My research interest is kinetic simulation of collective phenomena in magnetic confinement fusion plasmas, mostly tokamak plasmas. Nowadays virtually all processes of interest in tokamaks, e.g. micro-turbulence and anomalous transport,equilibrium and macroscopic stability, physics of energetic particles, and the physics of plasma-wall interaction,are subjects of intensive computational studies based on plasma kinetic equations. There are two basic approaches to kineticsimulation, the continuum approach that directly discretizes the kinetic equation using conventional methods such as thefinite difference method, the finite element method or the spectral method, and the Particle-in-Cell approach that follows the motion of alarge number of simulation particles as a statistical sampling of the phase-space. My interest is mainly on thelatter approach. Over the years I have devised a number of novel numerical algorithms for solving computational problems that arise in the simulation of the electrons with magnetic field turbulence simulation code with kinetic ions and electrons, and realistic tokamak equilibrium profiles. Recently a fluid electron model has been added for the study of energetic particles driven waves.