9,613 research outputs found
QoS in wireless sensor networks: survey and approach
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
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
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
Delivering services by building and running virtual organisations
Non peer reviewedPostprin
Deliverable JRA1.1: Evaluation of current network control and management planes for multi-domain network infrastructure
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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