3,152,219 research outputs found

    THE PACKING SIMULATION MODEL

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    The Packing Simulation Model is a microcomputer application program designed for researchers, extension personnel, bankers, packing managers, or other specialists who plan the operations of a packing facility or simulate its financial performance. PACKSIM produces pro forma financial statements for packing facilities based on flexible crop mixes and packing assumptions. Variations can be made in the product harvest schedule, price, quality, quantity, input costs and requirements, packing efficiency, overhead, and loan terms.Research and Development/Tech Change/Emerging Technologies,

    A ducted wind turbine simulation model for building simulation

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    Power production is shifting away from centralized generation plants to production of heat and power at the point of demand. A technology that may play a part in this shift is the ducted wind turbine (DWT). The emergence of small building integrated micro turbines opens up the possibility of utilizing the differential pressures occurring around buildings for local power production. This paper describes work to develop and test a simple mathematical model of a ducted wind turbine and its integration within a building simulation tool. A case study in which the simulation model will be used to analyse of the likely power output from a building incorporating ducted wind turbines within the façade is also presented

    A sand wave simulation model

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    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological numerical model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water surface and a general bed load formula. The water movement is coupled to the sediment transport equation with a seabed evolution equation. The domain is non-periodic in both directions. The spatial discretisation is performed by a spectral method based on Chebyshev polynomials. A fully implicit method is chosen for the discretisation in time. Firstly, we validate the model mathematically by reproducing the results obtained using a linear stability analysis for infinitely small sand waves. Hereby, we investigate a steady current situation induced by a wind stress applied at the sea surface. The bed forms we find have wavelengths in the order of hundreds of metres when the resistance at the seabed is relatively large. The results show that it is possible to model the initial evolution of sand waves with a numerical simulation model. Next, we investigate the influence of the chosen turbulent viscosity parameterisation by comparing the constant viscosity model with a depth dependent viscosity. This paper forms a part of a study to investigate the intermediate term behaviour of sand waves

    Software-Engineering Process Simulation (SEPS) model

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    The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments

    NRxx Simulation of Microflows with Shakhov Model

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    In this paper, we propose a method to simulate the microflows with Shakhov model using the NRxx method developed in [4, 5, 6]. The equation under consideration is the Boltzmann equation with force terms and the Shakhov model is adopted to achieve the correct Prandtl number. As the focus of this paper, we derive a uniform framework for different order moment systems on the wall boundary conditions, which is a major difficulty in the moment methods. Numerical examples for both steady and unsteady problems are presented to show the convergence in the number of moments.Comment: 31 pages, 10 figure

    GAMMA; a simulation model for ageing, pensions and public finances

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    To answer policy questions that have intergenerational implications, a computable simulation model should obey four conditions, it should: incorporate long-term demographic developments; include a detailed modelling of the public sector; decompose the population into several generations; account for the behaviour of the various economic agents. This document describes and illustrates a model that meets all these conditions. It is an applied general equilibrium model that is based on generational accounting principles named GAMMA (Generational Accounting Model with Maximizing Agents).
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