POSC Specifications: Epicentre Version 3.0 | Logical Data Model |
Defines a relationship between two or three objects. The operation (e.g., intersection, addition, subtraction) of a primary object on an intersecting object produces a resulting object. For example, an edge is an object resulting from the intersection between two faces.
- ref_space_time_operation (M, K: ref_space_time_operation(space_time_operation)) (C138)
- This describes the kind of operation. Allowable operations include: intersection, proximity, projection, degeneration, addition and subtraction. Each space_time_operation must be a kind of one ref_space_time_operation.
- resulting_object (M, K: topological_object(source_space_time_operation))
- Indicates the topological object which resulted from a space/time operation. For intersection, this points to the object which represents the intersection of the two objects. For degeneration, this points to the object which is a degenerated form of the primary object. For projection, this points to the object which represents the projection of the primary object onto the intersecting object. For subtraction, this points to the object which is the result of subtracting from the primary object, the intersection between the primary and the intersecting object. For addition, this represents the union of the primary and intersecting objects. For proximity, this points to the object which is a subset of the primary object which is near the intersecting object. Each space_time_operation must result in one topological_object.
- primary_object (M: topological_object(primary_role))
- Indicates the topological object involved in a space/time operation in the role of primary agent (i.e., the thing we start with). For degeneration, this points to the object which is being degenerated. For projection, this points to the object which is being projected onto another object (the screen). For intersection and addition, this points to one of the objects participating in the relationship (i.e., both relationships must be searched to find a particular object). For proximity, this points to the container object which is near the intersecting object and of which the resulting object is a subset. For subtraction, this points to the object from which we are subtracting the intersection of the intersecting object. Each space_time_operation must use primarily one topological_object.
- description (O, I: ndt_comment) (C117)
- A remark or comment about the instance. Inherited from e_and_p_data.
- instance_create_date (O, I: ndt_date_tod) (C126)
- This is the date that this instance was created. This date is defined by the source if imported, or is the date the instance is created if a new instance. Inherited from e_and_p_data.
- instance_creator (O, I: ndt_identifier) (C126)
- This is the person, company or application that created this instance. This identifies the party responsible for loading this instance. Inherited from e_and_p_data.
- last_updated (O, I: ndt_date_tod) (C126)
- This is the date that this instance was last updated. This value should be updated when any part of this instance is altered (except for inverse relationships). Inherited from e_and_p_data.
- last_updated_by (O, I: ndt_identifier) (C126)
- This records the person or application making the update to this instance. Inherited from e_and_p_data.
- projection_vector (O: ndt_spherical_coordinates_complex_angle)
- The angle of projection. Depending upon the dimension of the space, the angle will be defined by one, two or three components.
- source (O, I: ndt_identifier) (C126)
- The provider of this instance, which is usually a data provider for imported/purchased data. If this instance is provided by POSC, then this attribute must be "POSC". Inherited from e_and_p_data.
- data_collection (I, V: SET[0:?] data_collection_content(collection_part)) (C020)
- Indicates the data collections that include this instance of E and P data. Each space_time_operation may be a member of one or more data_collection_content. Inherited from e_and_p_data.
- document_information_content (I, V: SET[0:?] document_information_content(e_and_p_data)) (C136)
- These are the document specification parts that include this data value and define its meaning within a document specification. Each use may define a different meaning, and many uses are allowed. Each space_time_operation may be included in one or more document_information_content. Inherited from e_and_p_data.
- graphical_element (I, V: SET[0:?] graphical_element(depicted_object))
- Specifies one or more graphical elements which are depicting this data item. Each space_time_operation may be depicted by one or more graphical_element. Inherited from e_and_p_data.
- intersecting_object (O: topological_object(intersection_role))
- Indicates the topological object involved in a space/time operation in the role of intersecting agent. For projection, this points to the screen on which the primary object is being projected. For intersection and addition, this points to one of the objects participating in the relationship (i.e., both relationships must be searched to find a particular object). For subtraction, this points to the object which is subtracted from the primary object. For proximity, this points to the magnet object that the primary object is near. Each space_time_operation may be made on one topological_object.
Local rules:
- Uniqueness Constraint
- ref_space_time_operation, resulting_object
Supertype path(s):
Referenced in Diagrams:
Generated on Tue Jul 10 15:54:27 2001
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