gelmisb / cellularautomata

Simulating the Spread of the Ebola Virus using a Cellular Automaton Framework in a Parallel Computing Environment

Introduction

The Ebola virus is one of the most deadly viruses known to man, its high mortality rate and high transmission rate make the virus difficult to contain. In recent years the world has been witness to a severe outbreak of the virus in Africa. At one point many countries had been put on high alert in an attempt to stop the spread of the virus outside of Africa.

Cellular automata

Cellular automaton consist of grid of cells (or an array), which changes through time due to rules that are pre-defined, as to its cell neighbours before the execution. Each cell will represent a person and their state of health (healthy, infected, recovered or dead). In a program designed to display the information in a graphical format colour will represent the state each person is currently in i.e. healthy, infected etc. In this case a two-dimensional automaton will be used in order to get data from a cells neighbour (Wolfram, 1994)[Figure 1]. Pfeifer (2008) uses the cellular automaton framework to design spread of infectious disease in the state Tyrol in Austria. Instead of programming the cellular automaton in C he uses Java, but still represents the data on a map. The set of rules that are going to be implemented on the single core program will be very narrow in order to not overcomplicate the task. After being successfully run on of the single core program a parallel version of this program will be implemented.

Our Work

The workload has been divided up and each member of the group has been given work best suited to them. Initially members have been allocated work such as implementing a C program which will create the cellular automaton and populate it with people in each cell. Once complete and functional the rules for the cellular automaton will be implemented, rules such as virus infectivity, mortality rate and probability of recovery. Another task was to implement a program which could render the data on screen in some sort of graphical interface. Java was the language which was chosen for this as it is a programming language all group members are familiar with. This program would read in files created by the C program, once read into the program data from these files would be saved to an array for use in a double for loop which would iterate through each cell of the automaton. Depending on the value saved to that position each cell would be colour accordingly, green for alive, yellow for infected, red for dead and finally black for recovered. The cells were displayed as pixels on screen inside a JPanel of a JFrame. Research and documentation was another task, it involved writing up of reports, research, keeping a log of references and creation of a power point presentation. Research involved obtaining information on the Ebola virus in order for the program to set the right variables within the cellular automaton. Information such as infection rate, mortality rate and recovery rate were all taken note of and then integrated into the program.