学科分类
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500 个结果
  • 简介:正确传播顺序与独立、相同的部件在平行系统的形成下面被关上,这被证明。作为一个应用程序,为平均数和有独立、相同的NBUE部件的一个平行系统的生活长度的变化的简单上面的界限被获得。而且,正确传播顺序也在在一些条件下面增加凸的转变下面被关上,这被证明。

  • 标签: RIGHT Spread序 封闭性质 排列 组合数学
  • 简介:Spread-sale,spreadingsalesnationwidethroughvariouschannels,asamarketingmethod,hasbeenintroducedtoChinasincetheearly1990s,andismovingtowardsstandardization.Tobringspread-saleundergovernmentsupervision,theMinistryofInternalTradedraftedtheManagementProvisionsonMultipleSpread-sale(forsolicitingopinions)in1994,aimingtostrengthenthelegalmanagementandinternalcontrolofthespread-salemarket.InAugust1994,the

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  • 简介:Widthspreadisusuallyconsideredinhotrolling,nevertheless,itcanbeignoreincoldrolling.Inordertocontrolthecrownandflatnessbettersimultaneouslyandrealizethedecouplingofcrownandflatness,thetransversedisplacementfunctionofstripisdefinedanddeduced.Thefactorsthataffectsthewidthspreadareanalyzingwiththefunction.Accordingtotheunchangedprincipleofvolumebeforeandafterrolling,theflatnessmodelwhichconsidersthewidthspreadisdeduced.Throughthemodel,thetransversemetalflowingofdifferentstandsanddifferentthicknessisanalyzing,itisfoundthatthewidthspreadisbiggestincoldrollingattheNo.1standbecauseofthemaximumthicknessandreductionandtheminimumdeformationresistance.Itgivesagoodfoundationforthedecouplingofcrownandflatness.

  • 标签: 冷轧带钢 宽展 最大厚度 位移函数 金属流动 变形阻力
  • 简介:Inpracticalparameterestimation,wehavealwayschoseneitherLeastSquaresEstimation(LSE)orRobustEstimation.Sincethedistributionofobservationsisunknown,toselectacorrectestimationmethodisverydifficult.Itiswellknownthatifobservationsincludegrosserrors,theresultofLSEwillbebadlycontaininated.Ontheotherhand,ifobservationsdonotincludeanygrosserrors,theresultofrobustestimationisnotasgoodasthatofLSE.Tosolvethisproblem,Wang(1999)developedanestimationmethodcalledInformationSpreadEstimation(ISE)basedontheinformationspreadprinciple.TheISEisaverygoodmethodforestimatingoneparameterwhichisveryrobust.However,mostofinstancesinsurveyingdataprocessingaremulti-parameters'estimation,owingtotheinherentrestrictionsofISE,itcannotbeappliedtothesurveyingdataprocessingdirectly.Toapplythegoodmethodtothefieldofsurveyingdataprocessingwidely,theauthorhasdonetheresearchdeeply.ThispaperappliesISEsuccessfullytotheadjustmentoflevelingnetworkbyusingthespecialtiesofleveling.

  • 标签: RESIDUAL ERROR data SNOOPING robust ESTIMATION
  • 简介:Todaywearepracticallywitnessingandexperiencingarealbotinvasion.Itisthereforepermissibletoaskoneselfwhatabotis(anditiscertainlynot“sciencefiction”).Thetruthisthis:theyareprogramsthatrespondautomaticallytorequests/queriesfromhumanusers.Butwherecanwefindthem?Inmanyfieldsorsectorsbutespeciallyininstantmessaging,forexample:Whatsapp,Telegram,Facebook,orMessenger.Itseemsthatwearetalkingaboutsomethingcomplicatedorverydifficult,however,evenweuserscancreateabotthatcanhelpusorotherstosimulateconversationsoractionsofthehumanbeinginordertomakeiteasieranactionortaskthatmayberepetitive.Nowithasbecome,inashorttime,afashionthatisspreadinginmanysectorsforitsversatility.Therealityisthattherearemanytypesofbots.Dependingonthesituationandourgoal,wewillchooseoneortheother.Butlet’sstartfromthebeginningandbeforethinkingabouthowtocreateabot,let’sseewhatabotisexactly.

  • 标签: BOT artificial intelligence(AI) human-computer interaction(HCI)
  • 简介:Pierson-MoskowitzSpectrum,JONSWAPSpectrumaswellasBretschneider-MitsuyasuSpectrumareusedinthispaperforanalyzingtheinfluenceofwaveenergydirectionalspreadonrefractionofwavespectrumduetobothcurrentandtopographyofseabed.Theauthor’scalculationindicatesthatsuchkindinfluenceonthecharacteristicvalueofwaveheightaswellastheaveragedirectionofwaveenergypropagationcannotbeignored.

