Implementing the Freight Transportation Data Architecture: Data Element Dictionary (2015) / Chapter Skim
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34 C H A P T E R 5 5.1 Introduction Freight data sources tend to be heterogeneous in terms of structure, syntax, and semantics (Buccella et al.
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Classifying Data Elements Across Databases 35 resolution across multiple freight data sources were not found. The classification schemes found in the review of the literature are described in this section.
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36 Implementing the Freight Transportation Data Architecture: Data Element Dictionary addresses four key business areas in transportation: (1) survey/roadway design, (2)
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Classifying Data Elements Across Databases 37 two types of elements is that only one "origin ID" can refer to a particular place in a database, but multiple places can each have "population" numbers, which are not necessarily unique. RBCS first determines and assigns a role to each data element within its database based on the primary and secondary level classification of that data element.
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38 Implementing the Freight Transportation Data Architecture: Data Element Dictionary From the nine primary and two secondary classification groups, the following classifications groups (or roles) were developed: • Time elements, which provide information regarding either the exact time period (e.g., year, month, time, day)
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Table 5-1. How RBCS groups data elements across databases.
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Mode Feature - Number of Carloads Car Ownership Category Code AAR Equipment Type Code AAR Mechanical Designation STB Car Type TOFC/COFC Service Code … CarrierGroup CarrierGroupNew DistanceGroup Class - - Commodity Identifier Commodity (STCG) Commodity Code (STCC)
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Classifying Data Elements Across Databases 41 classification roles was counted, and the ratio (classification efficiency) of classified elements to the total number of elements in a data source was calculated, as follows: Classification efficiency Classified Elements Classified Elements Unclassified elements = + Table 5-2 shows the classification efficiency of all 28 data sources.
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From page 42... ...
42 Implementing the Freight Transportation Data Architecture: Data Element Dictionary National Corridors Analysis and Speed Tool (N-CAST) database had 17 classified elements out of a total of 21 elements, which resulted in a classification efficiency of 81%.
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