67 research outputs found
Aspects of Assembly and Cascaded Aspects of Assembly: Logical and Temporal Properties
Highly dynamic computing environments, like ubiquitous and pervasive
computing environments, require frequent adaptation of applications. This has
to be done in a timely fashion, and the adaptation process must be as fast as
possible and mastered. Moreover the adaptation process has to ensure a
consistent result when finished whereas adaptations to be implemented cannot be
anticipated at design time. In this paper we present our mechanism for
self-adaptation based on the aspect oriented programming paradigm called Aspect
of Assembly (AAs). Using AAs: (1) the adaptations process is fast and its
duration is mastered; (2) adaptations' entities are independent of each other
thanks to the weaver logical merging mechanism; and (3) the high variability of
the software infrastructure can be managed using a mono or multi-cycle weaving
approach.Comment: 14 pages, published in International Journal of Computer Science,
Volume 8, issue 4, Jul 2011, ISSN 1694-081
Reflective Designs â An Overview
AbstractWe render runtime system adaptations by design-level concepts such that running systems can be adapted and examined at a higher level of abstraction. The overall idea is to express design decisions as applications of design operators to be carried out at runtime. Design operators can implement design patterns for use at runtime. Applications of design operators are made explicit as design elements in the running system such that they can be traced, reconfigured, and made undone.Our approach enables Reflective Designs: on one side, design operators employ reflection to perform runtime adaptations; on the other side, design elements provide an additional reflection protocol to examine and configure performed adaptations. Our approach helps understanding the development and the maintenance of the class of software systems that cannot tolerate downtime or frequent shutdown-revise-startup cycles.We have accumulated a class library for programming with Reflective Designs in Squeak/Smalltalk. This library employs reflection and dynamic aspect-oriented programming. We have also implemented tool support for navigating in a system that is adapted continuously at runtime.Note: This extended abstract summarises our full paper [Hirschfeld, R. and R. LĂ€mmel, Reflective Designs, IEE Proceedings Software (2004), Special Issue on Reusable Software Libraries. To appear. Available at http://homepages.cwi.nl/~ralf/rd/]
Two ways to Grid: the contribution of Open Grid Services Architecture (OGSA) mechanisms to service-centric and resource-centric lifecycles
Service Oriented Architectures (SOAs) support service lifecycle tasks, including Development, Deployment, Discovery and Use. We observe that there are two disparate ways to use Grid SOAs such as the Open Grid Services Architecture (OGSA) as exemplified in the Globus Toolkit (GT3/4). One is a traditional enterprise SOA use where end-user services are developed, deployed and resourced behind firewalls, for use by external consumers: a service-centric (or âfirst-orderâ) approach. The other supports end-user development, deployment, and resourcing of applications across organizations via the use of execution and resource management services: A Resource-centric (or âsecond-orderâ) approach. We analyze and compare the two approaches using a combination of empirical experiments and an architectural evaluation methodology (scenario, mechanism, and quality attributes) to reveal common and distinct strengths and weaknesses. The impact of potential improvements (which are likely to be manifested by GT4) is estimated, and opportunities for alternative architectures and technologies explored. We conclude by investigating if the two approaches can be converged or combined, and if they are compatible on shared resources
Combining Ontology Alignment with Model Driven Engineering Techniques for Home Devices Interoperability
International audienceUbiquitous Systems are expected in the near future to have much more impact on our daily tasks thanks to advances in embedded systems, "Plug-n-Play" protocols and software architectures. Such protocols target home devices and enables automatic discovery and interaction among them. Consequently, smart applications are shaping the home into a smart one by orchestrating devices in an elegant manner. Currently, several protocols coexist in smart homes but interactions between devices cannot be put into action unless devices are supporting the same protocol. Furthermore, smart applications must know in advance names of services and devices to interact with them. However, such names are semantically equivalent but syntactically different needing translation mechanisms. In order to reduce human efforts for achieving interoperability, we introduce an approach combining ontology alignment techniques with those of Model Driven Engineering domain to reach a dynamic service adaptation
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Multimedia delivery in the future internet
The term âNetworked Mediaâ implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizensâ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications âon the moveâ, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
A Conceptual Framework for Adapation
This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions
A Conceptual Framework for Adapation
We present a white-box conceptual framework for adaptation. We called it CODA, for COntrol Data Adaptation, since it is based on the notion of control data. CODA promotes a neat separation between application and adaptation logic through a clear identification of the set of data that is relevant for the latter. The framework provides an original perspective from which we survey a representative set of approaches to adaptation ranging from programming languages and paradigms, to computational models and architectural solutions
Evaluating performance of web services in cloud computing environment with high availability
This paper presents an methodology for attaining high availability to the demands of the web clients. In order to improve in response time of web services during peak hours dynamic allocation of host nodes will be used in this research work. As web users are very demanding: they expect web services to be quickly accessible from the world 24*7. Fast response time leads to high availability of web services, while slow response time degrades the performance of web services. With the increasing trend of internet, it becomes a part of life. People use internet to help in their studies, business, shopping and many more things. To achieve this objective LAMP platform is used which are Linux, Apache, My SQL, and PHP. LAMP is used to increase the quality of product by using open source software. The proposed strategy will work as middle layer and provide highly availability to the web clients
A Conceptual Framework for Adapation
This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions
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