简介:AgraphGiscalledchromatic-choosableifitschoicenumberisequaltoitschromaticnumber,namelych(G)=χ(G).Ohba’sconjecturestatesthateverygraphGwith2χ(G)+1orfewerverticesischromaticchoosable.ItisclearthatOhba’sconjectureistrueifandonlyifitistrueforcompletemultipartitegraphs.Recently,Kostochka,StiebitzandWoodallshowedthatOhba’sconjectureholdsforcompletemultipartitegraphswithpartitesizeatmostfive.Butthecompletemultipartitegraphswithnorestrictionontheirpartitesize,forwhichOhba’sconjecturehasbeenverifiedarenothingmorethanthegraphsKt+3,2*(k-t-1),1*tbyEnotomoetal.,andKt+2,3,2*(k-t-2),1*tfort≤4byShenetal..Inthispaper,usingtheconceptoff-choosable(orL0-size-choosable)ofgraphs,weshowthatOhba’sconjectureisalsotrueforthegraphsKt+2,3,2*(k-t-2),1*twhent≥5.Thus,Ohba’sconjectureistrueforgraphsKt+2,3,2*(k-t-2),1*tforallintegerst≥1.
简介:老师在课堂上用实验演示了弹簧振子做简谐运动的周期T与振幅A无关,而取决于振子质量m和劲度系数k.为了便于记忆,老师给出了它的周期公式T=2πm/k~(1/2).这个公式是教材中没有的,老师也没有加以证明.我想,能否利用我所学的知识证明它呢?我头脑一下子兴奋起来了,课后就开始着手去证明了.在简谐运动过程中,弹簧的弹力是变化的,要
简介:Comparedwithaccuratediagnosis,thesystem’sselfdiagnosingcapabilitycanbegreatlyincreasedthroughthet/kdiagnosisstrategyatmostkvertexestobemistakenlyidentifiedasfaultyunderthecomparisonmodel,wherekistypicallyasmallnumber.BasedonthePreparata,Metze,andChien(PMC)model,then-dimensionalhypercubenetworkisprovedtobet/kdiagnosable.Inthispaper,basedontheMaengandMalek(MM)?model,anovelt/k-faultdiagnosis(1k4)algorithmofndimensionalhypercube,calledt/k-MM?-DIAG,isproposedtoisolateallfaultyprocessorswithinthesetofnodes,amongwhichthenumberoffault-freenodesidentifiedwronglyasfaultyisatmostk.ThetimecomplexityinouralgorithmisonlyO(2nn2).
简介:巡检式数字温度监控仪能自动定时检测并显示8个检测点的地址编号及温度值,在温度异常时产生报警信号和控制继电器动作,避免事故的发生和损失。应用K型热电偶变换器MAX6675可以很好地实现这一控制,并且电路简单可靠。