168 research outputs found

    An MDE Approach for Domain based Architectural Components Modelling.

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    International audienceComponent Based Software Engineering (CBSE) is a popular and widely adopted software engineering paradigm that has proven his usefulness and success to increase reusability and efficiency in various application domains. In this paper, we propose a common metamodel of a component to support all the requirements of CBSE taking into account the specificities of each domain. The resulting modeling framework serves primarily to capture the basic concepts of concerns related to component systems development based on the clear separation between the development process, interactions and the domain knowledge. As a proof of concept, we are evaluating the feasibility of our approach through the CCM component model applied to an use case for building systems having real-time requirements

    Container-based network function virtualization for software-defined networks

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    Today's enterprise networks almost ubiquitously deploy middlebox services to improve in-network security and performance. Although virtualization of middleboxes attracts a significant attention, studies show that such implementations are still proprietary and deployed in a static manner at the boundaries of organisations, hindering open innovation. In this paper, we present an open framework to create, deploy and manage virtual network functions (NF)s in OpenFlow-enabled networks. We exploit container-based NFs to achieve low performance overhead, fast deployment and high reusability missing from today's NFV deployments. Through an SDN northbound API, NFs can be instantiated, traffic can be steered through the desired policy chain and applications can raise notifications. We demonstrate the systems operation through the development of exemplar NFs from common Operating System utility binaries, and we show that container-based NFV improves function instantiation time by up to 68% over existing hypervisor-based alternatives, and scales to one hundred co-located NFs while incurring sub-millisecond latency

    Toward sustainable data centers: a comprehensive energy management strategy

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    Data centers are major contributors to the emission of carbon dioxide to the atmosphere, and this contribution is expected to increase in the following years. This has encouraged the development of techniques to reduce the energy consumption and the environmental footprint of data centers. Whereas some of these techniques have succeeded to reduce the energy consumption of the hardware equipment of data centers (including IT, cooling, and power supply systems), we claim that sustainable data centers will be only possible if the problem is faced by means of a holistic approach that includes not only the aforementioned techniques but also intelligent and unifying solutions that enable a synergistic and energy-aware management of data centers. In this paper, we propose a comprehensive strategy to reduce the carbon footprint of data centers that uses the energy as a driver of their management procedures. In addition, we present a holistic management architecture for sustainable data centers that implements the aforementioned strategy, and we propose design guidelines to accomplish each step of the proposed strategy, referring to related achievements and enumerating the main challenges that must be still solved.Peer ReviewedPostprint (author's final draft

    Scalable Video Coding Guidelines and Performance Evaluations for Adaptive Media Delivery of High Definition Content

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    International audienceScalability within media coding allows for content adaptation towards heterogeneous user contexts and enables in-network adaptation. However, there is no straightforward solution how to encode the content in a scalable way while maximizing rate-distortion performance. In this paper we provide encoding guidelines for scalable video coding based on a survey of media streaming industry solutions and a comprehensive performance evaluation using four state of the art scalable video codecs with a focus on high-definition content (1080p)

    The Unitary Patent Package, the Court of Justice of the European Union, and Brexit: (Ir)reconcilable?

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    This is the author accepted manuscript. The final version is available electronically via Westlaw UK.For seventy years, debates in the European patent community have centred on the introduction of a unitary patent system. For an efficient and effective European patent system, there are two key aspects – the promotion of harmonisation and the consideration of wider societal implications. In considering these two key aspects, this article focuses on the role of the Court of Justice of the European Union (CJEU) in the Unitary Patent Package (UPP) and the added complication of Brexit. In doing so, it examines the relevant institutional issues that have arisen in the lead up to the finalisation of the UPP, which continue to cause issues as a result of Brexit, and proposes a new way forward for reconciliation. It is argued that the continued questioning of the role of the CJEU goes against the overarching goal of a harmonised patent system that still considers the wider implications of its decisions

    A Survey on Quality of Service in the Voice Over IP Technology

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    Voice services can be transmitted by circuit switched and packet switched networks (Internet). Voice over Internet Protocol (VoIP) is one of the most attractive and important service in telecommunication networks, current implementations of VoIP have two main types of architectures, which are based on H.323 and Session Initiation Protocol (SIP). However, when the voice traffic is transported over Internet, the packet based transmission may introduce impairments and it has influence on the Quality of Service (QoS) perceived by the end users. The voice quality of VoIP systems depends on many QoS parameters. Particularly, One Way Delay (OWD), jitter and Packet Loss Rate (PLR) have an important impact on voice quality. This survey presents the main concepts relating to the VoIP technology and quality of service issues

    Effectiveness of C6T and W5H in Lean documentation

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    In the Evaluation of software development, Lean is oldest organizational methodology. To improve the performance Lean is having various versions. Documentation plays key role in estimating the performance of project. It is also having features like reorganization of development system. This paper focuses on drawbacks of documentation regarding lean methodology. Documentation will give clear vision and goals of product. To enhance the features of documentation C6T and W5H principles are applied

    You are What you Eat (and Drink): Identifying Cultural Boundaries by Analyzing Food & Drink Habits in Foursquare

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    Food and drink are two of the most basic needs of human beings. However, as society evolved, food and drink became also a strong cultural aspect, being able to describe strong differences among people. Traditional methods used to analyze cross-cultural differences are mainly based on surveys and, for this reason, they are very difficult to represent a significant statistical sample at a global scale. In this paper, we propose a new methodology to identify cultural boundaries and similarities across populations at different scales based on the analysis of Foursquare check-ins. This approach might be useful not only for economic purposes, but also to support existing and novel marketing and social applications. Our methodology consists of the following steps. First, we map food and drink related check-ins extracted from Foursquare into users' cultural preferences. Second, we identify particular individual preferences, such as the taste for a certain type of food or drink, e.g., pizza or sake, as well as temporal habits, such as the time and day of the week when an individual goes to a restaurant or a bar. Third, we show how to analyze this information to assess the cultural distance between two countries, cities or even areas of a city. Fourth, we apply a simple clustering technique, using this cultural distance measure, to draw cultural boundaries across countries, cities and regions.Comment: 10 pages, 10 figures, 1 table. Proceedings of 8th AAAI Intl. Conf. on Weblogs and Social Media (ICWSM 2014
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