393,602 research outputs found

    Distributed Simulation of Heterogeneous and Real-time Systems

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    This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily composeable. Evaluating such large systems requires tools that integrate all components in a systematic, well-defined manner. This work leverages existing frameworks to facilitate the integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation

    Flexible operation of supercritical power plant via integration of thermal energy storage

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    © 2018 The Author(s).This chapter presents the recent research on various strategies for power plant flexible operations to meet the requirements of load balance. The aim of this study is to investigate whether it is feasible to integrate the thermal energy storage (TES) with the thermal power plant steam-water cycle. Optional thermal charge and discharge locations in the cycle have been proposed and compared. Dynamic modeling and simulations have been carried out to demonstrate the capability of TES integration in supporting the flexible operation of the power plant. The simulation software named SimuEngine is adopted, and a 600 MW supercritical coal-fired power plant model is implemented onto the software platform. Three TES charging strategies and two TES discharging strategies are proposed and verified via the simulation platform. The simulation results show that it is feasible to extract steam from steam turbines to charge the TES and to discharge the stored thermal energy back to the power generation processes. The improved capability of the plant flexible operation is further studied in supporting the responses to the grid load demand changes. The results demonstrated that the TES integration has led to much faster and more flexible responses to the load demand changes.Peer reviewe

    The role of primitive part modelling within an integrative simulation environment

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    The component-based modeling approach to the simulation of HVAC systems has been in used for many years. The approach not only supports plant simulation but also allows the integration of the building and plant domains. Frequently, however, the plant models do not match exactly the types being used in a given project and where they do, may not be able to provide the required information. To address such limitations research has been undertaken into alternative approaches. The aim of such research is to provide a modeling approach that is widely applicable and offers efficient code management and data sharing. Primitive Part (PP) modeling is one such effort, which employs generic, process-based elements to attain modeling flexibility. Recent efforts have been on the development of data structure and graphics that facilitates PP auto-connection via computer interface. This paper describes the approach using an example application and its suggested role within an integrative simulation environment

    A Model of Regulatory Burden in Technology Diffusion: The Case of Plant-Derived Vaccines.

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    Plant-derived vaccines may soon displace conventional vaccines. Assuming there are no major technological barriers undermining the feasibility of this innovative technology, it is worthwhile to generate quantitative models of regulatory burden of producing and diffusing plant-derived vaccines in industrialized and developing countries. A dynamic simulation model of technology diffusion—and the data to populate it—has been generated for studying regulatory barriers in the diffusion of plant-derived vaccines. The role of regulatory burden is evaluated for a variety of scenarios in which plant-derived vaccines are produced and diffused. This model relates the innovative and conventional vaccine technologies and the effects of the impact of the uptake of the innovative technology on mortality and morbidity. This case study demonstrates how dynamic simulation models can be used to assess the long-term potential impact of novel technologies in terms of a variety of socio-economic indicators.dynamic simulation model; plant-derived vaccines; regulatory burden; technology transfer; vaccines;

    Bioregenerative life support

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    Bioregenerative life support systems utilize plant growth for food, water, and atmosphere revitalization. Simulation studies of a simplified model are presented that suggest survivability in the face of partial plant growth chamber failure. Simulation studies demonstrate the potential for a bioregenerative life support system on an extended mission. In addition to robustness and survivability in terms of the food supply, the plant growth chamber produces exactly the right amount of oxygen for the crew's metabolic needs. The amount of water taken up by the plants during food production is balanced by the crew's metabolic water production

    Bio-ethanol Production from Wheat in the Winter Rainfall Region of South Africa: A Quantitative Risk Analysis

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    Contrary to developments in other parts of the world, South Africa has not developed a bio-ethanol industry. The objective was to quantify the risks and economic viability of a wheat based bio-ethanol plant in the winter rainfall region of South Africa. Monte Carlo simulation of a bio-ethanol plant was used to quantify the risk that investors will likely face. Under the Base scenario a 103 million liter bio-ethanol plant would not offer a reasonable chance of being economically viable. Alternative price enhancing policies were analyzed to determine policy changes needed to make a bio-ethanol plant economically viable in the region.biofuels, ethanol, risk analysis, simulation, economic viability, Simetar, SERF, Crop Production/Industries, Resource /Energy Economics and Policy,

    Estimating solar radiation for plant simulation models

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    Five algorithms producing daily solar radiation surrogates using daily temperatures and rainfall were evaluated using measured solar radiation data for seven U.S. locations. The algorithms were compared both in terms of accuracy of daily solar radiation estimates and terms of response when used in a plant growth simulation model (CERES-wheat). Requirements for accuracy of solar radiation for plant growth simulation models are discussed. One algorithm is recommended as being best suited for use in these models when neither measured nor satellite estimated solar radiation values are available

    Development and Experimental Validation of a Dynamic Model for a Fresnel Solar Collector

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    this paper presents a lumped parameter dynamic model of a Fresnel collector field of a solar refrigeration plant. The plant is located in the Escuela Superior de Ingenieros of the University of Seville. The dynamic model parameter model developed can be used as a control model or as a simulation tool to test controllers. The lumped parameters have been determined by using real data from the plant in different operating conditions. The model has been validated against a data validation set obtained from the plant. The model has shown to reproduce the system behavior with a good compromise in accuracy and model complexity
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