For operations, you can define an interface from which you implement operations. For these implemented operations, EmbeddedEngineer won't alter the operations name at all, because the interface defines a contract which includes the operations name. In EnterpriseArchitect, you can only implement operations though, and therefore an activity can't be implemented easily.
There is a workaround though: Operations in EnterpriseArchitect can be bound to behaviors, which includes activities. Therefore you need to do the following:
- Define an interface or use an already existing interface with a operation of the expected signature.
- Implement this interface in your class, typically adding an operation in the process.
- Make sure your activity has the same parameters (matching names and types) and the same return type (exactly equal type, it's recommended to use the same model element as type!) as the operation defined in the interface and implemented in the class containing the activity.
- In the properties of the operation, go to Behavior and select your activity.
- The generated code for the operation will call the activity, pass the parameters it received, and return the value from the activity.