Search results for "Simulation modeling"
showing 10 items of 41 documents
Simulation-based Evacuation Planning for Urban Areas
2021
Evacuation planning is a critical task in disaster management. Especially in situations such as natural disasters or terrorist attacks, large crowds need to move away from danger and reach designated safe zones. For this purpose, various approaches that efficiently compute evacuation plans in urban areas have been proposed. To evaluate the computed plans, previous works employ heuristics that can only roughly estimate the egress time of each plan. Intuitively, a much better approach is to estimate the egress time via simulation. However, designing a simulation model is usually a time-consuming task and, what is more, this model can only be used to evaluate evacuation plans for a specific ar…
The Asynchronous Leontief Model
1992
International audience; The traditional dynamic Leontief model is synchronous: every vertex acts simultaneously. A model with delays of action has been proposed, but it still remains synchronous. In this paper we propose an asynchronous version of the model that allows realistic computations. We fiurnish an algorithm and a program.
Simulation Modeling Using Agents For Mass Customization
2004
Reconfigurable enterprises and production networks — virtual structures of manufacturing enterprises that coalesce and vanish in response to a dynamic marketplace — are one of the main enabler paradigm for mass customizable production. The design and coordination of production networks to changing market dynamics are challenging tasks. Simulation provides the ability to develop prototypes of such complex systems cost effectively and in shorter duration. This Chapter describes how simulation can be utilized in conjunction with multi agent system techniques to develop realistic prototypes of complex decision support systems for the design of coordination strategies in large-scale mass customi…
A carbon budget model to predict branch carbohydrate deficiencies as a function of water stress and crop load in pistachio (Pistacia veraL.)
2018
The effect of irrigation and crop load on alternate bearing was studied in pistachio tree using a “branch carbon budget model” developed to calculate branch carbohydrate balance. Experiences were conducted in Sicily (37°26’N, 14°03’E, 360 m a.s.l.) on female trees of ‘Bianca’. Two treatments were applied: rainfed (T0) and 100 mm of irrigation (T100). At 29, 44, 65, 86, 103 and 121 DAFB, on one fully expanded leaf selected on three trees per treatment, were monitored leaf gas exchanges. At 15 days interval, three branches treatment-1 were excised and, in the lab, the following parameters were measured: total photosynthetically active leaf surface; number of leaves, fruits, shoot fresh weight…
Simulation models in eGovernment using system dynamics: A literature survey
2016
System Dynamics (SD) is a method to build simulation models using computers, to study the behaviour of systems, and apply what-if scenarios aiming at achieving optimal policy design. To have an overview of the current state-of-the-art of SD use in the eGovernment field; we have surveyed related literature. Our main goal is to uncover the possibilities for future research by clarifying the shortages. The identified literature is not very large. In most of the literature, SD models use was limited to SD practitioners. We discovered low usage of Group Model Building and workshops despite their usefulness in involving non-SD practitioners in the model building process. Additionally, there is a …
A multidisciplinary approach to the study of cultural heritage environments: Experience at the Palatina Library in Parma
2015
The aim of this paper is to describe a multidisciplinary approach including biological and particle monitoring, and microclimate analysis associated with the application of the Computational Fluid Dynamic (CFD). This approach was applied at the Palatina historical library in Parma. Monitoring was performed both in July and in December, in the absence of visitors and operators. Air microbial monitoring was performed with active and passive methods. Airborne particles with a diameter of ≥0.3, ≥0.5, ≥1 and ≥5 μm/m3, were counted by a laser particle counter. The surface contamination of shelves and manuscripts was assessed with nitrocellulose membranes. A spore trap sampler was used to identify…
Understanding the shortcomings of commodity-based technology in input-output models: an economic-circuit approach
2004
International audience; The Make-Use Model serves as a basis for most national accounting systems as the System of National Accounts (SNA) and is acknowledged as the most suitable model for interregional analysis. Two hypotheses are traditionally made featuring either industry-based technologies (IBT) or commodity-based technologies (CBT). While industry-based technologies can be easily interpreted in terms of a demand-driven economic circuit, it will be shown that: (1) commodity-based technologies cannot be interpreted as a demand-driven economic circuit because this involves computing the inverse of a matrix (the matrix of industry output proportions), which is either impossible or genera…
Using Hydrus 2-D Simulation model to evaluate wetted soil volume in subsurface drip irrigation systems.
2007
Drip irrigation is considered one of the most efficient irrigation systems. Alternatively to the traditional drip irrigation systems, laterals can be installed below the soil surface. Realizing the subsurface drip irrigation (SDI), which recently has been increasing in use as a consequence of advances in plastics technology, making SDI equipment more affordable and long lasting. Due to its potential high efficiency SDI may produce benefits, especially in places where water is a limited source. As the use of SDI is relatively new, a better understanding of the infiltration process around a buried point source can contribute to increased water use efficiency and consequently the success of dr…