1 Introduction
2 Related work
3 The dynamic railway junction rescheduling problem
3.1 Description of the problem
3.2 The extended DRJRP
Time passed (min) | Platform 1 | Platform 2 |
---|---|---|
10 | Train 14 | Train 16 |
Train 18 | ||
20 | Train 26 | Train 28 |
30 | Train 30 | |
40 | Train 38 | Train 40 |
Train 42 | ||
50 | Train 50 | Train 52 |
60 | Train 54 |
Train number | Train type | Route | Delay penalty (£/min) | Scheduled arrival | Station platform |
---|---|---|---|---|---|
1 | Class 150 | A–D | 20 | 12:10 | 1 |
2 | Class 220 | D–A | 40 | 12:12 | 1 |
3 | Freight | B–C | 10 | 12:19 | 1 |
4 | Class 220 | D–B | 40 | 12:15 | 2 |
5 | Freight | B–D | 10 | 12:20 | 2 |
6 | Class 150 | D–B | 20 | 12:19 | 1 |
7 | Freight | A–C | 10 | 12:28 | 2 |
8 | Class 150 | C–A | 20 | 12:22 | 1 |
9 | Class 220 | C–A | 40 | 12:27 | 2 |
10 | Class 220 | B–C | 40 | 12:32 | 3 |
11 | Freight | C–B | 10 | 12:39 | 1 |
12 | Class 150 | A–D | 20 | 12:36 | 3 |
3.3 The Stenson Junction train simulator
3.4 The extended Stenson Junction train simulator
4 ACO for dynamic optimization problems (DOPs)
4.1 Basic ACO algorithm
4.2 Max–Min ant system (MMAS)
4.3 Population-based ACO (P-ACO)
4.4 ACO for dynamic rescheduling
4.5 Using immigrants for DOPs
5 Proposed P-ACO algorithm for the extended DRJRP
5.1 Framework of the proposed algorithms
5.2 Adapting the memory in P-ACO after a change
5.3 Random immigrants
5.4 Elite immigrants
5.5 Path-preserving local search
5.5.1 Forward pass
5.5.2 Backward pass
5.6 Hybrid immigrants
Abbreviation | Algorithm description | Station sequencing |
---|---|---|
EI-PACO | P-ACO where the memory is replaced with repaired elite immigrants after a change | Yes |
RI-PACO | P-ACO where the memory is replaced with repaired random immigrants after a change | Yes |
HI-PACO | P-ACO where the memory is replaced with repaired elite and random immigrants after a change | Yes |
NSS-PACO | P-ACO where the ants in memory are retained and repaired with KeepElitist repair operation | No |
MMAS | The Max–Min AS algorithm | Yes |
5.7 Dynamics implementation
5.8 Handling constraints
6 Experimental study
6.1 Experimental setting
6.2 Experiment results
Algorithms | 1 station delay | 2 station delays | ||||
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\(f \Rightarrow \) 5 | 10 | 15 |
\(f \Rightarrow \) 5 | 10 | 15 | |
RI-PACO \(\Leftrightarrow \) FCFS |
s
\(-\)
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s
\(+\)
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\(+\)
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s
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EI-PACO \(\Leftrightarrow \) FCFS |
s
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s
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s
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s
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s
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HI-PACO \(\Leftrightarrow \) FCFS |
s
\(+\)
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s
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\(+\)
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s
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s
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NSS-PACO \(\Leftrightarrow \) FCFS |
s
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s
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\(+\)
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s
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s
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\(+\)
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MMAS \(\Leftrightarrow \) FCFS |
\(-\)
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s
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\(+\)
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\(-\)
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s
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\(+\)
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RI-PACO \(\Leftrightarrow \) EI-PACO |
s
\(-\)
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s
\(-\)
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\(-\)
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s
\(-\)
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s
\(-\)
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\(-\)
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RI-PACO \(\Leftrightarrow \) HI-PACO |
s
\(-\)
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s
\(-\)
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\(-\)
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s
\(-\)
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s
\(-\)
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\(-\)
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RI-PACO \(\Leftrightarrow \) NSS-PACO |
s
\(-\)
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s
\(-\)
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\(-\)
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s
\(-\)
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s
\(-\)
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\(-\)
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RI-PACO \(\Leftrightarrow \) MMAS |
s
\(-\)
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\(-\)
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\(-\)
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s
\(-\)
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\(-\)
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\(-\)
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EI-PACO \(\Leftrightarrow \) HI-PACO |
\(+\)
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\(+\)
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\(+\)
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\(+\)
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\(-\)
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EI-PACO \(\Leftrightarrow \) NSS-PACO |
\(-\)
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\(-\)
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\(+\)
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s
\(-\)
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\(-\)
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EI-PACO \(\Leftrightarrow \) MMAS |
s
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s
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s
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s
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HI-PACO \(\Leftrightarrow \) NSS-PACO |
\(-\)
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\(-\)
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\(+\)
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s
\(-\)
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s
\(-\)
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\(+\)
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HI-PACO \(\Leftrightarrow \) MMAS |
s
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s
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\(+\)
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s
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s
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NSS-PACO \(\Leftrightarrow \) MMAS |
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s
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\(+\)
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s
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s
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\(-\)
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6.3 Algorithm computation time
Change | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Average | 1.43 | 1.47 | 1.84 | 2.10 |
Minimum | 1.36 | 1.37 | 1.63 | 1.85 |
Maximum | 1.49 | 1.66 | 2.08 | 2.52 |
Evaluation (%) | 99.90 | 99.90 | 99.92 | 99.92 |
Change | 1 | 2 | 3 | 4 | 12 |
---|---|---|---|---|---|
Average | 1.97 | 2.89 | 3.96 | 5.07 | 18.87 |
Minimum | 1.93 | 2.77 | 3.77 | 4.81 | 17.16 |
Maximum | 2.02 | 3.03 | 4.25 | 5.47 | 34.82 |
Evaluation (%) | 99.91 | 99.92 | 99.93 | 99.93 | 99.95 |