Discrete event front tracking simulator of a physical fire spread model

International audienceSimulation of moving interfaces, like a fire front usually requires the resolution of a large scale and detailed domain. Such computing involves the use of supercomputers to process the large amount of data and calculations. This limitation is mainly due to the fact that large scale of space and time is usually split into nodes, cells or matrices, and the solving methods often require small time steps. This paper presents a novel method that enables the simulation of large scale/high resolution systems by focusing on the interface. Unlike the conventional explicit and implicit integration schemes, it is based on the discrete-event approach, which describes time advance in terms of increments of physical quantities rather than discrete time stepping. Space as well is not split into discrete nodes or cells, but we use polygons with real coordinates. The system is described by the behaviour of its interface, and evolves by computing collision events of this interface in the simulation. As this simulation technique is suited for a class of models that can explicitly provide rate of spread for a given configuration, we developed a specific radiation based propagation model of physical wildland fire. Simulations of a real large scale fire performed with an implementation of our method provide very interesting results in less than 30 seconds with a 3 metres resolution with current personal computers

Simulation in the Cloud Using Handheld Devices

International audienceIn recent years, numerous applications have been deployed into mobile devices. However, until now, there have been no attempts to run simulations on handheld devices. We want investigate different architectures for running and managing simulations on handheld devices, and putting the simulation services in the Cloud. We propose a hybrid simulation and visualization approach, where a dedicated mobile application is running on the client side and the RISE simulation server is hosted in the Cloud. In particular, with our prototype, we explore the remote management of a simulation tool using a dedicated native application running on an Android Smartphone, and showing the evolution of a simulation model for a forest fire spread, mashing-up the generated graphics with online GIS services

Prédiction structurale de biomolécules à l'aide d'une construction d'automates cellulaires simulant la dynamique moléculaire

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

TerraME HPA : uma arquitetura de alto desempenho para simula??o paralela de modelos ambientais.

Programa de P?s-Gradua??o em Ci?ncia da Computa??o. Departamento de Ci?ncia da Computa??o, Instituto de Ci?ncias Exatas e Biol?gicas, Universidade Federal de Ouro Preto.O cont?nuo aumento da complexidade dos modelos ambientais pode demandar o uso de m?ltiplos paradigmas de modelagem para descrever as intera??es entre sociedade e natureza. Al?m disto, o crescente volume de dados e de c?lculos utilizados nestes modelos exige que as simula??es tirem m?ximo proveito do paralelismo de hardware existente em arquiteturas multiprocessador e multicomputador. Neste contexto, este trabalho apresenta e avalia uma abordagem para o desenvolvimento e simula??o de modelos ambientais concorrentes e baseados em m?ltiplos paradigmas. O objetivo principal ? gerar simula??es escal?veis e o objetivo secund?rio ? produzir modelos concorrentes flex?veis. Isto ?, modelos que possam ser facilmente verificados e evolu?dos. A abordagem proposta consiste na tradu??o automatizada do c?digo anotado do modelo sequencial em um c?digo paralelo pass?vel de ser executado por uma m?quina virtual, cujo modelo de concorr?ncia e mecanismo para balanceamento de carga independam dos paradigmas de modelagem utilizados. Para implementar esta abordagem, a plataforma de modelagem e simula??o ambiental TerraME foi estendida de duas formas, dando origem a plataforma TerraME HPA (High Perfomance Architecture). Primeiro, a ela foi adicionada um pr?-processador que traduz o c?digo anotado dos modelos em programas concorrentes na linguagem de programa??o Lua. Depois, o interpretador Lua originalmente distribu?do com o TerraME foi substitu?do pelo interpretador MOOM, tamb?m desenvolvido neste trabalho. O MOOM utiliza o mecanismo de bag-of-tasks para executar fun??es Lua em paralelo. Desta forma, ele reduz o n?vel de concorr?ncia programado pelos modeladores e distribui a carga de trabalho das simula??es entre os processadores dispon?veis em hardware. Finalmente, v?rios benchmarks selecionados na literatura foram utilizados para avaliar o desempenho e a escalabilidade de diferentes plataformas de programa??o concorrente na linguagem Lua (ALua, Lane, Luaproc e MOOM) e de diferentes plataformas destinadas ao desenvolvimento simula??es ambientais de alto desempenho: TerraME HPA, Repast HPC e D-MASON vers?es 1.5 e 2.1. Os resultados evidenciam que, quando comparados aos trabalhos correlatos, o interpretador MOOM e a plataforma TerraME HPA apresentaram uma escalabilidade muito boa em todos os cen?rios avaliados. As aplica??es Lua resultantes desta abordagem s?o flex?veis, pois ao ignorar as anota??es, os interpretadores permitem que elas sejam verificadas e evolu?das sequencialmente.The continuous increase in the complexity of environmental models can require the use of multiple modeling paradigms to describe the interactions between society and nature. Moreover, the growing volume of data and calculations used in these models requires that the simulations take full advantage of existing hardware parallelism on multiprocessor and multicomputer architectures. In this context, this paper presents and evaluates an approach to the development and simulation of concurrent environmental models based on multiple paradigms. The main objective is to generate scalable simulations and the secondary objective is to produce flexible concurrent models. That is, models which can be easily verified and extended. The proposed approach consists in performing the automated translation of the annotated code from the sequential model into a parallel code that can be executed by a virtual machine, which concurrency model and mechanism for load balancing are independent of the modeling paradigms used in the models. To implement this approach, the modeling and simulation platform TerraME was extended in two ways, giving rise to the TerraME HPA (High Perfomance Architecture) platform. First, it was added a pre-processor that translates the annotated codes into concurrent programs on the Lua programming language. Then, the Lua interpreter originally distributed with TerraME was replaced by the interpreter MOOM, also developed in this work. The MOOM uses the bag-of-tasks mechanism to run Lua functions in parallel. Thus, it reduces the level of concurrency programmed by modelers and distributes the simulation workload among the processors available in hardware. Finally, a number of benchmarks selected from literature were used to evaluate the performance and scalability of different platforms for concurrent programming in Lua (ALUA, Lane, Luaproc, and MOOM) and of different platforms for the development of high performance environmental simulations: TerraME HPA, Repast HPC and D-MASON versions 1.5 and 2.1. The results show that, when compared to related work, the interpreter MOOM and the platform TerraME HPA presents very good scalability in all evaluated scenario. The Lua applications resulting from this approach are flexible, because ignoring the annotations inserted in their codes, interpreters allow them to be verified and evolved sequentially

Conceptual Modeling of a Quantum Key Distribution Simulation Framework Using the Discrete Event System Specification

Quantum Key Distribution (QKD) is a revolutionary security technology that exploits the laws of quantum mechanics to achieve information-theoretical secure key exchange. QKD is suitable for use in applications that require high security such as those found in certain commercial, governmental, and military domains. As QKD is a new technology, there is a need to develop a robust quantum communication modeling and simulation framework to support the analysis of QKD systems. This dissertation presents conceptual modeling QKD system components using the Discrete Event System Specification (DEVS) formalism to assure the component models are provably composable and exhibit temporal behavior independent of the simulation environment. These attributes enable users to assemble and simulate any collection of compatible components to represent QKD system architectures. The developed models demonstrate closure under coupling and exhibit behavior suitable for the intended analytic purpose, thus improving the validity of the simulation. This research contributes to the validity of the QKD simulation, increasing developer and user confidence in the correctness of the models and providing a composable, canonical basis for performance analysis efforts. The research supports the efficient modeling, simulation, and analysis of QKD systems when evaluating existing systems or developing next generation QKD cryptographic systems