120 research outputs found
Dependability and Security in Medical Information System
This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Medical Information Systems (MIS) help medical practice and health care significantly. Security and dependability are two increasingly important factors for MIS nowadays. In one hand, people would be willing to step into the MIS age only when their privacy and integrity can be protected and guaranteed with MIS systems. On the other hand, only secure and reliable MIS systems would provide safe and solid medical and health care service to people. In this paper, we discuss some new security and reliability technologies which are necessary for and can be integrated with existing MISs and make the systems highly secure and dependable. We also present an implemented Middleware architecture which has been integrated with the existing VISTA/CPRS system in the U.S. Department of Veterans Affairs seamlessly and transparently
Complex networks-based control strategies for multi-terminal HVDC transmission lines
The work proposes and analizes complex network-based controllers for HVDC transmission
lines. Two different control approaches are studied: Distributed PID strategies,
which take into account just local information of the state of each single node,
and Global PID algorithms, in which the control action for each node depends on
the state of the whole network. Both control techniques are tested and numerically
validated on a model of the North Sea Transnational Grid, which is a project of connecting
already existing off-shore power plants in northern Europe countries with
each other and with mainland distribution stations.
The thesis is structured in seven chapters: the first chapter is an introducion
about HVDC transmission lines, the second contains the main theoretical aspects
of complex networks, the third and fourth chapter are more technical and they
are about the study case. The above indicated control strategies are compared
and discussed along with the simulation results in chapters five and six. Finally
conclusions and suggestions for further research works are drawn in chapter seven.Incomin
Distributing power, a transition to a civic energy future: Report of the Realising Transition Pathways Research Consortium âEngine Roomâ
The overarching challenge for UK energy policy is to
ensure the delivery of secure, affordable energy in a
way that meets the emission reductions targets laid
out in the Climate Change Act (2008). The EPSRCfunded
Transition Pathways (TP) and, more recently,
Realising Transition Pathways (RTP) projects have both argued that multiple logics of governance, ownership, and control of the electricity system can be followed to address the energy trilemma. This work has developed three transition pathways for the UK energy system, each driven by different governance patterns. Each pathway has a specific technological mix, institutional architecture, and societal drivers. These pathways are:
Central Co-ordination: Central to this pathway
is the role of the nation state in actively delivering the transition.
Market Rules: After the creation of a broad
policy framework, the state allows competition
and private companies to deliver sustainable,
affordable energy.
Thousand Flowers: This pathway is characterised by a greatly expanded role for civil society in delivering distributed low-carbon generation.
The following report focuses on the Thousand
Flowers pathway. There is growing interest, from a range of stakeholders, in the potential of distributed low-carbon electricity generation in delivering a low-carbon energy system. Yet there are still significant gaps in understanding, particularly regarding the feasibility of scaling up
distributed generation from technological, governance, regulation, policy, and financial perspectives. The aim of this report is to address these gaps within the context of the Thousand Flowers pathway. This research was carried out by the âEngine Roomâ of the EPSRC-funded Realising Transition Pathways (RTP) consortium. The âEngine Roomâ was established to facilitate interdisciplinary work across the consortium
and consists of research fellows and doctoral
researchers from different fields in the nine partner
institutions. Engine Room workshops and meetings
give researchers the space to present their work
and develop and exchange ideas with their peers.
