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2<br />

The classrooms are sometime shared between faculties. Each faculty needs its own<br />

timetable <strong>for</strong> its own resources. As a result, many problems still exist in the course<br />

scheduling related to the shared resources.<br />

Course scheduling itself contains a large number of conflicts and needs a large<br />

amount of processing time. For course scheduling in the <strong>multi</strong>ple faculties, the data<br />

used <strong>for</strong> scheduling also needs to be collected and shared across the faculties. This<br />

study proposes a hybrid centralized and de-centralized approach, <strong>genetic</strong> <strong>algorithm</strong>,<br />

and grid computing environment to the course scheduling problem in <strong>multi</strong>ple faculty<br />

universities. The proposed approach and the <strong>genetic</strong> <strong>algorithm</strong> are used to solve the<br />

NP hard problems. In addition, the grid computing environment is used as<br />

infrastructure <strong>for</strong> distributed and parallel computing.<br />

1.1.2 Background<br />

The <strong>genetic</strong> <strong>algorithm</strong> (GA) is a global search optimization <strong>algorithm</strong> using<br />

parallel points. While searching <strong>for</strong> solutions, the GA uses a fitness function that<br />

affects the direction of the search [6]. The GA evaluates the population by using<br />

<strong>genetic</strong> operators such as selection, crossover, and mutation. The outline of the basic<br />

GA is presented in Figure 1-2.<br />

1 [Start] Generate random population of n chromosomes.<br />

2 [Fitness] Evaluate the fitness f(x) of each chromosome x in the population.<br />

3 [New population] Create a new population by repeating following steps until the new population is<br />

complete.<br />

3.1 [Selection] Select two parent chromosomes from a population according to their fitness (the better<br />

fitness, the bigger chance to be selected).<br />

3.2 [Crossover] With a crossover rate cross over the parents to <strong>for</strong>m new offspring (children). If no<br />

crossover was per<strong>for</strong>med, offspring is the exact copy of parents.<br />

3.3 [Mutation] With a mutation rate mutate new offspring at each locus (position in chromosome).<br />

3.4 [Accepting] Place new offspring in the new population.<br />

4 [Replace] Use new generated population <strong>for</strong> a further run of the <strong>algorithm</strong>.<br />

5 [Test] If the end condition is satisfied, stop, and return the best solution in current population.<br />

6 [Loop] Go to step 2.<br />

FIGURE 1-2 Outline of the basic <strong>genetic</strong> <strong>algorithm</strong> [6]

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