G.: Specification of Discrete Event Models for Fire Spreading (original) (raw)

Discrete-event modelling of fire spreading

International Journal of Systems Science, 2008

We deal here with the application of discrete-event System Specification (DEVS) formalism to implement a semi-physical fire spread model. Currently, models from physics finely representing forest fires are not efficient and still under development. If current softwares are devoted to the simulation of simple models of fire spread, nowadays there is no environment allowing us to model and simulate complex physical models of fire spread. Simulation models of such a type of models require being easily designed, modified and efficient in terms of execution time. DEVS formalism can be used to deal with these problems. This formalism enables the association of object-oriented hierarchical modelling with discrete-event techniques. Object-oriented hierarchical programming facilitates construction, maintenance and reusability of the simulation model. Discrete-events reduce the calculation domain to the active cells of the propagation domain (the heated ones).

DEVS-FIRE: design and application of formal discrete event wildfire spread and suppression models

SIMULATION, 2011

DEVS-FIRE is a discrete event system specification (DEVS) model for simulating wildfire spread and suppression. It employs a cellular space model to simulate fire spread and agent models that interact with the cellular space to simulate fire suppression with realistic tactics. The complex interplay among forest cells and agents calls for formal treatment of the fire spread and fire suppression models to verify the correctness of DEVS-FIRE. This paper gives formal design specifications of fire spread and suppression agent models used in DEVS-FIRE and applies DEVS-FIRE to both artificially generated and real topography, fuels and weather data for a study area located in the US state of Texas. The paper also develops a new method, called pre_Schedule, for scheduling ignition events of forest cells more efficiently than the original onTime_Schedule event scheduling method used in DEVS-FIRE. Simulation results show the performance improvement of the new method, and demonstrate the utilit...

Modeling of Firefighting Operations through Discrete Event Simulation

International Journal of Computer Theory and Engineering, 2013

This paper reports the results of applying discrete event simulation on firefighting operations in the State of Kuwait. The objective was reduce response times to reach fires in all districts to below five minutes. The Simulation of output runs were analyzed using ANOVA. The results were validated at 95% confidence level. Simulation turned to be an excellent tool for testing a major change without disturbing firefighting operations. 

Modelling and simulation of ecological propagation processes: application to fire spread

Environmental Modelling & Software, 2005

An important class of ecological problems concerns propagation processes. In ecological modelling, these phenomena generally occur on large scales and are generally difficult to simulate efficiently because of the number of entities. Studies of this kind of phenomena lack genericity and reusability because they are often presented from the point of view of a single domain expert. Simulations made by domain experts seem to lack genericity for computer science specialists and simulations developed by computer science specialists seem not to grasp the terminology and problems of the domain experts. We propose here a general object-oriented framework for modelling and simulation of propagation processes. Object-oriented techniques help in developing generic and reusable models. From modelling to simulation, the Unified Modelling Language (UML) provides a common means of communication between computer science specialists and domain experts. The Model Driven Architecture (MDA) is used to improve object-oriented methodology. Simulation optimisations are defined for discrete time models of propagation. The approach is applied to the modelling and simulation of fire spread. Starting from wasteland fire problems, specification levels are used to gradually specify a fire spread simulator. Each level of the study is specified in UML and thus can be reused in another wasteland fire problem.

A suggested model for mass fire spread

Sustainable and Resilient Infrastructure, 2018

Fire following earthquake possesses significant risk of damages to life and property in urban areas. Mitigation and planning can reduce the level of risk associated with post-earthquake fire spread. This paper presents the details of a model that can be used to simulate mass urban fire spread based on the building material. The mechanisms of fire spread both within a building and building to building have been considered. For modelling building-to-building fire spread, the effects of direct flame impingement, heat transfer by convection and radiation, and flaming brands have been included in the model. A cellular automata scheme of modelling was employed for the construction of model. The model was implemented using a free-source computer programming framework which allows integration of building information data in geographic information system and mathematical formulation of fire spread mechanics. The results of the model have been compared with the existing data of mass urban conflagration. The employed algorithm was found to be stable which eliminates the need of large number of iterations to obtain reliable predictions. The results of the model correlated well with the existing data of fire-related damages and extent of fire spread available in the literature.

Towards validation of DEVS-FIRE wildfire simulation model

Proceedings of the 2008 Spring simulation …, 2008

DEVS-FIRE is a model for discrete event simulation of wildfire spread, where fire spread is modeled as a contagion process in a cellular space of forest cells. In this paper, DEVS-FIRE is validated using FARSITE, a widely used fire spread model. Both graphical and statistical approaches are used and the results show that the output of DEVS-FIRE is comparable to that of FARSITE under a wide range of input conditions.

A probabilistic model of fire spread with time effects

Fire Safety Journal, 1994

The paper outlines the principal elements of a probabilistic model that analyses the spread of fire in multi-compartment buildings with respect to time. The analysis uses a graph theoretic network and an event hierarchy to determine the probability of fire spreading to different locations. The probability of fire spreading between compartments is based on a comparison of the probability density functions of the expected fire resistance and the fire severity: failure being the condition that severity exceeds resistance. The model is designed as a comparative tool to compare the performance of different fire safety strategies by calculating a 'cost index' for each design, based on the probable extent of fire damage in the building. The analysis gives attention to the compatibility of fire resistance and fire severity, and their conversion in real time parameters. AB AF AT Aw NOTATION Total floor area of the building (m 2) Floor area of the fire compartment (m 2) Internal surface area, excluding floors (m:) Ventilation area (m 2) 367 Ignition time for upper compartment in window fire spread Cost of passive fire protection measures, as a ratio of the capital value of the building Discount factor = (1-e-V~)/(e v-1) Design life of building (years) Repair costs, as a ratio of the capital value of the building Density of ambient air (kg/m 3) Cnq,, is taken as 1.2 kJ/m 3 K

DEVS-FIRE: Towards an Integrated Simulation Environment for Surface Wildfire Spread and Containment

SIMULATION, 2008

Simulating wildfire spread and containment remains a challenging problem due to the complexity of fire behavior. In this paper, the authors present an integrated simulation environment for surface wildfire spread and containment called DEVS-FIRE. DEVS-FIRE is based on the discrete event system specification (DEVS) and uses a cellular space model for simulating wildfire spread and agent models for simulating wildfire containment. The cellular space model incorporates real spatial fuels data, terrain data and temporal weather data into the prediction of wildfire behavior across both time and space. DEVS-FIRE is designed to be integrated with stochastic optimization models that use the scenario results from the simulation to determine an optimal mix of firefighting resources to dispatch to a wildfire. Preliminary computational experiments with fuel, terrain and weather data for a real forest demonstrate the viability of the integrated simulation environment for wildfire spread and containment.

Two-Dimensional Fire Spread Decomposition in Cellular DEVS Models

Wildflres and their associated destruction have high- lighted the need for real-time simulation systems for accurately predicting flre spread. Such systems would assist flre managers in their efiorts to efiectively con- tain potentially catastrophic flres. Modeling and sim- ulation of forest flre spread using the cellular discrete event approach is based on dividing the forest into small areas called cells. Fire spread is then modeled as a contagion process between cells where forward flre spread across each cell is computed using a math- ematical flre spread model. Rothermel's mathemat- ical flre spread model allows for computing a one- dimensional maximum forward spread rate and di- rection. Fire spread in all other directions is inferred from this forward spread rate. If this inference is not correctly abstracted it can lead to distortion of flre shapes and incorrect simulation results. This paper proposes a new two-dimensional flre spread decom- position scheme for cellular...