Clarification on Cardinality and Participation
After further research, and for anyone else in the future, I thought I would post what I have learned looking into this topic. Credit mostly goes to "Data Modeling and Database Design" by Narayan S. Umanath and Richard W. Scamell (2nd Edition).

I came up with following participation and cardinality:


In reference to the relationship above, I determined the participation and cardinality for the entity "Objects" in the "has" relationships to be optional (0) with a cardinality of many (m). The reason is because the foreign key "schedule_ID" in the "Objects" table is an optional attribute, meaning "Objects" does not have mandatory participation in the relationship. Additionally, the business logic dictates that each tuple in the "Objects" table can only correspond to one tuple in the "schedule" table.

For the (0,m) that defines the participation and cardinality of the "schedule" entity in the relationship "has", parent entities in relationships are rarely total participation, meaning in majority of cases (unless specific business logic requires it) they have partial partition (denoted by the "0"). For the cardinality, each tuple in the "schedule" table can be related to many objects.

Additionally, I compiled the following notes while looking into this that might be helpful in these types of cases (creating ERD for existing databases):
- by default, relationships between parents and children are (0,m)(0,1).
- can not enforce mandatory participation on parent side without the use of triggers.
- in order to for participation on child entity, put a NOT NULL constraint on the foreign key fields.
- to specify alternative keys (candidate keys), you can place a UNIQUE constraint.

I invite others to offer comments and critique. Hope this helps someone!