EAI Endorsed Transactions on Context-aware Systems and Applications, 2017
Modeling in ecol ogy or epidemiol ogy gener all y opposes tw o classes of models, Equa tion Based... more Modeling in ecol ogy or epidemiol ogy gener all y opposes tw o classes of models, Equa tion Based Models and Agent Based Models. Mathema tical models all ow predicting the long-term dynamics of the studied systems. How ev er, the variability betw een individ uals is di fficul t to represen t, wha t makes these more suitable models for larg e and homog eneous popula tions. Mul ti-ag ent models all ow represen ting the attributes and beha vior of each individ ual and theref ore provide a grea ter lev el of detail. In return, these systems are more di fficul t to anal yze. These approaches have often been compared, but rarel y used sim ul taneousl y. We propose a hybrid approach to couple equa tions models and ag ent-based models, as well as its implemen tation on the modeling pla tf orm Gama . We focus on the represen tation of a classical theoretical epidemiol ogical model (SIR model) and we ill ustr ate the construction of a class of models based on it.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2015
Coupling models is becoming more and more important in the fields where modeling relies on interd... more Coupling models is becoming more and more important in the fields where modeling relies on interdisciplinary collaboration. This in particular the case in modeling complex systems which often require to either integrate different models at different spatial and temporal scales or to compare their outcomes. The goal of this research is to develop an original agent-based approach to support the coupling heterogeneous models. The architecture that we have designed is implemented in the GAMA modeling and simulation platform . The benefits of our approach is to support coupling and combining various models of heterogeneous types (agent-based, equation-based, cellular automata ) in a flexible and explicit way. It also support the dynamic execution of the models which are supposed to be combined during experiments. We illustrate its use and powerfulness to solve existing problems of coupling between an agent-based model, equation-based model and GIS based model. The outcomes of the simulation of these three models show results compatible with the data observed in reality and demonstrate the interest of our approach for building large, multi-disciplinary models.
We validate the RBAC ANSI 2012 standard using the B method. Numerous problems are identified: log... more We validate the RBAC ANSI 2012 standard using the B method. Numerous problems are identified: logical errors, inconsistencies, ambiguities, typing errors, missing preconditions, invariant violation, inappropriate specification notation. A clean version of the standard written in the B notation is proposed. We argue that the ad hoc mathematical notation used in the standard is inappropriate and we propose that a more methodological and tool-supported approach must definitely be used for writing standards, in order to avoid the issues identified in the paper. Human reviewing is insufficient to produce error-free international standards.
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Papers by Nghi Huỳnh