## 2 Ontology of Transportation Systems  
In this section, the most important ontology systems are presented that have been developed over the past years. Figure 1 presents an overview of the ontology systems used in the field of logistics. An _ontology for constructing scheduling systems_ developed by _[PERSON]_[41] in 1994 was one of the first works used. The building blocks of the ontology system included the following five classes: 'Demand', 'Activity', 'Resource', 'Product', and 'Constraint', 'Demand' was the demand for products and services. The 'Product' was associated with 'Demand' and included the following properties: 'Activities', and 'Resources'. 'Resources' supported the implementation of 'Activities'. The following properties were defined for 'Resources': 'Capacity', 'Setup-Duration', and 'Usage-Restrictions'. Properties were also defined for the 'Activities' class: 'Start-Time', 'End-Time', 'Duration' etc. A _multi-agent logistics scheduler for road transportation_ system was reported by _[PERSON], [PERSON], and [PERSON]_ in _2006_[42]. In this paper, a model of intelligent road transport scheduling was presented, which included several functions such as real-time scheduling, scheduling improvement, and scheduling analysis. The scheduler was event-driven, which means that schedules were compiled to consider all events that affect the schedule (e.g., the arrival of a new order, cancellation of an order, truck failure, or lack of travel). When an event occurred, the scheduler rescheduled only the affected part, thereby minimizing the change to resources that had already been allocated. Their system consisted of three main components: 'Basic', 'Operations', and 'Scheduling'. In an article by _[PERSON], [PERSON], and [PERSON]_[43] published in 2007, an _ontology for semantic representation of the situation in logistics_ was performed. The following 'Logistics Processes'  
Figure 1: Overview of ontology systems used in logistics. were covered: 'Outsourcing', 'Manufacture', 'Warehouse', 'Inventory', 'Maintenance', 'Order', 'Packing', 'Load', 'Transportation', 'Unload', 'Distribution', 'Reverse Logistics'. The following 'Logistics Events' elements were defined: 'Material_Arrived', 'Products Exist', 'Warehoused', 'Inventoried', 'Temperature_Regulated', 'Maintaining', 'Stock Check', 'Packed', 'Back Order', 'Loaded', 'Transport', 'Products_Arrived', 'Unload', 'Distributing', 'Back Out'. _[PERSON], [PERSON], and [PERSON]_ discussed a _transport service ontology_ in 2008 [44]. The authors divided the ontology system into layers. The first layer was the root of the hierarchy, which includes all delivery services. The second layer was a specialization of the concept of abstract transport service, comprising four categories: air transport, rail transport, road transport, and shipping services. The third layer was a further specialization of the second layer, in this service the service concepts can be considered concrete or abstract concepts. In the third layer, the abstract concepts had additional specializations in the fourth layer. In their 2010 publication [45], the authors _[PERSON], [PERSON], and [PERSON]_ reported an _ontology model for flexibility in supply chain configuration and management_. The approach combined loosely coupled logistics services and semantic technologies to provide a unified representation of different logistics data and service functions. The authors created a framework that used automated, intelligent techniques to discover, rank, and execute efficient assemblies of services. The following main concepts were discussed in connection with the system: 'Process', 'Service', and 'Resource'. 'Process Logistics Process' could be 'Service Logistics Service'. 'Logistics Service' further specialized in 'Service Provider', 'Service Requester', 'Transportation', 'Handling, and 'Storage'. An _ontology model for exception monitoring service_ was presented by _[PERSON], [PERSON], [PERSON], and [PERSON]_ in 2012 [46]. The system modeled logistics exceptions.