简介:Spread-sale,spreadingsalesnationwidethroughvariouschannels,asamarketingmethod,hasbeenintroducedtoChinasincetheearly1990s,andismovingtowardsstandardization.Tobringspread-saleundergovernmentsupervision,theMinistryofInternalTradedraftedtheManagementProvisionsonMultipleSpread-sale(forsolicitingopinions)in1994,aimingtostrengthenthelegalmanagementandinternalcontrolofthespread-salemarket.InAugust1994,the
简介:Widthspreadisusuallyconsideredinhotrolling,nevertheless,itcanbeignoreincoldrolling.Inordertocontrolthecrownandflatnessbettersimultaneouslyandrealizethedecouplingofcrownandflatness,thetransversedisplacementfunctionofstripisdefinedanddeduced.Thefactorsthataffectsthewidthspreadareanalyzingwiththefunction.Accordingtotheunchangedprincipleofvolumebeforeandafterrolling,theflatnessmodelwhichconsidersthewidthspreadisdeduced.Throughthemodel,thetransversemetalflowingofdifferentstandsanddifferentthicknessisanalyzing,itisfoundthatthewidthspreadisbiggestincoldrollingattheNo.1standbecauseofthemaximumthicknessandreductionandtheminimumdeformationresistance.Itgivesagoodfoundationforthedecouplingofcrownandflatness.
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.
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.
简介:Pierson-MoskowitzSpectrum,JONSWAPSpectrumaswellasBretschneider-MitsuyasuSpectrumareusedinthispaperforanalyzingtheinfluenceofwaveenergydirectionalspreadonrefractionofwavespectrumduetobothcurrentandtopographyofseabed.Theauthor’scalculationindicatesthatsuchkindinfluenceonthecharacteristicvalueofwaveheightaswellastheaveragedirectionofwaveenergypropagationcannotbeignored.
简介:Arrayprocessingistoprocessthesignalscarriedbythepropagatingwavesreceivedatanarrayofsensors.Whenthesignalspropagatethroughthepracticalrandomtime-variantmedium,theirwavefrontscanshowtheprogres-sivelossesofcoherencewithincreasingspatialseparation.Thesedecorrelationsofwavefrontsresultinanangularspreadinthewavenumberspectrumcenteredaboutthetruesignaldircction-of-arrival.Thispaperputstheemphasisuponthearrayprocessingoftheangular-spreadsignalwhichiscalledtheGeneral-izedDirectional(GD)signalandaimstomatcharrayprocessingtothissignalmodelintheenergysense.Inthispaper,wealsopresentamethodofthecom-putersimulationorthegeneralizeddirectionalsignalmodel.Someresultsofcomputersimulationexperimentsandlake-tcstsinXinanjiangRiveraregiven.
简介:Thestatisticcharacteristicsofchaoticsequencesgeneratedbyimprovedlogistic-mapareanalyzedanditisfoundthatimprovedlogistic-mapchaoticsequenceshavegoodcorrelationandtheycanbeusedasaddresssequencesinspread-spectrumcommunication.Thediscrete-timesynchronizationofHenonmapisimmediate.Weapplythediscrete-timesynchronizationtochaoticspread-spectrumcomuunicationandproposeanoriginalcommunicationscheme.Thesimulationshowsthattheapplicationissuccessful.
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
简介:PerformancesofBPSK,balanced-quaternarymodulation,dual-quaternarymodulationandcomplex-quaternarymodulationindirect-sequencespectrum-spread(DS-SS)systemarediscussedinthispaper.Basedonthecriterionthepoweroforiginalsignalisthesame,itisshownthatcomplex-quaternarymodulationhasthebestperformance,anddual-quaternarymodulationdegrades2dB.Moreover,thefrequencyefficientofthetwomodulationsis2bit/Hz.Balanced-quaternaryhasthesameperformanceasBPSKwithfrequencyefficient1bit/Hz.
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.
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.
简介:Spreadoffiresmokeintheelevatorshaftofahigh-risebuildingisinfluencedbymanydrivingfacts.Wesimulatesmokespreadingintheelevatorshaft,stairroom,andpre-chamberwithandwithoutdifferentsuppliedpressurizedair.Thesimulationshowsthatsmokemovesveryfastintheelevatorshaft.Whena12floorhigh-risebuildingisinfire,smokecanfilluptheelevatorshaftinlessthan1.5minafterafirestarted,temperatureintheelevatorshaftcanbehigherthan187?Cin5min,andtheconcentrationofCOcanalsoreachahighlevel.Theelevatorshafthasaverylowvisibilityinlessthanabout100s.
简介:Inopticalscanningholography,onepupilproducesasphericalwaveandanotherproducesaplanewave.Theyinterferewitheachotherandresultinafringepatternforscanningathree-dimensionalobject.Theresolutionofthehologramreconstructionisaffectedbythepointspreadfunction(PSF)oftheopticalsystem.Inthispaper,wemodulatethePSFbyaspiralphaseplate,whichsignificantlyenhancesthelateralanddepthresolution.Weexplainthetheoryforsuchresolutionenhancementandshowsimulationresultstoverifytheefficacyoftheapproach.
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