Recitation II

  • ​Ontology Construction
  • UML Diagramming

Ontology Construction

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UML Diagramming

  1. A network consists of nodes connected through a hub. A router, which is also a node, connects networks. A bridge is used to connect dissimilar networks. Each device on a network operates according to a network protocol and several speeds.
  2. A course is divided into unit. Each unit has up to five lessons. Each lessons has readings and video tutorials. Video tutorials, readings, lessons, units, and courses take a certain amount of time to complete.
  3. A recipe requires ingredients and steps in which the ingredients are used. Ingredients are measured and require certain quantities.
  4. A grocery delivery order contains items from up to three stores. Each item comes from only one stores and is bought at a certain quantity and price. Many, but not all, items have substitutions.

Worked Example

Once you have the diagram in LucidChart connect the classes in red with the proper relationships and where appropriate multiplicity constraints on the relationships. The additional classes (terms, entities) represent the following insights:
  1. a message can be sent to a group of contacts or a single contact; both are considered to be the message's recipient
  2. a contact can be in more than one group; some contacts are not in any group; groups have names
  3. a message has a flag, isRead, that is TRUE if the message has been read, FALSE otherwise and by default
  4. all contacts are organized in a contact list; a user may have more than one contact list and a contacts may be in one or more contact lists but must be in at least one contact list
  5. photos can also be types of content; each photo has a resolution and a format (JPG, PNG, TIFF); videos also have a resolution and a format (MP4, WMV, etc.); audio has a sampling rate (8kHz, 16kHz, etc) and a length (in seconds); content has a text string that's the message, an encoding format (e.g., UNICODE) and a language (e.g., English, French)
  6. while a message can only have a single content, it can have up to 32 attachments (add the multiplicity where the ??? is)
  7. an attachment is not the same as content; content contains text and/or emojis or a GIF (which can be animated); you cannot have text plus an animated GIF
  8. a message is always sent to a single recipient, although that recipient can receive many messages, possibly none
  9. when a message is sent to a group, then any attachments are shared among the message to conserve space
  10. there's an archive of messages that collects all messages that have been deleted
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