123,993 research outputs found

    Juno:An adaptive delivery-centric middleware

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    This paper proposes a new delivery-centric abstraction. A delivery-centric abstraction allows applications to generate content requests agnostic to location or protocol, with the additional ability to stipulate high-level requirements regarding such things as performance, security, resource consumption and monetary cost. A delivery-centric system therefore constantly adapts to fulfil these requirements, given the constraints of the environment. This abstraction has been realised through a delivery-centric middleware called Juno, which uses a reconfigurable software architecture to (i) discover multiple sources of an item of content, (ii) model each source's ability to provide the content, then (iii) adapt to interact with the source(s) that can best fulfil the application's requirements. Juno therefore utilises existing providers in a backwards compatible way, supporting immediate deployment. This paper evaluates Juno using Emulab to validate its ability to adapt to its environment

    Resolving Architectural Mismatches of COTS Through Architectural Reconciliation

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    The integration of COTS components into a system under development entails architectural mismatches. These have been tackled, so far, at the component level, through component adaptation techniques, but they also must be tackled at an architectural level of abstraction. In this paper we propose an approach for resolving architectural mismatches, with the aid of architectural reconciliation. The approach consists of designing and subsequently reconciling two architectural models, one that is forward-engineered from the requirements and another that is reverse-engineered from the COTS-based implementation. The final reconciled model is optimally adapted both to the requirements and to the actual COTS-based implementation. The contribution of this paper lies in the application of architectural reconciliation in the context of COTS-based software development. Architectural modeling is based upon the UML 2.0 standard, while the reconciliation is performed by transforming the two models, with the help of architectural design decisions.

    Evolving information systems: meeting the ever-changing environment

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    To meet the demands of organizations and their ever-changing environment, information systems are required which are able to evolve to the same extent as organizations do. Such a system has to support changes in all time-and application-dependent aspects. In this paper, requirements and a conceptual framework for evolving information systems are presented. This framework includes an architecture for such systems and a revision of the traditional notion of update. Based on this evolutionary notion of update (recording, correction and forgetting) a state transition-oriented model on three levels of abstraction (event level, recording level, correction level) is introduced. Examples are provided to illustrate the conceptual framework for evolving information systems

    A tutorial on simulation conceptual modeling

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    © 2017 IEEE. Conceptual modeling is the abstraction of a simulation model from the part of the real world it is representing; in other words, choosing what to model, and what not to model. This is generally agreed to be the most difficult, least understood, but probably the most important activity to be carried out in a simulation study. In this tutorial we explore the definition, requirements and approach to conceptual modeling. First we ask 'where is the model?' We go on to define the term 'conceptual model', to identify the artefacts of conceptual modeling, and to discuss the purpose and benefits of a conceptual model. In so doing we identify the role of conceptual modeling in the simulation project life-cycle. The discussion then focuses on the requirements of a conceptual model, the approaches for documenting a conceptual model, and frameworks for guiding the conceptual modeling activity. One specific framework is described and illustrated in more detail. The tutorial concludes with a discussion on the level of abstraction

    A methodology for CIM modelling and its transformation to PIM

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    Developing with Model Driven Architecture is nowadays widely used starting with a CIM that can be transformed to models of low abstraction (PIM, PSM) that can be used to generate the code. The CIM represents the highest level of abstraction of the approach which allowing modeling system’s requirement. However, there is no standard method to build this type of model or how to transform it to lower level of abstraction (PIM) which is considered the final objective of building such model. This paper provides an approach to build the CIM that can be transformed (semi-) automatically later to lower levels of abstraction in PIMs.  Thereby, the proposed architecture represents both the static and dynamic view of the system based on the business process model. Meanwhile, the PIM level is represented by the Domain Diagram class and Sequence Diagram of Systems External behavior. Thus, the proposal helps bridging the gap between those that are experts about the domain and its requirements, and those that are experts of the system design and development. Keywords: CIM to PIM transformation; MDA; software process
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