[en] In the Nuclear Engineering Research Laboratory of University of Tokyo, more than 10 short period workshops called Yayoi workshop have been held yearly as one of the activities of the joint utilization of the reactor 'Yayoi' and an electron linear accelerator by universities. In this report, the gists of the lectures given at the workshop on particle process which was held on August 8, 1994, are summarized. The development of scientific and technological computations in atomic energy field is briefly mentioned. The recent advance of numerical fluid dynamics is conspicuous, but still it includes many unsatisfactory points. This workshop was held, collecting the computation method using particles and the computation method without using grids for the application to fluids. Lectures were given on the SPH method in astrophysics, fragmentation of isothermal sheet-like clouds, lattice Bhatnagar-Gross-Krook method for fluid dynamics and compressible, thermal and multi-phase models, the analysis techniques for compressible and incompressible fluids including movable boundary by PIC method, the numerical computation of high Reynolds number flow by gridless method, the development of particle method for analyzing incompressible viscous flow accompanied by breaker, the calculation of neutron and photon transport by Monte Carlo method using vector and parallel computers and the paradigm of super-parallel computation. (K.I.)