Showing papers by "Gregorio Díaz published in 2011"
TL;DR: An approach for the validation and verification of Web services choreographies, and more specifically, for those composite Web services systems with timing restrictions, by using the generated timed automata of WS-CDL (Web Services Choreography Description Language).
49 citations
05 Dec 2011
TL;DR: A set of satisfaction rules based on timed automata is defined to see whether a composition is compliant with the contract specification, providing the model with the mathematical rigour necessary for formal verification.
Abstract: In the field of service-oriented computing, an e-contract is used to regulate the acceptable behaviours of the services taking part in a composition. C-O Diagrams are a visual model for the specification of deontic e-contracts, including reparations, conditional clauses and real-time restrictions. In this work we define a set of satisfaction rules based on timed automata to see whether a composition is compliant with the contract specification, providing the model with the mathematical rigour necessary for formal verification.
7 citations
01 Sep 2011
TL;DR: An operational semantics for a language that integrates a well-known business process language (BPEL) with a recent technology for describing distributed resources throughout the Internet (WSRF) is defined.
Abstract: Web service compositions are gaining increasingly attention for the development of complex web systems by combination of existing ones. In this paper, we present a formal framework that integrates a well-known business process language (BPEL) with a recent technology for describing distributed resources throughout the Internet (WSRF). We define an operational semantics for a language that integrates both approaches taking into account the main features of them, such as notifications, event handling, fault handling and timed constraints.
6 citations
TL;DR: This paper presents a formal semantics for C-O Diagrams based on timed automata extended with an ordering of states and edges in order to represent different deontic modalities.
Abstract: C-O Diagrams have been introduced as a means to have a more visual representation of electronic contracts, where it is possible to represent the obligations, permissions and prohibitions of the different signatories, as well as what are the penalties in case of not fulfillment of their obligations and prohibitions. In such diagrams we are also able to represent absolute and relative timing constraints. In this paper we present a formal semantics for C-O Diagrams based on timed automata extended with an ordering of states and edges in order to represent different deontic modalities.
4 citations
04 Jul 2011
TL;DR: Two automatic methods are implemented that derive conforming systems even in cases where projecting the choreography into each service would lead to a non-conforming system.
Abstract: We present a tool to automatically derive choreography-conforming web services systems. The user provides a specification that describes peer-to-peer collaborations of the observable behavior of parties from a global viewpoint, in our case WS-CDL documents, and the tool automatically extracts the particular behavior of each participant, more concretely, WS-BPEL documents defining the behavior from a local viewpoint. We implement two automatic methods(centralized and decentralized) that derive conforming systems even in cases where projecting the choreography into each service would lead to a non-conforming system. This issue is addressed by adding some control messages that make services interact as required by the choreography. Experiments where the number of exchanged messages is measured are presented, and strategies to reduce the number of these messages are discussed.
3 citations
12 Sep 2011
TL;DR: In this paper, a formal semantics for C-O diagrams based on timed automata extended with an ordering of states and edges in order to represent different deontic modalities is presented.
Abstract: C-O Diagrams have been introduced as a means to have a more visual representation of electroniccontracts, where it is possible to represent the obligations, permissions and prohibitions of the dif-ferent signatories, as well as what are the penalties in case of not fulfillment of their obligations andprohibitions. In such diagrams we are also able to represent absolute and relative timing constraints.In this paper we present a formal semantics for C-O Diagrams based on timed automata extendedwith an ordering of states and edges in order to represent different deontic modalities.
2 citations
Proceedings Article•
20 Mar 2011TL;DR: This paper uses Web Services Resource Framework as a standard intended to the modelling of distributed resources using Web services, and applies formal techniques to WSRF specifications in order to analyse and verify these specifications.
Abstract: Throughout the history of computing, engineers have used various formal methods to improve the quality of software and hardware. The next natural step is trying to exploit their advantages in the so-called new era of computing: Cloud Computing. In this paper, we present a first approximation about how to simulate and check the behaviour of these systems using timed automata through the model checking tool UPPAAL. We use Web Services Resource Framework (WSRF) as a standard intended to the modelling of distributed resources using Web services, and we apply formal techniques to WSRF specifications in order to analyse and verify these specifications. Keywords-Web Services Resource Framework (WSRF); model checking; timed automata.