9,613 research outputs found

    QoS in wireless sensor networks: survey and approach

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    A wireless sensor network (WSN) is a computer wireless network composed of spatially distributed and autonomous tiny nodes -- smart dust sensors, motes -, which cooperatively monitor physical or environmental conditions. Nowadays these kinds of networks support a wide range of applications, such as target tracking, security, environmental control, habitat monitoring, source detection, source localization, vehicular and traffic monitoring, health monitoring, building and industrial monitoring, etc. Many of these applications have strong requirements for end-to-end delay and losses during data transmissions. In this work we have classified the main mechanisms that have been proposed to provide Quality of Service (QoS) in WSN at Medium Access Control (MAC) and network layers. Finally, taking into account some particularities of the studied MAC- and network-layer protocols, we have selected a real application scenario in order to show how to choose an appropriate approach for guaranteeing performance in a WSN deployed application

    A Self-adaptive Agent-based System for Cloud Platforms

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    Cloud computing is a model for enabling on-demand network access to a shared pool of computing resources, that can be dynamically allocated and released with minimal effort. However, this task can be complex in highly dynamic environments with various resources to allocate for an increasing number of different users requirements. In this work, we propose a Cloud architecture based on a multi-agent system exhibiting a self-adaptive behavior to address the dynamic resource allocation. This self-adaptive system follows a MAPE-K approach to reason and act, according to QoS, Cloud service information, and propagated run-time information, to detect QoS degradation and make better resource allocation decisions. We validate our proposed Cloud architecture by simulation. Results show that it can properly allocate resources to reduce energy consumption, while satisfying the users demanded QoS

    Development of a building information modelling (BIM) migration path model for construction professionals

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    The construction professionals have the notion that by implementing Building Information Modelling (BIM) in construction could overcome problems such as delay, cost overrun, clashes in project design and undesirable quality in construction. However, they failed to take the advantages of the BIM benefit as they are still trying to find the best way to take on board the BIM into current practices. Most of the professionals do not know ‘when’ and ‘how’ to apply BIM throughout the construction lifecycle. Several research models related to BIM has been developed to improve and encourage BIM implementation. Nevertheless, the developed models have limitations in highlighting the steps involved that could assist the construction professionals in implementing BIM effectively in Malaysia. Therefore, this research is aimed to develop a model that would be able to assist Malaysian construction professionals in implementing BIM in a structured way. A semi-structured interview was carried out with respondents that have various experienced and currently involved in BIM projects in the Malaysian construction industry. Findings show that the construction professionals are lacking in knowledge and experience in using BIM in various stages of construction. Thus, they were unable to fully capitalise the benefit of 3D models. Migration path model was proposed and evaluated as a strategic approach for BIM implementation in the Malaysian construction industry. The identification of five (5) activities (BIM Awareness, Develop BIM Strategy, Implement BIM, Monitor BIM and Expand BIM Implementation) with the three (3) enablers (BIM work contract, BIM work process and BIM technology) in the model is expected to be able to assist construction professionals to implement BIM with the right BIM concept and later, the benefit could be obtained for improving construction project. The proposed model could be as a guideline for construction professionals in implementing BIM, specifically in countries that new in BIM. The model is also expected to be able to fill the gap in BIM implementation by supporting the initiatives by the Malaysian government for increasing productivity in construction projects by using new technology like BIM

    Deliverable JRA1.1: Evaluation of current network control and management planes for multi-domain network infrastructure

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    This deliverable includes a compilation and evaluation of available control and management architectures and protocols applicable to a multilayer infrastructure in a multi-domain Virtual Network environment.The scope of this deliverable is mainly focused on the virtualisation of the resources within a network and at processing nodes. The virtualization of the FEDERICA infrastructure allows the provisioning of its available resources to users by means of FEDERICA slices. A slice is seen by the user as a real physical network under his/her domain, however it maps to a logical partition (a virtual instance) of the physical FEDERICA resources. A slice is built to exhibit to the highest degree all the principles applicable to a physical network (isolation, reproducibility, manageability, ...). Currently, there are no standard definitions available for network virtualization or its associated architectures. Therefore, this deliverable proposes the Virtual Network layer architecture and evaluates a set of Management- and Control Planes that can be used for the partitioning and virtualization of the FEDERICA network resources. This evaluation has been performed taking into account an initial set of FEDERICA requirements; a possible extension of the selected tools will be evaluated in future deliverables. The studies described in this deliverable define the virtual architecture of the FEDERICA infrastructure. During this activity, the need has been recognised to establish a new set of basic definitions (taxonomy) for the building blocks that compose the so-called slice, i.e. the virtual network instantiation (which is virtual with regard to the abstracted view made of the building blocks of the FEDERICA infrastructure) and its architectural plane representation. These definitions will be established as a common nomenclature for the FEDERICA project. Other important aspects when defining a new architecture are the user requirements. It is crucial that the resulting architecture fits the demands that users may have. Since this deliverable has been produced at the same time as the contact process with users, made by the project activities related to the Use Case definitions, JRA1 has proposed a set of basic Use Cases to be considered as starting point for its internal studies. When researchers want to experiment with their developments, they need not only network resources on their slices, but also a slice of the processing resources. These processing slice resources are understood as virtual machine instances that users can use to make them behave as software routers or end nodes, on which to download the software protocols or applications they have produced and want to assess in a realistic environment. Hence, this deliverable also studies the APIs of several virtual machine management software products in order to identify which best suits FEDERICA’s needs.Postprint (published version
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