We live in a world of systems driven by cause and affect. Those systems include financial, production, inventory, biological, chemical, thermodynamic or workflow. Systems can be modeled as nodes representing system variables and connecting lines representing causal effects. The changing value of one variable can cause another to increase or decrease as described by equations. Understanding how ...

1. Introduction Systems approach has been used by engineers since the 1950's for the study of complex and dynamic processes but their use by scientists working in biological fields is relatively recent. A system is defined as any well delineated part of reality which may contain a number of interrelated elements forming the systems structure. These functioning components interact in various way...

©1999 No part of this book may be reproduced in any form by print, photoprint, microfilm or any other means without the prior written permission from the publisher. A publication in coöperation with the Dutch researchgroups SIMULATION and COMPLEX SOCIETAL PROBLEMS of the NOSMO (Dutch Research group on Methodology) Validation of simulation models in the social sciences Cor van Dijkum and Etzel v...

In this paper, numerical simulation of FRP composite cylinder tubes progressive crushing processes is conducted using LS-Dyna. Details on the numerical modeling strategy are given and discussed. It is found that triggers introduced in the numerical simulation can effectively model the bevel trigger at the end of the tubular specimens. It is also found that two-layer finite element model based o...

One of the most important methods employed to measure the market risk is value at risk calculation method. In this study, the value at risk of banks listed on the Tehran Stock Exchange and Over-the-counter (OTC) are calculated using parametric model, Monte Carlo simulation, historical simulation and Two-Sided Power (TSP) Distribution. The sample includes all listed banks in Iran. The results sh...

Accurate simulation models of social networks enable over time prediction, statistical testing of hypothesis about social groups, and enables researchers to develop more informed hypotheses for human experimentation, by evaluating them and reasoning about them using simulation. Several methods for simulating social network behavior are compared. The multi-agent simulation Construct is shown to ...

This paper provides a framework for discussing the empirical validation of computer simulation models of market phenomena. It considers first a simulation model of a market of competing coffee brands to ask some questions about the purposes and practices of simulation modeling. It defines functional complexity and derives measures of this for Schelling’s Segregation model. It refers to the Ener...

In this study, turbulent compressible gas flow in a rectangular micro-channel is numerically investigated. The gas flow assumed to be in the subsonic regime up to Mach number about 0.7. Five low and high Reynolds number RANS turbulence models are used for modeling the turbulent flow. Two types of mesh are generated depending on the employed turbulence model. The computations are performed for R...

Simulation of a business process is often used to visualize its behaviour, to identify problems and to improve its performance. It requires the design of a simulation model, a detailed model of the processes, the resources and the variables to be monitored. Here we investigate how the development of such a model can be facilitated by using a language-action model of the business process as a ba...

most of river engineering problems are complicated and need to be analyzed by three dimensional models of flow and sediment transport. considering the fact that computers and numerical methods with great ability of flow and sediment transport simulation are developing quickly, using numerical modeling by engineers is inevitable. nevertheless, before application, numerical models need to be veri...