简介：Someresearchers,runninginstructors,andcoacheshavesuggestedthatthe'optimal'footstrikepatterntoimproveperformanceandreducerunninginjuriesistolandusingamid-orforefootstrike.Thus,ithasbeenrecommendedthatrunnerswhousearearfootstrikewouldbenefitbychangingtheirfootstrikealthoughthereislittlescientificevidenceforsuggestingsuchachange.Therearfootstrikeisclearlymoreprevalent.Themajorreasonsoftengivenforchangingtoamid-orforefootstrikeare(1)itismoreeconomical;(2)thereisareductionintheimpactpeakandloadingrateoftheverticalcomponentofthegroundreactionforce;and(3)thereisareductionintheriskofarunning-relatedinjuries.Inthispaper,wecritiquethese3suggestionsandprovidealternateexplanationsthatmayprovidecontradictoryevidenceforalteringone'sfootstrikepattern.Wehaveconcluded,basedonexaminingtheresearchliterature,thatchangingtoamid-orforefootstrikedoesnotimproverunningeconomy,doesnoteliminateanimpactatthefoot-groundcontact,anddoesnotreducetheriskofrunning-relatedinjuries.

简介：China’s ,China,China. 

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简介：Tujiapeople’straditionalbrocadehasvariedstylesinitspattern,andthecolorsarealsoverybright.Tujiapeopleshowtheirownhumanisticspiritsandaesthetichabitstotheworldbymakingbrocade.Beneaththegorgeouscolor,itistheirlife-lovingandnature-awingattitude.

简介：到在CMOSimage传感器(顺式)中消除固定模式噪音(FPN)的一个双采样电路被介绍。两倍采样被列开关电容器放大器直接实现。并且偏移量赔偿被加到放大器压制列FPN。放大器在64x64顺式被嵌入并且成功地制作了与特许0。35μm过程。Theoryanalysis和电路模拟显示FPN能从毫伏特被压制到微伏。测试结果证明FPN比8小点模数转换器的一最少重要的位小。FPN被归结为可接受的水平，两倍采样技术与开关电容器放大器实现了。

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简介：Conventionalcameracalibrationthatemployscalibrationtargetsisacommonlyusedmethodtoacquireacamera'sintrinsicand/orextrinsicparameters.Thecalibrationtargetsareusuallydesignedasperiodicarraysofsimplehigh-contrastpatternsthatprovidehighlyaccurateworldcoordinatesystempointsandthecorrespondingimagepixelcoordinatesystempoints.Theexistingpixelcoordinateextractionalgorithmscanreachasub-pixellevel;however,theytreateachsinglepatterninoneimageasanindependentindividual,whichmakesitdifficulttofurtherimproveextractionaccuracy.Inthispaper,anovelmethodisproposedbyutilizingtheperiodicarrangementcharacteristicsofthecalibrationtargetpatternasaglobalconstrainttoimprovethecalibrationaccuracy.Basedonacamera'spinholemodel,theintersectionpointoftwofittedcurvesisusedasanoptimizedpixelpointtoreplacetheinitialone.Followingthepixelcoordinateoptimizationprocedures,experimentswereperformedusingrealdatafroma3Dlaserlinescannerandadynamicprecisioncalibrationtarget.Ourresultsshowthattherelativeerrorsofcamerahomographymatrixelementsobtainedbytheproposedoptimizationmethodwerereducedcomparedwiththecommonlyusedmethod.Theaveragecoordinatemeasurementaccuracycanbeimprovedbynearly0.05mm.Itisshownthattheproposedoptimizationmethodcanenhancethecameracalibrationaccuracy,especiallywhentheextractedpixelsareofpoorerprecision.

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