# Modeling of Historical Marine Casualty on S-100 Electronic Navigational Charts
## 3 Method: Data Modeling of Marine Casualty
### Application Schema Definition  
Application schema definition is the process of formally defining data types, attributes, and relationships based on the information elements and requirements identified. This step provides the structural foundation that ensures data can be consistently generated, interpreted, and exchanged within application systems such as ECDIS. It also serves as the starting point for creating the FC and datasets. As required by the S-100 standard, the application schema is formally expressed using UML and is designed in accordance with the structure and rules defined in the GFM. The key requirements identified for modeling marine casualty data are ensuring consistent representation of attributes common to all types of incidents, capturing characteristics specific to each incident type, and enabling extensibility to accommodate emerging types of incidents. These requirements are reflected in the application schema defined in this study, which is presented as a UML diagram in Figure 3. To define a structure that includes common attributes, a feature type named _Casually_ was created and is structured by inheriting from the upper-level element (_S100_GF_FeatureType_) defined in the S-100 GFM as the basic structure for feature type definition. The requirement to distinguish incidents based on their spatial and functional characteristics was addressed by defining multiple concrete feature types that inherit from _Casually_. This approach eliminates the need to repeatedly define shared attributes for each incident type and enables the addition of specialized attributes for individual types. As a result, a hierarchical structure was established that accommodates both commonality and specificity. In anticipation of the increasing diversity of incident types due to developments such as smart ship technologies, the classification of incident types was defined using S100_CodeList. The code lists defined as classes on the right side of the diagram contain enumerated values representing incident subtypes and are designed to support extension without requiring structural changes to the model. When new incident types need to be added, the application schema must be updated accordingly, and the new code list values should be submitted to the IHO Registry. These submissions are reviewed by the appropriate domain control body and must be formally approved before the values can be officially registered and used within S-100-compliant systems [2]. Table 3 presents the structure of the marine casualty data model defined in this study, showing all feature types illustrated in Figure 3 along with their defined attributes and structural relationships. The _Casually_ feature type is defined to include only the attributes that are commonly applicable to all types of marine casualties. This feature contains only common properties and does not represent any specific incident type, so it is designated as an abstract feature type. This prevents unspecified incidents from being included in the dataset and ensures structural consistency by allowing concrete subtypes to inherit its attributes. Each concrete feature type inherits from _Casually_ and defines one additional attribute to represent a specific subclass of incidents. Table 4 presents the attributes of the abstract feature type _Casualty_, which includes common information shared across different types of marine incidents. This feature includes attributes such as the date and time of the incident, human casualties, a textual description of the incident, vessel identification information, and the location of the event. The _location_ attribute is defined as a complex attribute comprising latitude and longitude. In the S-100 standard, complex attributes are modeled as separate classes composed of simple attributes. The _geometry_ attribute has the data type GM_Point, which is a spatial object based on the ISO 19107, _Spatial schema_[33]. It represents a point feature that enables the incident location to be visually displayed on ENCs.