Humberto Nicolás Castejón

Learn More
This paper is concerned with compositional specification of services using UML 2 collaborations, activity and interaction diagrams. It addresses the problem of realizability: given a global specification, can we construct a set of communicating state machines whose joint behavior is precisely the specified one? We approach the problem by looking at how(More)
Collaborations and collaboration uses are features new to UML 2.0. They possess many properties that support rapid and compositional service engineering. The notion of collaboration corresponds well with the notion of a service, and it seems promising to use them for service specification. We present an approach where collaborations are used to specify(More)
Telecommunication services are provided as the joint effort of components, which collaborate in order to achieve the goal(s) of the service. UML 2.0 collaborations can be used to model services. Furthermore , they allow services to be described modularly and incrementally, since collaborations can be composed of subordinate collaborations. For such an(More)
Methods for service specification should be simple and intuitive. At the same time they should be precise and allow early validations to be performed, in order to detect inconsistencies as early as possible in the service development cycle. In this paper we present a service specification approach based on UML 2.0 collaborations. It aims to be a(More)
The uptake of Cloud computing is being hindered by the fact that not only are current Cloud SLAs written in natural language, but they also fail to cover security requirements. This paper considers a Cloud brokering model that helps negotiate and establish SLAs between customers and providers. This broker handles security requirements on two different(More)
This paper considers compositional specifications of services using UML 2 collaborations, activity and interaction diagrams, and addresses the realizability problem for such specifications: given a global specification, can we construct a set of communicating system components whose joint behavior is precisely the specified global behavior? We approach the(More)
Many services are provided by a structure of service components that are dynamically bound and performed by system components. Service modularity requires that service components can be developed separately , deployed dynamically and then used to provide situated services without undesirable service interactions. In this paper we introduce a two-dimensional(More)
This report is concerned with compositional specification of services using UML 2 collaborations, activity and interaction diagrams. It provides formal syntax and semantics for so-called choreography graphs, used to describe the complete behavior of composite collaborations. It then addresses the problem of realizability: given a global specification, can(More)