  • 标签: WAVE SPECTRUM WAVE REFRACTION directional WAVES
  • 简介:这被显示出一个平行系统与的全部的生活独立、相同(i.i.d)指数的部件比有象系统的一样的平均数的指数的生活在正确传播顺序是更小的。作为应用,为平均数和有i.i.dNBUE部件的一个平行系统的生活长度的变化的简单上面的界限被建立,以及NBUE和指数的随机的变量的卷绕旋转的保藏性质。

  • 标签: 并行系统 优化 指数分布 NBUE
  • 简介:Arrayprocessingistoprocessthesignalscarriedbythepropagatingwavesreceivedatanarrayofsensors.Whenthesignalspropagatethroughthepracticalrandomtime-variantmedium,theirwavefrontscanshowtheprogres-sivelossesofcoherencewithincreasingspatialseparation.Thesedecorrelationsofwavefrontsresultinanangularspreadinthewavenumberspectrumcenteredaboutthetruesignaldircction-of-arrival.Thispaperputstheemphasisuponthearrayprocessingoftheangular-spreadsignalwhichiscalledtheGeneral-izedDirectional(GD)signalandaimstomatcharrayprocessingtothissignalmodelintheenergysense.Inthispaper,wealsopresentamethodofthecom-putersimulationorthegeneralizeddirectionalsignalmodel.Someresultsofcomputersimulationexperimentsandlake-tcstsinXinanjiangRiveraregiven.

  • 标签: directional MATCH COHERENCE spread compensate ANGULAR
  • 简介:Thestatisticcharacteristicsofchaoticsequencesgeneratedbyimprovedlogistic-mapareanalyzedanditisfoundthatimprovedlogistic-mapchaoticsequenceshavegoodcorrelationandtheycanbeusedasaddresssequencesinspread-spectrumcommunication.Thediscrete-timesynchronizationofHenonmapisimmediate.Weapplythediscrete-timesynchronizationtochaoticspread-spectrumcomuunicationandproposeanoriginalcommunicationscheme.Thesimulationshowsthattheapplicationissuccessful.

  • 标签: 混沌扩频通信 离散时间同步化 混沌信号 仿真
  • 简介:Inthispaper,theangularspreadoftheSAWbeamdiffractedbyBragggrating,denotedbyδθ1,isana-lysedbasedontheequationsofthedeflectionangleandthedeflectioneffciency.AparameterδθBisde-finedtoreferto"Braggangularspectrumwidth"ofthegrating.Theimportanceofthisparameterindis-tinguishingtheangularspreadrangeofthedeflectedbeamfordifferentregimesisdiscussedaswell.Itisshowfromtheanalysisthatifthespreadangleoftheincidentbeamlabelledwithδθincislargethanthe"Braggwitdthoftheangularspectrum"ofthegrating,thespreadangleδθ1ofthedeflectedbeamwillequaltoδθB;butiftheangulardivergenceoftheincidentbeamislessthanδθB,thenδθ1=δθincExperimentally,fourkindsofsampleswithdifferentconfigurationsareinvestigatedbyopticalmethod,twoofwhichoperateintheregimeofδθinc<<δθBandtheotherscorrespondtothecaseintheregimeofδθinc>>δθB.Thewidthsoftheangularspreadoftheinciden

  • 标签: BRAGG GRATING INCIDENT deflection spread DIVERGENCE
  • 简介:PerformancesofBPSK,balanced-quaternarymodulation,dual-quaternarymodulationandcomplex-quaternarymodulationindirect-sequencespectrum-spread(DS-SS)systemarediscussedinthispaper.Basedonthecriterionthepoweroforiginalsignalisthesame,itisshownthatcomplex-quaternarymodulationhasthebestperformance,anddual-quaternarymodulationdegrades2dB.Moreover,thefrequencyefficientofthetwomodulationsis2bit/Hz.Balanced-quaternaryhasthesameperformanceasBPSKwithfrequencyefficient1bit/Hz.

  • 标签: Modulation Direct-sequence spectrum-spread FREQUENCY efficient.
  • 简介:AbstractThe current unprecedented Monkeypox outbreaks emergence and spread on non-endemic countries has led to over 3413 laboratory confirmed cases and one death, and yet, does not constitute a public health emergency of international concern as June 23th 2022. We urgently call for collective regional and global partnership, leadership commitment and investment to rapidly strengthen and implement Monkeypox World Health Organization outbreak Preparedness and emergency response actions plans implementation against Monkeypox outbreak. Given the importance of human-animal-environment interface and transmission dynamics, fostering global and regional One Health approach partnership and multisectoral collaboration programs have timely and robust sustained investment benefits on poverty-linked Monkeypox and other emerging epidemics population-based programs, while leveraging from lessons learnt. Moving forward requires addressing priority research questions listed and closing the knowledge gaps for Monkeypox and others neglected tropical diseases roadmap implementation in vulnerable and at risk countries.

