Ndife akatswiri akulu kwambiri ku China opanga komanso fakitale yamakina odziyika okha mumsewu wa convex.Malinga ndi ziwerengero zapadziko lonse lapansi, ngozi zapamsewu zidzachepetsedwa ndi 30% pambuyo potengera mizere ya convex, ovulala komanso kuwonongeka kwachuma kumachepetsedwa kwambiri.Zotsatira zake akatswiri amalimbikitsa kugwiritsa ntchito mzere wamtunduwu ngati mzere wokhazikika wachitetezo cha magalimoto.