1,858 research outputs found

    Interoperability and portability of cloud service enablers in a PaaS environment

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    Nowadays, the competition in the telecommunications market is exciting and new entities with value-added services have emerged over the core network of Telecommunications operators (Telcos). These new participants have taken out the operators’ relevance since they are entirely agnostic from infrastructure service connectivity. Therefore Telcos, like Portugal Telecom Inovação (PTIN), need to focus on the provision of services to a user’s point of view to not become just a dumb-pipe between the consumers and Cloud service providers. This paper proposes a definition of a distributed architecture that allows developers to create and expose services through a Service Delivery Platform (SDP). The benefit of such Cloud-enabled SDP architecture is the portability of service enablers between Platform-as-a-Service (PaaS) providers through a standardized API. Service developers may thus select the more suitable PaaS offering in order to build on-top applications, based on the performance required by a service. An example of applications which can take advantage from more versatile Cloud platforms, is the delivery of mobile context-aware services that react to both environment and user conditions selecting the right type of content (e.g. photos, videos, etc.) to deliver.(undefined

    DALiuGE: A Graph Execution Framework for Harnessing the Astronomical Data Deluge

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    The Data Activated Liu Graph Engine - DALiuGE - is an execution framework for processing large astronomical datasets at a scale required by the Square Kilometre Array Phase 1 (SKA1). It includes an interface for expressing complex data reduction pipelines consisting of both data sets and algorithmic components and an implementation run-time to execute such pipelines on distributed resources. By mapping the logical view of a pipeline to its physical realisation, DALiuGE separates the concerns of multiple stakeholders, allowing them to collectively optimise large-scale data processing solutions in a coherent manner. The execution in DALiuGE is data-activated, where each individual data item autonomously triggers the processing on itself. Such decentralisation also makes the execution framework very scalable and flexible, supporting pipeline sizes ranging from less than ten tasks running on a laptop to tens of millions of concurrent tasks on the second fastest supercomputer in the world. DALiuGE has been used in production for reducing interferometry data sets from the Karl E. Jansky Very Large Array and the Mingantu Ultrawide Spectral Radioheliograph; and is being developed as the execution framework prototype for the Science Data Processor (SDP) consortium of the Square Kilometre Array (SKA) telescope. This paper presents a technical overview of DALiuGE and discusses case studies from the CHILES and MUSER projects that use DALiuGE to execute production pipelines. In a companion paper, we provide in-depth analysis of DALiuGE's scalability to very large numbers of tasks on two supercomputing facilities.Comment: 31 pages, 12 figures, currently under review by Astronomy and Computin

    Adding Policy-based Control to Mobile Hosts Switching between Streaming Proxies

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    We add a simple policy-based control component to mobile hosts that enables them to control the continuous reception of live multimedia content (e.g. a TV broadcast) while they switch between different distributors of that content. Policy-based control provides a flexible means to automate the switching behavior of mobile hosts. The policies react to changes in the mobile host's environment (e.g. when a hotspot network appears) and determine when and how to invoke an earlier developed application-level protocol to discover the capabilities (e.g. supported encodings) of the content distributors and to execute the switches. The design of the control component is based on the IETF policy model, but extended and applied at the application-level instead of at the network-level. We implemented the system and deployed it in a small-scale test bed

    Incorporating Agile with MDA Case Study: Online Polling System

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    Nowadays agile software development is used in greater extend but for small organizations only, whereas MDA is suitable for large organizations but yet not standardized. In this paper the pros and cons of Model Driven Architecture (MDA) and Extreme programming have been discussed. As both of them have some limitations and cannot be used in both large scale and small scale organizations a new architecture has been proposed. In this model it is tried to opt the advantages and important values to overcome the limitations of both the software development procedures. In support to the proposed architecture the implementation of it on Online Polling System has been discussed and all the phases of software development have been explained.Comment: 14 pages,1 Figure,1 Tabl

    A WebRTC Video Chat Implementation Within the Yioop Search Engine

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    Web real-time communication (abbreviated as WebRTC) is one of the latest Web application technologies that allows voice, video, and data to work collectively in a browser without a need for third-party plugins or proprietary software installation. When two browsers from different locations communicate with each other, they must know how to locate each other, bypass security and firewall protections, and transmit all multimedia communications in real time. This project not only illustrates how WebRTC technology works but also walks through a real example of video chat-style application. The application communicates between two remote users using WebSocket and the data encryption algorithm specified in WebRTC technology. This project concludes with a description of the WebRTC video chat application’s implementation in Yioop.com, a PHP-based internet search engine
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