  • 标签: Monkeypox Outbreak Neglected tropical diseases Poverty One Health Preparedness Emergency response Vaccination Research
  • 简介:AbstractZika virus (ZIKV) may cause severe microcephaly in newborn babies and Guillain-Barré syndrome in some adults. In recent decades, its range has expanded in 86 countries. There are two ecologically and evolutionarily district cycles: urban cycle and sylvatic cycle. This work aimed to estimate the urban and sylvatic cycle areas of ZIKV throughout the world. The occurrence records of vectors, non-human primate hosts, and ZIKV were collected. We chose historical climate data, predicted vectors distribution, human population density, and elevation data as the variables to fit the maximum entropy model (MaxEnt). Current risk area and future prediction were performed with global climate models (GCMs) and shared socioeconomic pathways (SSPs). Predicting the ZIKV risk area would help tailor related control strategies. The results indicated that 16.6% of the world’s landmass (except Antarctica) is a risk area in the urban cycle. Approximately 6.22 billion people (78.69% of the global population) live in the risk area, with the vast majority in South Asia, tropical Africa, South America, North America, and countries around the Mediterranean Sea. Future climate change decreases the risk area of ZIKV. This study also suggested that the sylvatic cycle happened between the Tropic of Cancer and the Tropic of Capricorn. The overlap region of the urban and sylvatic cycles could be hotpots that ZIKV spill from the sylvatic to the urban cycle. It is indicated that long-term passenger screening, mosquito surveillance, and control are necessary.

  • 标签: Zika virus Aedes aegypti Aedes albopictus Species distribution modeling MaxEnt Urban cycle Sylvatic cycle
  • 简介:Spreadoffiresmokeintheelevatorshaftofahigh-risebuildingisinfluencedbymanydrivingfacts.Wesimulatesmokespreadingintheelevatorshaft,stairroom,andpre-chamberwithandwithoutdifferentsuppliedpressurizedair.Thesimulationshowsthatsmokemovesveryfastintheelevatorshaft.Whena12floorhigh-risebuildingisinfire,smokecanfilluptheelevatorshaftinlessthan1.5minafterafirestarted,temperatureintheelevatorshaftcanbehigherthan187?Cin5min,andtheconcentrationofCOcanalsoreachahighlevel.Theelevatorshafthasaverylowvisibilityinlessthanabout100s.

  • 标签: 高层建筑火灾 火灾烟雾 电梯井 模拟 烟气蔓延 空气传播
  • 简介:Inopticalscanningholography,onepupilproducesasphericalwaveandanotherproducesaplanewave.Theyinterferewitheachotherandresultinafringepatternforscanningathree-dimensionalobject.Theresolutionofthehologramreconstructionisaffectedbythepointspreadfunction(PSF)oftheopticalsystem.Inthispaper,wemodulatethePSFbyaspiralphaseplate,whichsignificantlyenhancesthelateralanddepthresolution.Weexplainthetheoryforsuchresolutionenhancementandshowsimulationresultstoverifytheefficacyoftheapproach.

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  • 简介:Investigatinghowcropdomesticationandearlyfarmingmediatedcropattributes,distributions,andinteractionswithantagonistsmayshedlightontoday'sagriculturalpestproblems.Cropdomesticationgenerallyinvolvedartificialselectionfortraitsdesirabletoearlyfarmers,forexample,increasedproductivityoryield,andenhancedqualities,thoughinvariablyitalteredtheinteractionsbetweencropsandinsects,andexpandedthegeographicalrangesofcrops.Thus,somestudiessuggestthatwithcropdomesticationandspread,insectpopulationsonwildcropancestorsgaverisetopestiferousinsectpopulationsoncrops.Here,weaddressedwhethertheemergenceofcornleafhopper(Dalbulusmaidis)asanagriculturalpestmaybeassociatedwithdomesticationandearlyspreadofmaize(Zeamaysmays).WeusedAFLPmarkersandmitochondrialCOIsequencestoassesspopulationgeneticstructuringandhaplotyperelationshipsamongcornleafhoppersamplesfrommaizeanditswildrelativeZeadiploperennisfrommultiplelocationsinMexicoandArgentina.Weuncoveredsevencornleafhopperhaplotypescontainedwithintwohaplogroups,onehaplogroupcontaininghaplotypesassociatedwithmaizeandtheothercontaininghaplotypesassociatedwithZ.diploperennisinamountainoushabitat.Withinthefirsthaplogroup,onehaplotypewaspredominantacrossMexicanlocations,andanotheracrossArgentineanlocations;bothwereconsideredpestiferous.Wesuggestedthatthedivergencetimesofthemaize-associatedhaplogroupandofthe"pestiferous"haplotypesarecorrelatedwiththechronologyofmaizespreadfollowingitsdomestication.Overall,ourresultssupportahypothesispositingthatmaizedomesticationfavoredcornleafhoppergenotypespreadaptedforexploitingmaizesothattheybecamepestiferous,andthatwiththegeographicalexpansionofmaizefarming,cornleafhoppercolonizedZ.diploperennis,ahostexclusivetosecludedhabitatsthatservesasarefugeforarchaiccornleafhoppergenotypicdiversity.B

  • 标签: Dalbulus maidis HAPLOTYPE network analysis PERENNIAL
  • 简介:给出矩阵Sharp的一个新的刻画,由此得到(半)正定矩阵Sharp与其平方矩阵Sharp之间的关系.我们还讨论正规矩阵的*与减之间的关系,推广了关于Hermmite矩阵的相应结果.

  • 标签: 矩阵 Sharp序 核心幂零分解 *序 减序 Hermmite矩阵