244,073 research outputs found
The Athena Data Dictionary and Description Language
Athena is the ATLAS off-line software framework, based upon the GAUDI
architecture from LHCb. As part of ATLAS' continuing efforts to enhance and
customise the architecture to meet our needs, we have developed a data object
description tool suite and service for Athena. The aim is to provide a set of
tools to describe, manage, integrate and use the Event Data Model at a design
level according to the concepts of the Athena framework (use of patterns,
relationships, ...). Moreover, to ensure stability and reusability this must be
fully independent from the implementation details. After an extensive
investigation into the many options, we have developed a language grammar based
upon a description language (IDL, ODL) to provide support for object
integration in Athena. We have then developed a compiler front end based upon
this language grammar, JavaCC, and a Java Reflection API-like interface. We
have then used these tools to develop several compiler back ends which meet
specific needs in ATLAS such as automatic generation of object converters, and
data object scripting interfaces. We present here details of our work and
experience to date on the Athena Definition Language and Athena Data
Dictionary.Comment: 4 pages, 2 figure
On the Notion of Abstract Platform in MDA Development
Although platform-independence is a central property in MDA models, the study of platform-independence has been largely overlooked in MDA. As a consequence, there is a lack of guidelines to select abstraction criteria and modelling concepts for platform-independent design. In addition, there is little methodological support to distinguish between platform-independent and platform-specific concerns, which could be detrimental to the beneficial exploitation of the PIM-PSM separation-of-concerns adopted by MDA. This work is an attempt towards clarifying the notion of platform-independent modelling in MDA development. We argue that each level of platform-independence must be accompanied by the identification of an abstract platform. An abstract platform is determined by the platform characteristics that are relevant for applications at a certain level of platform-independence, and must be established by balancing various design goals. We present some methodological principles for abstract platform design, which forms a basis for defining requirements for design languages intended to support platform-independent design. Since our methodological framework is based on the notion of abstract platform, we pay particular attention to the definition of abstract platforms and the language requirements to specify abstract platforms. We discuss how the concept of abstract platform relates to UML
Kompics: a message-passing component model for building distributed systems
The Kompics component model and programming framework was designedto simplify the development of increasingly complex distributed systems. Systems built with Kompics leverage multi-core machines out of the box and they can be dynamically reconfigured to support hot software upgrades. A simulation framework enables deterministic debugging and reproducible performance evaluation of unmodified Kompics distributed systems.
We describe the component model and show how to program and compose event-based distributed systems. We present the architectural patterns and abstractions that Kompics facilitates and we highlight a case study of a complex
distributed middleware that we have built with Kompics. We show how our approach enables systematic development and evaluation of large-scale and dynamic distributed systems
Semantics as a gateway to language
This paper presents an account of semantics as a system that integrates conceptual representations into language. I define the semantic system as an interface level of the conceptual system CS that translates conceptual representations into a format that is accessible by language. The analysis I put forward does not treat the make up of this level as idiosyncratic, but subsumes it under a unified notion of linguistic interfaces. This allows us to understand core aspects of the linguistic-conceptual interface as an instance of a general pattern underlying the correlation of linguistic and non-linguistic structures. By doing so, the model aims to provide a broader perspective onto the distinction between and interaction of conceptual and linguistic processes and the correlation of semantic and syntactic structures
Event notification services: analysis and transformation of profile definition languages
The integration of event information from diverse event notification sources is, as with meta-searching over heterogeneous search engines, a challenging task. Due to the complexity of profile definition languages, known solutions for heterogeneous searching cannot be applied for event notification.
In this technical report, we propose transformation rules for profile rewriting. We transform each profile defined at a meta-service into a profile expressed in the language of each event notification source. Due to unavoidable asymmetry in the semantics of different languages, some superfluous information may be delivered to the meta-service. These notifications are then post-processed to reduce the number of spurious messages. We present a survey and classification of profile definition languages for event notification, which serves as basis for the transformation rules. The proposed rules are implemented in a prototype transformation module for a Meta-Service for event notification
Enforcing reputation constraints on business process workflows
The problem of trust in determining the flow of execution of business processes has been in the centre of research interst in the last decade as business processes become a de facto model of Internet-based commerce, particularly with the increasing popularity in Cloud computing. One of the main mea-sures of trust is reputation, where the quality of services as provided to their clients can be used as the main factor in calculating service and service provider reputation values. The work presented here contributes to the solving of this problem by defining a model for the calculation of service reputa-tion levels in a BPEL-based business workflow. These levels of reputation are then used to control the execution of the workflow based on service-level agreement constraints provided by the users of the workflow. The main contribution of the paper is to first present a formal meaning for BPEL processes, which is constrained by reputation requirements from the users, and then we demonstrate that these requirements can be enforced using a reference architecture with a case scenario from the domain of distributed map processing. Finally, the paper discusses the possible threats that can be launched on such an architecture
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