چکیده:
In this study, we considered an inflationary inventory control model under non-deterministic conditions. We assumed the inflation rate as a normal distribution, with any arbitrary probability density function (pdf). The objective function was to minimize the total discount cost of the inventory system. We used two methods to solve this problem. One was the classic numerical approach which turned out to be prohibitively difficult. The other was a proposed combination method which used Simpson approximation and particle swarm optimization (PSO). To illustrate the theoretical results, we have provided numerical examples.
خلاصه ماشینی:
Most of them used simple or hybrid methods with changed or combined parameters of PSO with other algorithms to find the answer: Sedighizadeh and Masehian (2009); Orand, Mirzazadeh, and Ahmadzadeh (2012); Parsopoulos, Skouri and Vrahatis (2008); Fatih Taşgetiren and Liang (2003); Tsai and Yeh (2008); Hsu, Tsou and Yu (2009); Chen and Su (2009); Domoto, Okuhara, Ueno and Ishii (2007); Varga, Király and Abonyi (2013); Goh Sue-Anna, S.
The following notations were used in the mathematical model: Inflation rate per unit time Probability density function (pdf) of Mean value of Standard deviation of Interest rate per unit time Demand rate per unit time Constant deterioration rate, where 0<θ<1 Inventory holding cost (for ) and shortage cost (for ) per unit per unit time at time zero Per unit purchase cost of the item at time zero Ordering cost per order at time zero Replenishment time interval Proportion of time in any given inventory cycle, which orders can be filled from the existing stock EDC Expected present value of costs Number of Particle Iteration Position particle in the iteration Velocity particle in the iteration Fitness particle in the iteration Best personal position of particle in the iteration Best group position of particles in the iteration Cognitive (individual) learning rate Social (group) learning rate Uniformly distributed random numbers in the range 0 and 1 Coefficient of improvement PSO The Discounted Cost Model According to the inventory system costs, we considered EDCR, EDCP, EDCH and EDCS as the expected present value of the ordering, purchasing, carrying and shortage, respectively (for further elaboration, see reference Mirzazadeh, 2007, pp.