We have already proposed DTSS (event aware Dynamic Time Step Synchronization method) for speeding up moving objects (MOs) simulation, e.g. aircraft, ships, vehicles and so on, and evaluated it on the HLA (High Level Architecture, IEEE1516) computer cluster environment. However, speeding up the simulation for a number of MOs on a single processor is required as well, when the size of the problem is increased. In this paper, we propose DTSSRT (DTSS for Road Traffic simulation) that can speed up the simulation by reducing the simulation cost of each MO and the synchronization cost between MOs without degrading simulation accuracy. For evaluating DTSS-RT, we employed a road traffic sub-simulator of RoboCup rescue simulation. The results show that the performance of the simulation based on DTSS-RT is improved approximately 2 to 3 times over that of the conventional method except when the situation includes a heavy traffic jam.

Good load balancing is the key to deriving maximal performance from multiprocessors. Several successful dynamic load balancing techniques on tightly-coupled multiprocessors have been developed. However, load balancing is more difficult on loosely-coupled multiprocessors because inter-processor communication overheads cost more. Dynamic load balancing techniques have been employed in a few programs on loosely-coupled multiprocessors, but they are tightly built into the particular programs and not much attention is paid to scalability. We have developed a dynamic load balancing scheme which is applicable to OR-parallel programs in general. Processors are grouped, and work loads of groups and processors are balanced hierarchically. Moreover, it is scalable to any number of processors because of this multi-level hierarchical structure. The scheme is tested for the all-solution exhaustive search Pentomino program on the mesh-connected loosely-coupled multiprocessor Multi-PSI, and speedups of 28.4 times with 32 processors and 50 times with 64 processors have been attained.