproblemarediscussedandthestabilityisimprovedbymeansoftheLevenberg-Marquardtmethod.Bothnumericalsimulationswithnoiseandexperimentalresultsshowthattheinversionforthebottomreflectionlossofsmallgrazinganglehashighprecisionandthecertainperturbationinthemeasuredtransmissionlossesdoesnotleadtoseriousdeviationintheinversionresultofthebottomreflectionloss.
简介:Sincethe1970s,outcomestudiesforchildrenwithhearinglossexpandedfromfocusingonassessingauditoryawarenessandspeechperceptionskillstoevaluatinglanguageandspeechdevelopment.Sincetheearly2000s,themulti-centerlargescaleresearchsystematicallystudiedoutcomesintheareasofauditoryawareness,speech-perception,languagedevelopment,speechdevelopment,educationalachievements,cognitivedevelopment,andpsychosocialdevelopment.Thesestudiesadvocatedtheestablishmentofbaselineandregularfollow-upevaluationswithacomprehensiveframeworkcenteredonlanguagedevelopment.Recentresearchinterestsalsoincludeunderstandingthevastdifferencesinoutcomesforchildrenwithhearingloss,understandingtherelationshipsbetweenneurocognitivedevelopmentandlanguageacquisitioninchildrenwithhearingloss,andusingoutcomestudiestoguideevidence-basedclinicalpractice.AftertheestablishmentofstandardizedMandarinlanguageassessments,outcomesresearchinMainlandChinahasthepotentialtoexpandbeyondauditoryawarenessandspeechperceptionstudies.
简介:Animpulseresponsetechniquehasbeeninvestigatedbyapplicationtotheopenscreensforobtainingsoundtransmissionloss.ThemeasurementsofsuchscreensaccordingtoISO140werealsopresented.ThepredictedresultscalculatedbyamodelwhichisbasedonHuygen’sprincipleandKirchhoff’sformulationhaveshowngoodagreementswiththeresultsobtainedbyimpulsemethod.Themethodrequiresnospecialistacousticfacilitiesandmeasurementsystemscanbeportable.
简介:Theeffectsofheatlossonthestructureoflaminarflamelets,whicharetheconstitutiveelementsofturbulentflamesunderthemostcommonoperatingconditions,areinvestigatedfortypicalaeronauticalgas-turbineoperatingconditionsattake-off.Themagnitudeofheatlossisquantifiedviathe"enthalpydefect"measuredwithrespecttoanadiabaticflame.Aproceduretogeneratelaminarflameletswithanassignedenthalpydefectattheboundariesisdevisedandappliedtononpremixedpropane/airflames,aspropanereproducestheessentialfeaturesofhigherhydrocarboncombustion.Itisfound,contrarytocommonlyheldbeliefs,thattheenthalpydefecthasasignificanteffectontheconcentrationnotonlyofminorspecies,butalsoofmainreactionproducts.Sucheffectsarefoundingeneraltobemorepronouncedforfuel-richconditions.Animpactisanticipatedontheformationrateofnitricoxides.Theeffectsofscalardissipationratearealsodiscussed.