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In a transportation system, OD pairs are usually accumulated by large quantities of primary records. The records may come from train tickets, freight invoices, and flight trip tickets etc. In 2013, 2.075 billion passengers are transported by China railway. Each train ticket contains information of origin and destination stations, train number, and train class etc. Only several fields of information, such as origin and destination, are required according to specific research purposes. The rest of the fields are unnecessary and need to be merged. A direct merging method in which each record compares with all existing OD pairs will consume a lot of time when there are large quantities of records. This work will propose a sorting-based merging method, which applies to general OD matrices. The time complexity is scale of O(NlogN) . For tests, 30 samples are used for numerical analyses. The results show that the efficiency is far better than that of the direct merging method. |
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Keywords:OD matrix, Railway ticket, merging, sorting |
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