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 \ud 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

XSIL: Extensible Scientific Interchange Language

We motivate and define the XSIL language as a flexible, hierarchical, extensible transport language for scientific data objects. The entire object may be represented in the file, or there may be metadata in the XSIL file, with a powerful, fault-tolerant linking mechanism to external data. The language is based on XML, and is designed not only for parsing and processing by machines, but also for presentation to humans through web browsers and web-database technology. There is a natural mapping between the elements of the XSIL language and the object model into which they are translated by the parser. As well as common objects (Parameter, Array, Time, Table), we have extended XSIL to include the IGWDFrame, used by gravitational-wave observatories

Design of a middleware for QoS-aware distribution transparent content delivery

Developers of distributed multimedia applications face a diversity of multimedia formats, streaming platforms and streaming protocols. Furthermore, support for end-to-end quality-of-service (QoS) is a crucial factor for the development of future distributed multimedia systems. This paper discusses the architecture, design and implementation of a QoS-aware middleware platform for content delivery. The platform supports the development of distributed multimedia applications and can deliver content with QoS guarantees. QoS support is offered by means of an agent infrastructure for QoS negotiation and enforcement. Properties of content are represented using a generic content representation model described using the OMG Meta Object Facility (MOF) model. A content delivery framework manages stream paths for content delivery despite differences in streaming protocols and content encoding. The integration of the QoS support, content representation and content delivery framework results in a QoS-aware middleware that enables representation transparent and location transparent delivery of content

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

Spaceborne VHSIC multiprocessor system for AI applications

A multiprocessor system, under design for space-station applications, makes use of the latest generation symbolic processor and packaging technology. The result will be a compact, space-qualified system two to three orders of magnitude more powerful than present-day symbolic processing systems

Flexible Language Interoperability

Virtual machines raise the abstraction level of the execution environment at the cost of restricting the set of supported languages. Moreover, the ability of a language implementation to integrate with other languages hosted on the same virtual machine typically constrains the features of the language. In this paper, we present a highly flexible yet efficient approach to hosting multiple programming languages on an objectoriented virtual machine. Our approach is based on extending the interface of each class with language-specific wrapper methods, offering each language a tailored view of a given class. This approach can be deployed both on a statically typed virtual machine, such as the JVM, and on a dynamic virtual machine, such as a Smalltalk virtual machine. We have implemented our approach to language interoperability on top of a prototype virtual machine for embedded systems based on the Smalltalk object model, which provides interoperability for embedded versions of the Smalltalk, Java, and BETA programming languages

The SATIN component system - a metamodel for engineering adaptable mobile systems

Mobile computing devices, such as personal digital assistants and mobile phones, are becoming increasingly popular, smaller, and more capable. We argue that mobile systems should be able to adapt to changing requirements and execution environments. Adaptation requires the ability-to reconfigure the deployed code base on a mobile device. Such reconfiguration is considerably simplified if mobile applications are component-oriented rather than monolithic blocks of code. We present the SATIN (system adaptation targeting integrated networks) component metamodel, a lightweight local component metamodel that offers the flexible use of logical mobility primitives to reconfigure the software system by dynamically transferring code. The metamodel is implemented in the SATIN middleware system, a component-based mobile computing middleware that uses the mobility primitives defined in the metamodel to reconfigure both itself and applications that it hosts. We demonstrate the suitability of SATIN in terms of lightweightedness, flexibility, and reusability for the creation of adaptable mobile systems by using it to implement, port, and evaluate a number of existing and new applications, including an active network platform developed for satellite communication at the European space agency. These applications exhibit different aspects of adaptation and demonstrate the flexibility of the approach and the advantages gaine