Tham khảo tài liệu 'robotic subsurface mapping using gpr part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Figure 37 Algorithm for distributed migration Even with all the optimization it still took about 30 minute to migrate about 180000 points. This is completely unacceptable because it does not facilitate a real time operation of the system. Since the migration process is inherently a parallel problem we develop a distributed version of the above algorithm. The distributed migration program uses idle workstations on the network. The programs on different workstations communicate through the network to exchange data. There are basically two different programs for executing the distributed migration. First is the coordinator program which starts the client programs distribute the data and combine the individual results. Second is the client program which actually migrates the individual scans based on instructions from the coordinator program. Algorithm for the distributed migration program is shown in Figure 37. In the current implementation each client program loads the whole data set although it might only need a sub 66 set of them. This can be a problem if the whole data set does not fit in the workstation memory. In this case the client program can be easily modified so it only loads a subset of the data that is needed to migrate a particular scan. The features of the distributed migration algorithm are Much faster execution time depends on the number of workstation used . Automatic load balancing. Since the tasks are distributed as small pieces at a time every time a client process finishes migrating some scans it is automatically instructed to migrate a new set of scans. So we can use a mix of fast and slow workstations without any detrimental effect. Ability to process a massive data set. With a minor modification the distributed migration program can be used to migrate a very large data set which will not fit in the memory of a single workstation. The gain in the execution time is almost linear with the number of workstation used. Of course there is some .
