422,524 research outputs found

    Energy-efficient wireless communication for mobile multimedia terminals

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    This paper presents a control system that adapts a WCDMA receiver at run-time to minimize the energy consumption while providing an adequate Quality of Service (QoS). The adaptation is done at run-time, because of the dynamic environment of a mobile receiver. Simulations show that run-time adaptation to the environment decreases the energy consumption of a receiver and also improves other QoS parameters, such as a higher throughput and a lower frame error rate

    Dynamic Adaptation of Stability Periods for Service Level Agreements

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    ASG - Techniques of Adaptivity

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    The introduction of service-orientation leads to significant improvements regarding flexibility in the choice of business partners and IT-systems. This requires an increased adaptability of enterprise software landscapes as the environment is more dynamic than the ones in traditional approaches. In this paper we present different types of adaptation scenarios for service compositions and their implementation in a service provision platform. Based on experiences from the Adaptive Services Grid (ASG) project, we show how dynamic adaptation strategies are able to support an automated selection, composition and binding of services during run-time

    Context-aware Authorization in Highly Dynamic Environments

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    Highly dynamic computing environments, like ubiquitous and pervasive computing environments, require frequent adaptation of applications. Context is a key to adapt suiting user needs. On the other hand, standard access control trusts users once they have authenticated, despite the fact that they may reach unauthorized contexts. We analyse how taking into account dynamic information like context in the authorization subsystem can improve security, and how this new access control applies to interaction patterns, like messaging or eventing. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS), in smart home security

    Design and evaluation of novel scalability techniques for adaptation over heterogeneous networks

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    This paper addresses the issues concerned with the provision of scalable video services over heterogeneous networks particularly with regards to dynamic adaptation and user’s acceptable quality of service. In order to provide and sustain an adaptive and network friendly multimedia communication service, a suite of techniques that achieved automatic scalability and adaptation are developed using H.264/AVC Extension codec platform. The objective, subjective and real time performances of the techniques are evaluated to assess the Quality of Service (QoS) provided to diverse users with variable constraints and dynamic resources. The techniques are further evaluated with view to establish their performance against state of the art scalable and none-scalable techniques. Several experiments and simulations revealed that the proposed techniques outperformed state-of- the-art and none-scalable(SL) techniques. The designed techniques provide an automated scalability adaptation on the video stream and showed up to 50% gain in scalability adaptation against single layer (SL) and none-combined scalability techniques

    Pathways to climate adapted and healthy low income housing

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    AbstractThis report presents the findings from the “Pathways to Climate Adapted and Healthy Low Income Housing” project undertaken by the CSIRO Climate Adaptation Flagship in partnership with two organisations responsible for providing social housing in Australia.The project was based on the premise that interactions between people, housing, and neighbourhood are dynamic and best viewed as a complex, dynamic social-ecological system. Using social housing as a case study, the objectives of the project were to:Model vulnerability of housing and tenants to selected climate change impacts;Identify/evaluate engineering, behavioural and institutional adaptation options;Scope co-benefits of climate adaptation for human health and well-being; andDevelop house typologies and climate analogues for national generalisations.This project was developed with the rationale that a multi-level focus on the cross-scale interactions between housing, residents, neighbourhood, and regional climate was vital for understanding the nature of climate change vulnerability and options for adaptation. The climate change hazards that were explored were increasing temperatures and more frequent and severe heatwaves in the context of heat-related health risks to housing occupants, and changes in radiation, humidity, and wind, in relation to material durability and service life of housing components and the implications for maintenance.Please cite as:Barnett G, Beaty RM, Chen D, McFallan S, Meyers J, Nguyen M, Ren Z, Spinks A, and Wang, X 2013 Pathways to climate adapted and healthy low income housing, National Climate Change Adaptation Research Facility, Gold Coast, pp. 110.This report presents the findings from the \u27Pathways to Climate Adapted and Healthy Low Income Housing\u27 project undertaken by the CSIRO Climate Adaptation Flagship in partnership with two organisations responsible for providing social housing in Australia.The project was based on the premise that interactions between people, housing, and neighbourhood are dynamic and best viewed as a complex, dynamic social-ecological system. Using social housing as a case study, the objectives of the project were to:Model vulnerability of housing and tenants to selected climate change impacts;Identify/evaluate engineering, behavioural and institutional adaptation options;Scope co-benefits of climate adaptation for human health and well-being; andDevelop house typologies and climate analogues for national generalisations.This project was developed with the rationale that a multi-level focus on the cross-scale interactions between housing, residents, neighbourhood, and regional climate was vital for understanding the nature of climate change vulnerability and options for adaptation. The climate change hazards that were explored were increasing temperatures and more frequent and severe heatwaves in the context of heat-related health risks to housing occupants, and changes in radiation, humidity, and wind, in relation to material durability and service life of housing components and the implications for maintenance

    Dynamic adaptation of service-based applications: a design for adaptation approach

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    Abstract A key challenge posed by the Next Generation Internet landscape is that modern service-based applications need to cope with open and continuously evolving environments and to operate under dynamic circumstances (e.g., changes in the users requirements, changes in the availability of resources). Indeed, dynamically discover, select and compose the appropriate services in such environment is a challenging task. Self-adaptation approaches represent effective instruments to tackle this issue, because they allow applications to adapt their behaviours based on their execution environment. Unfortunately, although existing approaches support run-time adaptation, they tend to foresee the adaptation requirements and related solutions at design-time, while working under a "closed-world" assumption. In this article our objective is that of providing a new way of approaching the design, operation and run-time adaptation of service-based applications, by considering the adaptivity as an intrinsic characteristic of applications and from the earliest stages of their development. We propose a novel design for adaptation approach implementing a complete lifecycle for the continuous development and deployment of service-based applications, by facilitating (i) the continuous integration of new services that can easily join the application, and (ii) the operation of applications under dynamic circumstances, to face the openness and dynamicity of the environment. The proposed approach has been implemented and evaluated in a real-world case study in the mobility domain. Experimental results demonstrate the effectiveness of our approach and its practical applicability
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