Typescript.Thesis (Ph. D.)--University of Hawaii at Manoa, 1985.Bibliography: leaves 101-106.Microfilm.xxiv, 193 leaves, bound ill. 29 cmThe effect of weather on agricultural production and processing is of vital concern to all farmers. Grain drying systems, especially in the developing world, are complex and weather dependent 0 Because of the large degree of risk due to the random nature of weather, farmers in developing nations have had problems in the adoption of artificial drying. The centralized grain drying facilities are usually designed without considering adequately the random effects of weather. As a result, most grain drying investments are found to be uneconomical. Efficient design and economic operation can only be achieved through better understanding of all the relevant variables and their interrelationships in the entire drying system. A general simulation model for grain drying (WEGDM) was developed ~ including the pertinent weather variables, either stochastic or deterministic, into a meaningful analysis. It is built to be general enough to simulate most grain drying systems. The model consists of three major computer programs, namely, Simulation Program for Weather Variables (SPWV); Simulation Program for Grainflow, Drying and Management (SPGDM); and Simulation Program for Financial Analysis (SPFA). The SPWV program simulates sunny and no-sunny days for grain drying harvest and no-harvest days; wind and no-wind days for grain harvesting; using Markov Transition Probabilities. The SPGDM program simulates the amount of grain flow, moisture content of the grain and grain losses in various stages of grain handling and processing. The program SPFA is designed to calculate and gather all pertinent cost information into a meaningful economic analysis. The Net Present Value (NPV) of cash flow has been considered as a decision criterion of the model. The main program with 23 subroutines in the FORTRAN 77 language has been designed to make the program flexible and easy to follow. The grain paddy and the Los Banos area of the Philippines were chosen for development and verification of this model. The application of the model is extensive. Design of a grain processing complex, economic analysis of an existing plant, feasibility study of a grain drying plant and evaluation of alternative drying strategies are the important areas of application of the model
