Project "Orleans" invented the Virtual Actor abstraction, which provides a straightforward approach to building distributed interactive applications, without the need to learn complex programming patterns for handling concurrency, fault tolerance, and resource management. Orleans applications scale-up automatically and are meant to be deployed in the cloud. The i * framework proposes an agent-oriented approach to requirements engineering centering on the intentional characteristics of the agent. Agents attribute intentional properties (such as goals, beliefs, abilities, commitments) to each other and reason about strategic relationships. Actors. In Gazebo, an animated model is called an actor. Actors extend common models, adding animation capabilities. There are two types of animations which can be used separately or combined together: Skeleton animation, which is relative motion between links in one model: • The Actor model of concurrency was developed alongside a functional programming language called Erlang • Erlang is 20-years old (!) and has been used heavily in the telecom industry • In Erlang, Actors are implemented by a framework called OTP • OTP has the ability to create thousands of actors, distribute them Use Case Descriptions • actors - something with a behavior or role, e.g., a person, another system, organization. • scenario - a specific sequence of actions and interactions between actors and the system, a.k.a. a use case instance • use case - a collection of related success and failure scenarios, describing actors using the system to Problems of the Actor Model The actor model has no direct notion of inheritance or hierarchy, which means it is time consuming and confusing to program actors with trends of common behaviour. Actors allow abstraction of the concepts, but in almost all non-trivial programs there will be many kinds of abstraction. Modding Tutorials. Want to contribute to UT? Give your own spin on things? It's easier than you t