Spatial crowdsourcing is an effective and novel method. In crowdsourcing systems. a centralized platform is traditionally used to allocate tasks and select workers. Centralized platforms always face following challenges: 1) How to ensure the rationality of tasks allocating; 2) How to ensure the payments of workers in the system when dishonest requesters exist; 3) How to ensure the max... https://www.roneverhart.com/Seagate-Exos-7E2-ST1000NM0008-1TB-7-2K-RPM-SATA-6Gb-s-512n-128MB-3-5-Hard-Drive/