Investigation of an elevator dispatcher system

To provide an efficient elevator system, a variety of diverse and sometimes conflicting constraints have to be solved. This paper focuses on using discrete event simulation as a means to model and explore elevator dispatching strategies. Witness simulation software has been used as a test-bed for model building, simulation and some experimentation. Model building using Witness model elements is described in detail followed by two different elevator call strategies. The main steps in the methodology are described with reference to a single elevator servicing a five-storey office building. The elevator call strategies are simulated and results compared. It was found that the data set significantly skews the results and overshadows any efficiency gains that might be possible from the different dispatching strategies. The paper concludes with the need to carefully select the data set as the basis for simulation comparisons and outlines future work required

Effect of Different Phosphorus Levels on Growth and Yield of Wheat under Water Stress Conditions

Water stress and low phosphorus availability are the limiting factors for growth and yield of wheat. Five different phosphorus levels (P = 0, 30, 60, 90, 120 kg ha-1) with three water stress levels (I1 = well-irrigated, I2 = water stress at reproductive stage and I3 = water stress both at vegetative + reproductive stages) were applied to check their effects on growth and yield of wheat. Higher application of phosphorus with optimum irrigation showed significant effect on growth of wheat. Higher phosphorus application rate compensate the effect of water stress conditions both at vegetative and reproductive stages. Drought stress at vegetative + reproductive stages was more drastically affected as compared to stress at reproductive stage. Lower phosphorus application rate with water stress caused maximum reduction in plant height, number of tillers, spike length, number of grains spike-1, 1000 grains weight, grain yield and straw yield. It was concluded that application of phosphorus at higher rate could compensate drastic effect of water stress. On overall performance, application of phosphorus at the rate of 120 kg ha-1 showed better results under water stress conditions as compared to other phosphorus levels. Keywords: - wheat, water stress, phosphorus, growth, yield