This report is an output of a series of interdisciplinary Engine Room workshops held throughout 2013/14 which also drew on contributions from energy industry stakeholders. These workshops brought together the current research and cumulative findings of the Realising Transition Pathways consortium, to examine the consequences of a transition from a centralised energy system to one where distributed generation plays a much greater role (50% of final electricity demand), and is delivered by a civic energy sector. In this report we do not present any panaceas, attempt to preference a civil response to energy transition,
or claim technological infallibility. We do, however,
explore the potential of a distributed energy future and investigate the technological trajectory it could follow, along with an institutional architecture compatible with its development. We acknowledge throughout that this is a challenging but realistic system transition
Distributing Power: A transition to a civic energy future
There is growing interest, from a range of stakeholders, in the potential of distributed low-carbon electricity generation in delivering a low-carbon energy system. Yet there are still significant gaps in understanding, particularly regarding the feasibility of scaling up distributed generation from technological, governance, regulation, policy, and financial perspectives. The aim of this report is to address these gaps within the context of the Thousand Flowers pathway
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Novel processes for smart grid information exchange and knowledge representation using the IEC common information model
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The IEC Common Information Model (CIM) is of central importance in enabling smart grid interoperability. Its continual development aims to meet the needs of the smart grid for semantic understanding and knowledge
representation for a widening domain of resources and processes. With smart grid evolution the importance of information and data management has become an increasingly pressing issue not only because far more data is being generated using modern sensing, control and measuring devices but
also because information is now becoming recognised as the âintegral componentâ that facilitates the optimal flexibility required of the smart grid. This thesis looks at the impacts of CIM implementation upon the landscape of smart grid issues and presents research from within National Grid
contributing to three key areas in support of further CIM deployment. Taking the issue of Enterprise Information Management first, an information management framework is presented for CIM deployment at National Grid. Following this the development and demonstration of a novel secure cloud
computing platform to handle such information is described. Power system application (PSA) models of the grid are partial knowledge representations of a shared reality. To develop the completeness of our understanding of this reality it is necessary to combine these representations.
The second research contribution reports on a novel methodology for a CIM-based
model repository to align PSA representations and provide a
knowledge resource for building utility business intelligence of the grid.
The third contribution addresses the need for greater integration of information relating to energy storage, an essential aspect of smart energy management. It presents the strategic rationale for integrated energy modeling and a novel extension to the existing CIM standards for modeling grid-scale energy storage. Significantly, this work has already contributed to a larger body of work on modeling Distributed Energy Resources currently under development at the Electric Power Research Institute (EPRI) in the
USA.Dr. Martin Bradley on behalf of National Grid Plc. and the Engineering and Physical
Sciences Research Council (EPSRC
Understanding the Impact of Large-Scale Power Grid Architectures on Performance
Grid balancing is a critical system requirement for the power grid in matching the supply to the demand. This balancing has historically been achieved by conventional power generators. However, the increasing level of renewable penetration has brought more variability and uncertainty to the grid (Ela, Diakov et al. 2013, Bessa, Moreira et al. 2014), which has considerable impacts and implications on power system reliability and efficiency, as well as costs. Energy planners have the task of designing infrastructure power systems to provide electricity to the population, wherever and whenever needed. Deciding of the right grid architecture is no easy task, considering consumersâ economic, environmental, and security priorities, while making efficient use of existing resources.
In this research, as one contribution, we explore associations between grid architectures and their performance, that is, their ability to meet consumersâ concerns. To do this, we first conduct a correlation analysis study. We propose a generative method that captures path dependency by iteratively creating grids, structurally different. The method would generate alternative grid architectures by subjecting an initial grid to a heuristic choice method for decision making over a fixed time horizon. Second, we also conduct a comparative study to evaluate differences in grid performances. We consider two balancing area operation types, presenting different structures and coordination mechanisms. Both studies are performed with the use of a grid simulation model, Spark! The aim of this model is to offer a meso-scale solution that enables the study of very large power systems over long-time horizons, with a sufficient level of fidelity to perform day-to-day grid activities and support architectural questions about the grids of the future. More importantly, the model reconciles long-term planning with short-term grid operations, enabling long-term projections validation via grid operations and response on a daily basis. This is our second contribution
Transversal Merge Operation : A Nondominated Coterie Construction method for distributed mutual exclusion
A coterie is a set of subsets (called quorums) of the processes in a distributed system such that any two quorums intersect with each other and is mainly used to solve the mutual exclusion problem in a quorum-based algorithm. The choice of a coterie sensitively affects the performance of the algorithm and it is known that nondominated (ND) coteries achieve good performance in terms of criteria such as availability and load. On the other hand, grid coteries have some other attractive features : 1) A quorum size is small, which implies a low message complexity, and 2) a quorum is constructible on the fly, which benefits a low space complexity. However, they are not ND coteries unfortunately. To construct ND coteries having the favorite features of grid coteries, we introduce the transversal merge operation that transforms a dominated coterie into an ND coterie and apply it to grid coteries. We call the constructed ND coteries ND grid coteries. These ND grid coteries have availability higher than the original ones, inheriting the above desirable features from them. To demonstrate this fact, we then investigate their quorum size, load, and availability, and propose a dynamic quorum construction algorithm for an ND grid coterie
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