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This paper introduces a new process simulator for micro-electro-mechanical systems. The open-source program, which has been developed via C/C+ + language along with the OpenGL library functions, significantly speeds up the design phase by providing realistic outcomes about the micro-fabrication processes involved. While anisotropic/isotropic etching of silicon wafers are of major interest, the developed software can conveniently simulate additive micro-fabrication processes such as doping and material deposition by extending its basic cellular automaton algorithm. Equipped with an integrated mask design editor, complex mask patterns can be generated by the software. Consequently, the simulation on the subsequent micro-fabrication processes that employ these complex mask patterns can be carried out in the same integrated environment. The paper also shows that the simulation results are in agreement with the experimental ones both qualitatively and quantitatively.

This paper investigates the optimal design of a four-stage gear train using genetic algorithms. Five different genetic encoding schemes, which incorporate various heuristic search techniques, are proposed to deal with the most critical constraints of the problem. The fitness criterion used by all genetic algorithms includes a merit function for minimising the size of the gearbox. The results show improvement in the design merit over previous approaches without reliance on the designer's interaction to avoid geometric constraint violations and facilitate the convergence.

The study reported in this paper is undertaken to develop a computer simulation and an optimum design and operation strategy for a general storage system. The influence of various design parameters on the total operation cost of the system for a general delivery regime is also studied. The computer program which incorporates a general procedure for the design and control of the pump-piping-storage system is presented. The main considerations in the reported study are the worst-case storage capacity analysis and the allowance for variations in the friction factors. The computer model of the system is applicable to any of pump-piping-storage system with appropriate changes in some of the system parameters. Two important parameters of the system are the average standby and operation times. The solution of the cost optimisation problem is undertaken using non-linear programming.