45 research outputs found

    Towards Adaptable and Adaptive Policy-Free Middleware

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    We believe that to fully support adaptive distributed applications, middleware must itself be adaptable, adaptive and policy-free. In this paper we present a new language-independent adaptable and adaptive policy framework suitable for integration in a wide variety of middleware systems. This framework facilitates the construction of adaptive distributed applications. The framework addresses adaptability through its ability to represent a wide range of specific middleware policies. Adaptiveness is supported by a rich contextual model, through which an application programmer may control precisely how policies should be selected for any particular interaction with the middleware. A contextual pattern mechanism facilitates the succinct expression of both coarse- and fine-grain policy contexts. Policies may be specified and altered dynamically, and may themselves take account of dynamic conditions. The framework contains no hard-wired policies; instead, all policies can be configured.Comment: Submitted to Dependable and Adaptive Distributed Systems Track, ACM SAC 200

    Why Or Why Not Service Oriented Architecture

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    [[abstract]]Service Oriented Architecture (SOA) is a new computation technology in these years. Though this architecture, business application can be wrapped as loosely-coupled component. Base on business needs, connecting different component into necessary services of real process, enterprise can utilize existing applications repeatedly, then integrate the independent applications into new services. This paper focused on the issues on which enterprise needs to consider before implementation of SOA. We have a further discussion on advantages and disadvantages for adopting SOA. Once SOA is implemented what we need to care about? It is helpful on your long term success if you can thoroughly understand the key points of this paper, then the enterprise can well evaluate if its information system needs to adopt SOA.[[conferencetype]]國際[[conferencelocation]]Zhangjiajie, Chin

    Two ways to Grid: the contribution of Open Grid Services Architecture (OGSA) mechanisms to service-centric and resource-centric lifecycles

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    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 ‘first-order’) 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 ‘second-order’) 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

    Poseidon: Non-server WEB Forms Off-line Processing System

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    The proposed Poseidon system is based on email services of filled forms instead of WEB server based services. This approach is convenient especially for small applications or small-medium companies. It is based on PDF forms that are available on a WEB page. PDF forms can be downloaded, off-line filled in, printed and finally sent by email for final processing. Data are actually stored in the local outbox waiting for a connection to a mail server. This follows an idea of the standard "paper" letter sending. Filled in data are actually sent when a user is on-line, therefore a user is "free" of being on-line when filling the forms. When the PDF form is processed on the recipient side, answer is sent back via email as well. Typical application is e.g. in conference management systems, systems for submission to journals etc. The great advantage of the PDF forms use is that they can be easily made or modified by a non-specialized administrative person easily.Comment: Draft of the paper submitted to International Journal of Computers, ISSN: 2367-889

    Engineering of service-oriented automation systems: a survey

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    The evolution of manufacturing systems and the emergence of decentralised control require flexibility at various levels of their lifecycle. New emerging methods, such as multi-agent and service-oriented systems are major research topics in the sense of revitalizing the traditional production procedures. This paper takes an overview of the serviceoriented approach in terms of platform and engineering tools, from the perspective of automation and production systems. From the basic foundation to the more complex interactions, service-oriented architectures and its implementation in form of web services provide diverse and quality proved features that are welcome to different states of the production systems’ life-cycle. Key elements are the concepts of modelling and collaboration, which enhance the automatic binding and synchronisation of individual low-value services to more complex and meaningful structures. Such interactions can be specified by Petri nets, a mathematically well founded tool with features that enhance towards the modelling of systems. The right application of different methodologies together should motivate the development of service-oriented manufacturing systems that embrace the vision of collaborative automation.The authors would like to thank the European Commission and the partners of Network of Excellence “Innovative Production Machines and Systems” (http://www.iproms.org/) and the SOCRADES project (http://www.socrades.eu) for their support.info:eu-repo/semantics/publishedVersio

    Engineering of service-oriented automation systems: a survey

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    The evolution of manufacturing systems and the emergence of decentralised control require flexibility at various levels of their lifecycle. New emerging methods, such as multi-agent and service-oriented systems are major research topics in the sense of revitalizing the traditional production procedures. This paper takes an overview of the serviceoriented approach in terms of platform and engineering tools, from the perspective of automation and production systems. From the basic foundation to the more complex interactions, service-oriented architectures and its implementation in form of web services provide diverse and quality proved features that are welcome to different states of the production systems’ life-cycle. Key elements are the concepts of modelling and collaboration, which enhance the automatic binding and synchronisation of individual low-value services to more complex and meaningful structures. Such interactions can be specified by Petri nets, a mathematically well founded tool with features that enhance towards the modelling of systems. The right application of different methodologies together should motivate the development of service-oriented manufacturing systems that embrace the vision of collaborative automation.The authors would like to thank the European Commission and the partners of Network of Excellence “Innovative Production Machines and Systems” (http://www.iproms.org/) and the SOCRADES project (http://www.socrades.eu) for their support.info:eu-repo/semantics/publishedVersio

    Specifications of a device interface for service-oriented automation control components

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    Service-oriented paradigm is being used to develop distributed and reconfigurable control solutions for factory automation environments. Since service-oriented automation control components are logical entities that provide and consume services, they may have an interface that maps the logical processes into the actions of the representative physical mechatronics. The inter-connection with the physical hardware devices, namely accessing I/Os, is a crucial issue to achieve the vertical IT-enterprise integration in these service-oriented systems, covering the shop floor device control level. This paper describes a device interface approach, in the context of a service-oriented control architecture, in which High-level Petri nets are used as the control description to access to the physical device. The outgoing features of the solution allow integrating the physical behavior into the control of automation components and consequently thereby incorporate it in the modular service-oriented control architecture

    Security in Pervasive Applications: A Survey

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    We survey some critical issues arising in pervasive applications, in particular the interplay between context-awareness and security. We shall outline the techniques adapted for guaranteeing applications to securely behave in the digital environment they are part of

    Automated UML models merging for web services testing

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    International audienceThis paper presents a method for merging UML models which takes place in a quality evaluation framework for Web Services (WS). This framework, called iTac-QoS, is an extended UDDI server (a yellow pages system dedicated to WS), using model based testing to assess quality. WS vendors have to create UML model of their product and our framework extracts tests from it. Depending on the results of the test execution, a mark is given to WS. This mark gives to the cus- tomers an idea about the quality of WS they find on our UDDI server. Up today, our framework was limited to WS which did not use other WS. This was justified by the fact that it is impossible for vendors to cre- ate a good model of a foreign product. Our method for model merging solves this problem: each vendor produces models of its own product, and we automatically merge the different models. The resulting model from this merging represents the composition of the different WS. For each type of diagram present in the models (class, instance or state- chart diagram), a method is proposed in order to produce a unique model. In addition to this, a solution is proposed to merge all OCL code in the class modeling the WS under test. Unfortunately, this pro- cess introduces inconsistencies in the resulting model, that falsify the results of the subsequent test generation phase. We thus propose to detect such inconsistencies in order to distinguish inconsistent and un- reachable test targets
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