41,635 research outputs found
Experiences and issues for environmental engineering sensor network deployments
Sensor network research is a large and growing area of academic effort, examining technological and deployment issues in the area of environmental monitoring. These technologies are used by environmental engineers and scientists to monitor a multiplicity of environments and services, and, specific to this paper, energy and water supplied to the built environment. Although the technology is developed by Computer Science specialists, the use and deployment is traditionally performed by environmental engineers. This paper examines deployment from the perspectives of environmental engineers and scientists and asks what computer scientists can do to improve the process. The paper uses a case study to demonstrate the agile operation of WSNs within the Cloud Computing infrastructure, and thus the demand-driven, collaboration-intense paradigm of Digital Ecosystems in Complex Environments
InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services
Cloud computing providers have setup several data centers at different
geographical locations over the Internet in order to optimally serve needs of
their customers around the world. However, existing systems do not support
mechanisms and policies for dynamically coordinating load distribution among
different Cloud-based data centers in order to determine optimal location for
hosting application services to achieve reasonable QoS levels. Further, the
Cloud computing providers are unable to predict geographic distribution of
users consuming their services, hence the load coordination must happen
automatically, and distribution of services must change in response to changes
in the load. To counter this problem, we advocate creation of federated Cloud
computing environment (InterCloud) that facilitates just-in-time,
opportunistic, and scalable provisioning of application services, consistently
achieving QoS targets under variable workload, resource and network conditions.
The overall goal is to create a computing environment that supports dynamic
expansion or contraction of capabilities (VMs, services, storage, and database)
for handling sudden variations in service demands.
This paper presents vision, challenges, and architectural elements of
InterCloud for utility-oriented federation of Cloud computing environments. The
proposed InterCloud environment supports scaling of applications across
multiple vendor clouds. We have validated our approach by conducting a set of
rigorous performance evaluation study using the CloudSim toolkit. The results
demonstrate that federated Cloud computing model has immense potential as it
offers significant performance gains as regards to response time and cost
saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape
Prognostics: Design, Implementation, and Challenges
Prognostics is an essential part of condition-based maintenance (CBM), described as predicting the remaining useful life
(RUL) of a system. It is also a key technology for an integrated vehicle health management (IVHM) system that leads
to improved safety and reliability. A vast amount of research has been presented in the literature to develop prognostics
models that are able to predict a system’s RUL. These models can be broadly categorised into experience-based models,
data-driven models and physics-based models. Therefore, careful consideration needs to be given to selecting which
prognostics model to take forward and apply for each real application. Currently, developing reliable prognostics models
in real life is challenging for various reasons, such as the design complexity associated with a system, the high uncertainty
and its propagation in the degradation, system level prognostics, the evaluation framework and a lack of prognostics
standards. This paper is written with the aim to bring forth the challenges and opportunities for developing prognostics
models for complex systems and making researchers aware of these challenges and opportunities
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