57,432 research outputs found
Coordination Contracts as Connectors in Component-Based Development
Several proposals for component-based development
methods have started to appear. However, the emphasis is
still very much on the development of components as
opposed to the development with components. The main
focus is on how to generate ideal reusable components not
on how to plug existing components and specify their
interactions and connections.
The concept of a coordination contract (Andrade and
Fiadeiro 1999; Andrade and Fiadeiro 2001; Andrade,
Fiadeiro et al. 2001) has been proposed to specify a
mechanism of interaction between objects based on the
separation between structure, what is stable, and
interaction, what is changeable. This separation supports
better any change of requirements, as contracts can be
replaced, added or removed dynamically, i.e. in run-time,
without having to interfere with the components that they
coordinate. A coordination contract corresponds to an
expressive architectural connector that can be used to plug
existing components.
In this paper we integrate the concept of a coordination
contract with component-based development and show
how coordination contracts can be used to specify the
connectors between components
Generating a contract checker for an SLA language
SLAng is a language for expressing Service LevelAgreements (SLAs) under development as part of the Europeanproject TAPAS. It is defined using a meta-model, an instance ofthe Meta-Object Facility (MOF) model, in which the relationshipbetween the syntax of the language and its domain of applicationis explicitly represented, and the violation semantics ofthe language defined using Object Constraint Language (OCL)constraints. The concrete syntax of the language is the XMLMeta-data Interchange (XMI) mapping of the syntactic part ofthe meta-model. In this paper we describe how the Java MetadataInterface (JMI) mapping can be applied to the meta-modelof the language to generate interfaces and classes to create andquery SLAs and relevant service monitoring data in memory;and how an OCL interpreter can be applied to check violationconstraints over this data, resulting in the implementation of acontract checker that is highly likely to respect the semantics ofthe language
Tele-education Process Modelling supported by the ODP Enterprise Viewpoint Language
This paper reports on applying the ODP enterprise viewpoint in the domain of tele-education. The work is conducted as part of a research activity that aims at designing a tele-education system to support planning, execution and evaluation of dynamic distributed educational processes. We explore the ODP enterprise viewpoint as a basis for communication and co-operation between educational scientists and ODP systems designers involved in the design process. Our application of the enterprise viewpoint involves four main steps. First, an educational language is proposed to describe educational processes in generic terms. Second, a set of appropriate enterprise language concepts is selected. Third, a relationship is established between the educational language and enterprise language concepts. Fourth, an educational process is modelled in terms of an entity-oriented model and a behaviour-oriented model. It is hoped that the experience gained in this exercise will provide useful feedback to both the educational and ODP communitie
A Rigorous Approach to Relate Enterprise and Computational Viewpoints
Multiviewpoint approaches allow stakeholders to design a system from stakeholder-specific viewpoints. By this, a separation of concerns is achieved, which makes designs more manageable. However, to construct a consistent multiviewpoint design, the relations between viewpoints must be defined precisely, so that the consistency of designs from these viewpoints can be verified. The goal of this paper is to make the consistency rules between (a slightly adapted version of) the RM-ODP enterprise and computational viewpoints more precise and to make checking the consistency between these viewpoints practically applicable. To achieve this goal, we apply a generic framework for relating viewpoints that includes reusable consistency rules. We implemented the consistency rules in a tool to show their applicability
An Architecture for Provenance Systems
This document covers the logical and process architectures of provenance systems. The logical architecture identifies key roles and their interactions, whereas the process architecture discusses distribution and security. A fundamental aspect of our presentation is its technology-independent nature, which makes it reusable: the principles that are exposed in this document may be applied to different technologies
Specification of multiparty audio and video interaction based on the Reference Model of Open Distributed Processing
The Reference Model of Open Distributed Processing (RM-ODP) is an emerging ISO/ITU-T standard. It provides a framework of abstractions based on viewpoints, and it defines five viewpoint languages to model open distributed systems. This paper uses the viewpoint languages to specify multiparty audio/video exchange in distributed systems. To the designers of distributed systems, it shows how the concepts and rules of RM-ODP can be applied.\ud
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The ODP ¿binding object¿ is an important concept to model continuous data flows in distributed systems. We take this concept as a basis for multiparty audio and video flow exchanges, and we provide five ODP viewpoint specifications, each emphasising a particular concern. To ensure overall correctness, special attention is paid to the mapping between the ODP viewpoint specifications
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