Search results for "Simulation modeling"
showing 10 items of 41 documents
A heuristic for problem formalization in agent based simulation studies
2015
Agent Based Modeling and Simulation (ABMS) is considered an effective approach for conducting simulation studies in many fields. In order to develop high quality simulation models, methodological approaches are demanded. In such direction we are moving by proposing a heuristic for the formalization of agent based simulation problems. The proposed heuristic is based on some guidelines developed for identifying the main elements of the problem domain description by analysing verbs and their common taxonomy in grammar.
Biproportional methods of structural change analysis: A typological survey
2004
International audience; Analysts often are interested in learning how much an exchange system has changed over time or how two different exchange systems differ. Identifying structural difference in exchange matrices can be performed using either 'directed' or 'undirected' methods. Directed methods are based on the computation and comparison of column- or row-normalizations of the matrices. The choice of row or column for the normalization implies a specific direction of the exchanges, so that the column-wise normalized results should not be compared to the row-wise normalized results. In this category fall the simple comparison of coefficient matrices and the causative method. Undirected m…
Fitting particle size distribution models to data from Burundian soils for the BEST procedure and other purposes
2009
Testing the Beerkan Estimation of Soil Transfer (BEST) soil particle size distribution (PSD) model is necessary to evaluate the applicability of the BEST procedure for characterising soil hydraulics. In this investigation, the fitting performance of the BEST PSD model was tested using a database of 114 Burundian soils with 14 measured particle size fractions for each soil sample, and also by considering a reduced number of measured particle size fractions for a sample. The fitting performance of the model developed by Fredlund et al. (2000) (FR model) was also considered for comparative purposes. On average, the BEST model yielded satisfactory results (i.e., mean relative error, E r ¯ = 3.9…
Proposal of a neuro-fuzzy model of a WWW server
2005
This paper presents the ways of designing simulation models of Web servers. At the beginning queuing network models are introduced, those models are generally known and often used in the initial phase of research on particular technical solutions. Next, an entirely new approach to the issue discussed is presented - neuro-fuzzy models, thanks to which, it is possible to automate the process of designing simulation models. The results of comparative tests of these two models are presented. Based on these results it can be concluded that neuro-fuzzy models are accurate and can be used in simulation research.
Multivariate Statistical Analysis for Water Demand Modeling
2014
The actual level of water demand is the driving force behind the hydraulic dynamics in water distribution systems. Consequently, it is crucial to estimate it as accurately as possible in order to result in reliable simulation models. In this paper, a copula-based multivariate analysis has been proposed and used for demand prediction for given return period. The analysis is applied to water consumption data collected in the water distribution network of Palermo (Italy). The approach showed to produce consisted demand patterns and to be a powerful tool to be coupled with water distribution network models for design or analysis problems. (C) 2014 Published by Elsevier Ltd.
Sensitivity of Regional Water Supply Systems Models to the Level of Skeletonization – A Case Study from Apulia, Italy
2015
AbstractSimulation models supported by state-of-the-art software packages are nowadays available to explore operation rules of regional water supply systems or to select structural alternatives for improving long-term service performances.Given the, sometimes high, complexity of these systems, model calibration can become a lengthy procedure and many runs are necessary before obtaining convincing results. However, even after calibration, depending on system's complexity and the number of time steps investigated, a single run can take up to several minutes, even on state-of-the-art computers, so that simulation time can become a true bottleneck if such models are to be coupled with metaheuri…
Considerations for Using Domain-Specific Modeling in the Analysis Phase of Software Development Process
2002
Recent studies claim that domain-specific modeling may highly increase development productivity in specific well-defined domains. Domain-specific modeling is most often used only in the design phase of software development process, while general-purpose modeling techniques are used in the other phases. Integrating general-purpose modeling techniques with domain-specific modeling might be problematic, which is why in this paper we consider if it is feasible to extend domain-specific modeling to cover analysis phase activities in addition to design phase activities. Essentially, we discuss the different activities in analysis phase and consider whether or not domain-specific techniques can be…
Biproportional Method for Analysing Interindustry Dynamics: the case of France
1990
Two elements are being presented in this paper: (1) A new and original method for analysing matrix dynamics, called the synthetical biproportional projector method (SBP), which can be used to project input–output tables and compare one with another. (2) Some results for France for the important period 1970–85. The paper starts with the observation that no systematic study of the change in the French productive structure as displayed In the input–output tables (tableaux entries-sorties in France) has ever been made. This is unfortunate, since a complete series of data is now available concerning a key period of the French economic evolution including the petroleum crisis, European integratio…
Urban Traffic Analysis through an UAV
2014
Abstract In order to realize a precise and accurate traffic study, a method to evaluate the real traffic flow conditions in urban areas based on videos acquired by an UAV, Unmanned Aerial Vehicle, is proposed. In this way it does not require additional equipment to earth and, not being invasive, does not influence the driver behavior. This paper presents the results obtained in terms of vehicular traffic flow along a way in the city of Palermo. The results have been compared to experiments using macroscopic simulation models and the eventually differences have been discussed.
Common and Domain-specific Metamodel Elements for Problem Description in Simulation Problems
2014
It is well known that the multi-agent system paradigm is well suited for modelling and developing simulations of complex systems belonging to several application domains. Simulation study aims at developing simulation models useful for representing, studying and analyzing entities and their behavior in a system according to specific purposes. With our work we are trying to understand what are the right elements to be considered and included in the description of a simulation problem. In order to root our resulting metamodel in the state of the art of multi-agent simulations we started from the study of twelve papers dealing with four different application domains: Crowd Dynamics, Traffic an…