Lognormal faib ua lub luag haujlwm tseem ceeb hauv kev tsim qauv tsim vim tias qhov tsis zoo ntawm engineering phenomena yog qee zaum lub cev ua tsis tau. Kev siv cov kev faib tawm tsis zoo muaj nyob hauv cov lus piav qhia ntawm qaug zog tsis ua haujlwm, tus nqi tsis ua haujlwm, thiab lwm yam tshwm sim uas cuam tshuam nrog ntau yam ntaub ntawv
Kev faib khoom siv tsis raug siv rau dab tsi?
Qhov kev faib tawm tsis raug siv los piav qhia cov hloov pauv, qhov kev faib ib txwm siv los piav qhia txog qhov sib txawv. Txawm li cas los xij, qhov sib txawv uas paub tias tsis txhob noj cov txiaj ntsig tsis zoo yog ib txwm muab qhov kev faib tawm tsis zoo dua li qhov kev faib tawm ib txwm.
Kev ntsuas kev faib tawm tsis raug cai yog dab tsi?
A lognormal (log-normal or G alton) distribution is a probability distribution with a nquag faib logarithm … Skewed distributions with low mean values, large variance, and all-positive values feem ntau haum rau hom kev faib tawm no. Cov nqi yuav tsum yog qhov zoo vim tias log(x) tsuas yog muaj rau qhov zoo ntawm x.
Koj yuav txiav txim siab li cas yog tias kev faib khoom tsis raug?
qhov twg σ yog tus qauv ntsuas (thiab yog tus qauv sib txawv ntawm lub cav ntawm qhov kev faib tawm), θ yog qhov chaw ntsuas qhov ntsuas thiab m yog qhov ntsuas ntsuas (thiab tseem yog qhov nruab nrab ntawm kev faib khoom). Yog x=θ, ces f(x)=0 Cov ntaub ntawv uas θ=0 thiab m=1 yog hu ua tus qauv lognormal faib.
Dab tsi ua rau kev faib khoom tsis raug cai?
Lognormal distributions feem ntau tshwm sim thaum muaj qhov qis qis nrog qhov sib txawv loj, thiab thaum qhov tseem ceeb tsis tuaj yeem tsawg dua xoom. Kev faib tawm ntawm cov txiaj ntsig nyoos yog li skewed, nrog rau tus Tsov tus tw txuas ntxiv zoo ib yam li tus Tsov tus tw pom nyob rau hauv nplai-dawb thiab broad-scale systems.
