Research Article
A Fast and Efficient Estimation of the Parameters of a Model of Accident Frequencies via an MM Algorithm
Table 1
Results for Scenario
1 (
and
). Values in brackets are standard deviations.
| | MM | SqS3 | NR | BFGS |
| | | 0.826 (0.176) | 0.826 (0.176) | 0.826 (0.176) | 0.824 (0.174) | | 0.649 (0.068) | 0.649 (0.068) | 0.649 (0.068) | 0.648 (0.068) | | 0.351 (0.068) | 0.351 (0.068) | 0.351 (0.068) | 0.352 (0.068) | | 0.247 (0.062) | 0.247 (0.062) | 0.247 (0.062) | 0.246 (0.061) | | 0.753 (0.062) | 0.753 (0.062) | 0.753 (0.062) | 0.754 (0.061) | Convergence proportion (%) | 100 | 100 | 99.5 | 76.1 | Iterations | 24 (4.1) | 7 (1) | 5.5 (1.5) | 13 (0.1) | CPU time (secs) | 0.004 | 0.002 | 0.002 | 0.087 | Time ratio | 1.00 | 0.51 | 0.62 | 23.63 | Log-likelihood | -126.66 | -126.66 | -126.67 | -126.71 | MSE | | | | |
| | | 0.800 (0.016) | 0.800 (0.016) | 0.800 (0.016) | 0.800 (0.030) | | 0.650 (0.007) | 0.650 (0.007) | 0.650 (0.007) | 0.650 (0.010) | | 0.350 (0.007) | 0.350 (0.007) | 0.350 (0.007) | 0.350 (0.010) | | 0.250 (0.006) | 0.250 (0.006) | 0.250 (0.006) | 0.250 (0.009) | | 0.750 (0.006) | 0.750 (0.006) | 0.750 (0.006) | 0.750 (0.009) | Convergence proportion (%) | 100 | 100 | 99.7 | 77.3 | Iterations | 31.2 (4.3) | 8.2 (1) | 5.7 (1.4) | 16 (0.5) | CPU time (secs) | 0.006 | 0.003 | 0.003 | 0.165 | Time ratio | 1.00 | 0.45 | 0.50 | 26.25 | Log-likelihood | -12832.34 | -12832.34 | -12832.39 | -12838.15 | MSE | | | | |
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